Micro Motion Liquid Density Meter Standard and Advanced Electronics - Model 7835, 7845, 7846, 7847 Manuals & Guides

Download

Technical Manual

78355080_US, Rev. D December 2008

7835/7845/7846/7847

Micro Motion

7835/7845/7846/7847 Liquid Density Meter

Standard and Advanced Electronics

Contents 7835/45/46/47 Technical Manual

Micro Motion

pursues a policy of continuous development and product improvement. The specification in this document

may therefore be changed without notice. To the best of our knowledge, the information contained in this document is

accurate and Micro Motion

No part of this document may be photocopied or reproduced without prior written consent of Micro Motion

cannot be held responsible for any errors, omissions or other misinformation contained herein.

Cont-2

7835/45/46/47 Technical Manual Contents

IMPORTANT NOTICE

DO NOT drop the meter. Handle with care.

DO NOT use liquids incompatible with the MATERIALS OF CONSTRUCTIONS.

DO NOT position RUPTURE DISC where failure could cause personal injury.

DO NOT allow axial loading from PIPEWORK STRESSES to exceed ½ TONNE.

DO NOT operate the meter above its RATED PRESSURE.

DO NOT PRESSURE TEST above the specified TEST PRESSURE.

DO NOT expose the meter to excessive vibration (of >0.5g continuous).

ENSURE all ELECTRICAL SAFETY requirements are applied.

ENSURE meter and associated pipework are PRESSURE TESTED to 1½ times the

maximum operating pressure after installation.

ENSURE meter is not TRANSPORTED when it contains hazardous fluids. This includes fluids that may have leaked into, and are still contained, within the case. Returns Forms are included as Appendix J.

Cont-3

Contents 7835/45/46/47 Technical Manual

Contents

Chapter 1 Introduction

1.1 About this manual ......................................................................................................................1-1

1.2 Product Overview.......................................................................................................................1-2

1.3 Meter Product Range .................................................................................................................1-2

1.4 Electronics Product Range........................................................................................................1-3

1.5 Advanced Electronics................................................................................................................1-4

---- Part Number Identification tables for 7835, 7845, 7846 and 7847 ..........................................1-5

Chapter 2 Mechanical Installation

2.1 General ........................................................................................................................................2-1

2.2 Planning an installation .............................................................................................................2-2

2.3 Meter mounting and pipework ..................................................................................................2-3

2.4 Pressure drop in the meter........................................................................................................ 2-6

2.5 Special considerations for hygienic applications ...................................................................2-7

2.6 Post-installation checks ............................................................................................................2-7

Chapter 3 Advanced Unit Electrical Installation and Configuration

3.1 General ........................................................................................................................................3-1

3.2 Planning an electrical installation.............................................................................................3-2

3.3 Electrical installation in safe areas...........................................................................................3-3

3.4 Electrical installation in hazardous areas ................................................................................3-6

3.5 Baseboard configuration ...........................................................................................................3-8

3.6 Baseboard plus HART

3.7 Advanced density post-Installation checks...........................................................................3-10

option board.......................................................................................3-9

Chapter 4 Standard Density Unit Electrical Installation

4.1 General ........................................................................................................................................4-1

4.2 Ground connections ..................................................................................................................4-1

4.3 Use with Flow Computers and Signal Converters...................................................................4-1

4.4 Use with customer’s own equipment .......................................................................................4-2

4.5 Post-installation checks ............................................................................................................4-4

Chapter 5 Entrained Gas Electronics Electrical Installation

5.1 General ........................................................................................................................................5-1

5.2 Ground connections ..................................................................................................................5-1

5.3 Use with Flow Computers and Signal Converters...................................................................5-1

5.4 Use with customer’s own equipment .......................................................................................5-2

5.5 Post-installation checks ............................................................................................................5-3

Chapter 6 Calibration and Performance

6.1 General ........................................................................................................................................6-1

6.2 Interpretation of calibration certificate.....................................................................................6-1

6.3 Calibration...................................................................................................................................6-7

6.4 Performance .............................................................................................................................6-10

Cont-4

7835/45/46/47 Technical Manual Contents

Contents

Chapter 7 Remote Display and Digital Communications

7.1 Introduction ..........................................................................................................................7-1

7.2 Mechanical installation of the 7965 Remote Display......................................................... 7-2

7.3 Safe area electrical installation ........................................................................................... 7-3

7.4 Hazardous area electrical installation ................................................................................ 7-3

7.5 Configuring the baseboard using a Remote Display ........................................................7-4

7.6 Multi-drop installation.......................................................................................................... 7-8

7.7 Electrical installation of computer devices........................................................................ 7-9

Chapter 8 General Maintenance

8.1 General .................................................................................................................................. 8-1

8.2 Fault Analysis ....................................................................................................................... 8-1

8.3 General Maintenance Procedure......................................................................................... 8-1

Chapter 9 Using Adview

9.1 What is Adview?................................................................................................................... 9-1

9.2 Installing Adview .................................................................................................................. 9-1

9.3 Starting Adview .................................................................................................................... 9-2

9.4 Using Adview........................................................................................................................ 9-5

Appendix A 7835 Specification

A.1 Performance.........................................................................................................................A-1

A.2 Mechanical ...........................................................................................................................A-1

A.3 The 7835 meter versions .....................................................................................................A-2

A.4 Safety approvals ..................................................................................................................A-2

Appendix B 7845/46/47 Specification

B.1 Performance.........................................................................................................................B-1

B.2 Mechanical ...........................................................................................................................B-2

B.3 7845/46/47 Meter Versions ..................................................................................................B-2

B.4 Safety Approvals..................................................................................................................B-4

Appendix C 7845/47 Entrained Gas Specification

C.1 Performance.........................................................................................................................C-1

C.2 Mechanical ...........................................................................................................................C-2

C.3 7845/47 meter versions .......................................................................................................C-2

C.4 Safety approvals ..................................................................................................................C-2

Appendix D Electronics Specifications

D.1 Standard electronics ...........................................................................................................D-1

D.2 Standard entrained gas electronics ...................................................................................D-1

D.3 Advanced electronics..........................................................................................................D-1

D.4 Environmental performance ...............................................................................................D-2

Cont-5

Contents 7835/45/46/47 Technical Manual

Contents

Appendix E Baseboard Calculations and Configurable Factors

E.1 Baseboard configuration.................................................................................................... E-1

E.2 Baseboard diagnostics ....................................................................................................... E-4

E.3 Baseboard calculations ...................................................................................................... E-5

Appendix F Specimen Calibration Certificates

Appendix G Conversion Tables and Product Data

G.1 Conversion tables............................................................................................................... G-1

G.2 Product data ........................................................................................................................G-4

Appendix H Modbus Communications

H.1 Introduction ......................................................................................................................... H-1

H.2 Outline of Modbus communications ................................................................................. H-1

H.3 Modbus dialect .................................................................................................................... H-2

H.4 Establishing Modbus communications............................................................................. H-3

H.5 Modbus commands............................................................................................................. H-4

H.6 Modbus register assignments ........................................................................................... H-4

H.7 Index and enumeration codes............................................................................................ H-7

Appendix I HART® Software

I.1 Introduction.............................................................................................................................I-1

I.2 HART

I.3 Electrical installation..............................................................................................................I-3

I.4 HART

I.5 Transmitter specific command structure .............................................................................I-7

I.6 Summary of HART

basics..........................................................................................................................I-1

commands ..................................................................................................................I-4

functionality ........................................................................................I-10

Appendix J Returns Forms

Appendix K Certified System Drawings

Cont-6

7835/45/46/47 Technical Manual Introduction

Chapter 1

Introduction

1.1 About this manual

This manual covers the complete range of Micro Motion® 7835/45/46/47 Liquid Density Meters and the various electronics configurations available.

From the schematic diagram below, you can see which of the chapters in this manual refer to the part icular instrument that you have. The remaini ng chapters can be placed at the back or removed from the manual.

Advanced Electronics

Standard Electronics Entrained Gas Electronics

Chapter 1

HART OPTION

2 3

Chapter 1

7835/45/46/47 LIQUID DENSITY METER

ENTRAINED GAS AMPLIFIERSTANDARD AMPLIFIERADVANCED BASEBOARD

Chapter 1

5 6

REMOTE DISPLAY

CONTENTS

Chapter 1: Introduction Chapter 2: Mechanical Installation Chapter 3: Advanced Unit Electrical

Chapter 4: Standard Unit

Chapter 5: Entrained Gas Unit

Chapter 6: Calibration & Performance Chapter 7: 7965 Remote Display & Digital

Chapter 8: General Maintenance Chapter 9: Using Adview

Installation & Configuration

Electrical Install ation

Communications

Meter Mechanics

Chapter 1

7965 Remote Display

Chapter 1

2 3

6 7 8

Figure 1.1

Page 1-1

Introduction 7835/45/46/47 Technical Manual

1.2 Product Overview

All of the products consist of a mechanical meter and an electronics unit that is normally mounted inside the meter electronics housing. Together, the electronics and meter provide a system for continuous on-line measurement of liquid density and temperature.

In applications where the pipeline te mp era ture could exceed 110°C (230°F), the electronics should be mounted in a Remote Amplifier Box (see Chapters 3 and 4 for more details.)

Electronics Enclosure

transducers

Meter

Figure 1.2

Liquid density is determi ned from the resonant freque ncy of a vibrating tube containing the liquid, and liquid temperature is determined from a 100 Platinum Resistance Thermometer (PRT). For information on the calculation of density and temperature, please refer to Chapter 6 and Appendix G respectively.

1.3 Meter Product Range

The meters are identical m echanically, except for the material used in the wetted parts and the flanges/couplings. A fully welded design is utilised to ensure maximum reliability in the most severe environments. A rupture disc is embodied in the meter end plate furthest from the amplifier housing. This disc will rupture if a pressure build-up occurs within the case, in the unlikely event of a tube assembly leak; the operation of the rupture disc is shown in Figure 2.2.

The range of meters is ou tlined below. For furt her details, please refer to Appendices A to C.

Meter Tube material Features

7835 NI-SPAN-C® Low temperature coeffi ci en t and long te rm sta bi li ty , appr op riate fo r fisc al

7845 316L Stainless

steel

applications.

Good resistance to corrosion.

7846 Alloy C22 Very high resistance to corrosion.

7847 316L Stainless

steel

Designed for the hygiene requireme nts of th e food pro c es sing in dus t ry and has “3A’s” authorisation. Please refer to Section 2.4 for special cleaning and installation requirem ent s in hygi en i c appl i cat ion s .

Page 1-2

7835/45/46/47 Technical Manual Introduction

1.4 Electronics Product Range

The meters described above may be operated with any of the following electronics options. However, the electronics options are not the Standard electronics boards, and so only fit in the extended electronics enclosures provided with an Advanced meter.

It should be noted that the Standard Entrained Gas Electronics are NOT suitable for operation in hazardous areas, whereas all of the other electronics boards are suitable.

For further details of th e performance of the different electronics boards, please refer to the appropriate chapters and Appendices D and E.

Standard Electronics

Density version

Entrained gas version

all directly interchangeable; this is because the Advanced electronics boards are physically longer than

Table 1.1

Basic amplifier circuit providing a frequency signal (indicating liquid density) and PRT resistance (indicating liquid temperature). Interfaces with a Signal Converter or Flow Computer.

Similar amplifier circuit to the above but meter operating at a lo wer frequency which is more insensitive to entrained gas. It is NOT suitable for operation in hazardous areas.

Advanced Electronics

Density version

Entrained gas version

Remote Amplifier Box

Advanced Electronics

Microprocessor control led circuit with a choice of analogue and digital outputs providing a direct measurement of density and temperature. Also providing a selection of calculated parameters and several diagnostic functions.

As above but meter operating at a lower frequency more appropriate for liquids with entrained gas. Suitable for operation in hazardous areas.

Suitable for operation in hazardous areas. 784521A: IIB Approval (ATEX)

784522A: IIC Approval (ATEX) 784523A: CSA Approval 784524A: Non-classified (supplied as spare for customer installation).

Note that the advanced electronics’ amplifier cannot be fitted into the Standard electronics’ Remote Amplifier Box.

Page 1-3

Introduction 7835/45/46/47 Technical Manual

1.5 Advanced Electronics

In contrast to a meter fitted with Standard electronics (which requires a Flow computer or Signal Co nverter for operation), the meter with Advanced electronics will provide a complete measurement system.

An Advanced Baseboard plus meter provides a complete system for measuring liqui d densi ty and liquid temperature. A Remote Display or one of the optional boards may be required if outputs need to be configured in the field o r if additional functionality is required.

For convenience, the Adva nced system design and performance are outlined below ; full performance specifications are given in Appendices D and E.

Option board

Remote Display

7965 DISPLAY

Baseboard

Figure 1.3

1.5.1 Baseboard

The Baseboard can be considered the heart of the system. Along with a liquid density meter, it provides a complete system for measuring liqu id density and liquid temperature. The Baseboard performs a range of useful calculations and provides the follow ing outputs:

 Two fully configurable 4-20mA outputs.  One pulse output providing either an alarm status signal or the meter tube frequency.  An RS485 digital communications link using RTU Modbus protocol.

1.5.2 Option board

The option board fits directly onto the Baseboard. One option board is presently available:

 HART

Only one board may be fitted at a time.

board - providing an additional 4-20mA output and full HART® communications.

1.5.3 Remote Display

The 7965 Remote Display unit is intended for either hand-held or wall-mounted use. It provides a convenient means for displaying calculated data and for con f ig uring or analysing the system set-up. It communicates via th e Base bo ar d RS48 5 digital communication link. One remote display can communicate with a number of meters if they are connected together on the same RS485 link. Further details of the 7965 Display are given in Chapter 7.

Page 1-4

7835/45/46/47 Technical Manual Introduction

PART NUMBER IDENTIFICATION FOR 7835

Code Product

7835

NI-SPAN-C

A 1” ANSI 900 RF B 1” ANSI 600 RF D 1” ANSI 600 RTJ E 1” ANSI 900 RTJ F 1” ANSI 600 RF Smooth Face H 25mm DIN 2635 DN25/PN40 J 25mm DIN 2635/2512 GVD DN25/PN40 L 25mm DIN 2637 RF DN25/PN100 Z Special

A E F

A Standard Stainless Steel for tube, mounted ampl ifier or remote amplifier. B Outer containment (1/4 NPT), stainless ste el for tube , mount ed amp lifiers o r remote amplifie r. C Secondary containment B31.3 (1/2 NPT) for tube, mounted amplifier or remote amplifier (100Bar)

F Tube mounted flat box in stainless steel.

A Std frequency out, EEx ia IIC T4 (-4 0°C…+40°C) or T4 (-40 °C…+70°C) B Advanced board: 2 x 4-20mA outputs, EEx ia IIC T4 (-40°C…+60°C) D

Code Safety Approval and Label J ATEX intrinsically safe (see “On-board Electronics” for rating)

L CSA intrinsically safe (Canada and USA)

A API Degrees (Americas) – Advanced board only. B Base density to API tables (Metric) – Advanced only. C Line density only – Advanced board only. D General process incl. matrix (user data) – Advanc’d only. T Frequency version – no software to configure. Z Special

A Instrument standard. D UKAS calibration (water). E UKAS calibrati on (3 liquids). Z Special Code ASME IX

A None. B Dye penetratio n (internal welds) C Dye penetration (all welds) D Radiography of flange welds + B E Radiography of flange welds + C F Radiography of flange welds

A None X Certificates of material

7835 A A A F B J B A A A

Code Process Connect ions

Liquid Density Meter

Code Material Options

Wetted parts: Ni-Span Wetted parts: Ni-Span Wetted parts: Ni-Span

Code Meter Outer Containment

Code Amplifier Enclosure

tube, S.S. bellows and input, S.S. outer case

tube, S.S. bellows and input, Hastelloy® outer case

tube, S.S. bellows and input, Duplex outer case

Code On-board Electronics

Advanced board: HART

Code Default Configuration

, 3 x 4-20mA outputs, EEx ia IIB T4 (-40°C… +60°C)

Code Calibration

Code Traceability

(Typical Code)

Page 1-5

Introduction 7835/45/46/47 Technical Manual

PART NUMBER IDENTIFICATION FOR 7845

Code Product

7845 316L STAINLESS STE EL L iqu i d Densi t y Mete r

C 1” ANSI 300 RF K 1” ANSI 600 RF H 25mm DIN 2635 DN25/PN40 J 25mm DIN 2635/2512 GVD DN25/PN40 L 25mm DIN 2637 RF DN25/PN100 Z Special

B Wetted parts: 316L Stainless Steel, 316L Stainless Steel outer case D Wetted parts: Alloy C22 bellows, 316L Stainless Steel tube, flanges and outer case. NACE.

A Standard Stainless Steel for tube, mounted amplifier or remote amplifier. B Outer containment (1/4 NPT), stainless steel for tube, mount ed ampl ifiers o r remote ampli fier. C Secondary containment B31.3 (1 /2 NPT) for tube, mounted amplifier or remote amplifier (100Bar)

F Tube mounted flat box in stainless steel. Code On-board Electronics A Std frequency out, EEx ia IIC T4 ( -40°C…+40°C ) or T 4 (-40°C…+70°C ) B Advanced board: 2 x 4-20mA outputs, EEx ia IIC T4 (-40°C…+60°C) D E Entrained gas – frequency output (safe area only) F Entrained gas – Advanced board: 2 x 4-20mA outputs, EEx rating as B.

J ATEX intrinsically safe (see “On-board Electronics” for rating) L CSA intrinsically safe (Canada and USA) S Safe area only (entrained gas option).

A API Degrees (Americas) – Advanced board only. B Base density to API tables (Metric) – Advanced only. C Line density only – Advanced board only. D General process incl. matr ix (user d ata) – Ad vanc’d o nly. T Frequency version – no software to configure. Z Special

A Instrument standard. D UKAS calibration (water). E UKAS calibration (3 liquids). Z Special

A None. B Dye penetration (internal welds) C Dye penetration (all welds) D Radiography of flange welds + B E Radiography of flange welds + C F Radiography of flange welds

A None X Certificates of material

7845 C B A F B J B A A A

Code Process Connections

Code Material Options

Code Meter Outer Containment

Code Amplifier Enclosure

Advanced board: HART

Entrained gas – Advanced board: HART

Code Safety Approval and Label

Code Default Configuration

Code Calibration

, 3 x 4-20mA outputs, EEx ia IIB T4 ( -40°C…+60 °C)

, 3 x 4-20mA outputs, EEx as C.

Code ASME IX

Code Traceability

(Typical Code)

Page 1-6

7835/45/46/47 Technical Manual Introduction

PART NUMBER IDENTIFICATION FOR 7846

Code Product

7846

HASTELLOY

C 1” ANSI 300 RF H 25mm DIN 2635 DN25/PN40 J 25mm DIN 2635/2512 GVD DN25/PN40 Z Special

C Alloy C22 wetted parts, 316L Stainless Steel outer case. NACE

F Tube mounted flat box in stainless steel. Code On-board Electronics A Std frequency out, EEx ia IIC T4 (-4 0°C…+40°C) or T4 (-40 °C…+70°C) B Advanced board: 2 x 4-20mA outputs, EEx ia IIC T4 (-40°C…+60°C) D E Entrained gas – frequency output (safe area only) F Entrained gas – Advanced board: 2 x 4-20mA outputs, EEx rating as B. H

J ATEX intrinsically safe (see “On-board Electronics” for rating) L CSA intrinsically safe (Canada and USA) S Safe area only (entrained gas option).

A Instrument standard. D UKAS calibration (water). E UKAS calibrati on (3 liquids). Z Special

A None. B Dye penetratio n (internal welds) C Dye penetration (all welds) D Radiography of flange welds + B E Radiography of flange welds + C F Radiography of flange welds

A None X Certificates of material

7846 C C A F B J B A A A (Typical Code)

Code Process Connect ions

C22® Liquid Density Meter

Code Material Options

Code Meter Outer Containment

Code Amplifier Enclosure

Advanced board: HART

Entrained gas – Advanced board: HAR T

Code Safety Approval and Label

Code Default Configuration

, 3 x 4-20mA outputs, EEx ia IIB T4 (-40°C… +60°C)

Code Calibration

Code ASME IX

, 3 x 4-20mA outputs, EEx as C.

Code Traceability

Page 1-7

Introduction 7835/45/46/47 Technical Manual

PART NUMBER IDENTIFICATION FOR 7847

Code Product

7847 316L STAINLESS STEEL Li qu id Dens ity Meter (HYGIENIC)

C 1” ANSI 300 RF H 25mm DIN 2635 DN25/PN40 J 25mm DIN 2635/2512 GVD DN25/PN40 P 1” Ladish Tri-Clamp (Hygienic) S 25mm DIN 11851 Z Special

B Wetted parts 316L Stainless Steel, 316L Stainless Steel outer case.

A Standard Stainless Steel for tube, mounted amplifier or remote amplifier.

F Tube mounted flat box in stainless steel.

A Std frequency out, EEx ia IIC T4 ( -40°C…+40°C ) or T 4 (-40°C…+70°C ) B Advanced board: 2 x 4-20mA outputs, EEx ia IIC T4 (-40°C…+60°C) D E Entrained gas – frequency output (safe area only) F Entrained gas – Advanced board: 2 x 4-20mA outputs, EEx rating as B. H

J ATEX intrinsically safe (see “On-board Electronics” for rating) L CSA intrinsically safe (Canada and USA) S Safe area only (entrained gas option). T Safe area only (3A’s approved label).

A API Degrees (Americas) – Advanced board only. B Base density to API tables (Metric) – Advanced only. C Line density only – Advanced board only. D General process incl. matr ix (user d ata) – Ad vanc’d o nly. T Frequency version – no software to configure. Z Special

A Instrument standard. D UKAS calibration (water). E UKAS calibration (3 liquids). Z Special

A None. B Dye penetration (internal welds) C Dye penetration (all welds) D Radiography of flange welds + B E Radiography of flange welds + C F Radiography of flange welds

A None X Certificates of material

7847 C B A F B J B A A A

Code Process Connections

Code Material Options

Code Meter Outer Containment

Code Amplifier Enclosure

Code On-board Electronics

Advanced board: HART

Entrained gas – Advanced board: HART

Code Safety Approval and Label

Code Default Configuration

Code Calibration

, 3 x 4-20mA outputs, EEx ia IIB T4 ( -40°C…+60 °C)

, 3 x 4-20mA outputs, EEx as C.

Code ASME IX

Code Traceability

(Typical Code)

Page 1-8

7835/45/46/47 Technical Manual Mechanical Installation

Chapter 2

Mechanical Installation

2.1 General

This chapter describes t he mechanical installation of the Micro Motion® 7835/45/46/47 Liquid Density Meters.

Remember! ALWAYS handle the meters with care

Figure 2.1

When handling…

 Don’t drop the meter or subject it to sever mechanic a l shock.  Don’t expose the meter to excessive vibration.

When installing…

 Don’t position the rupture disk where failure could cause personal injury.  Ensure axial loading from pipework does not exceed ½ tonne.  Ensure electrical safety requirements are met.  Ensure that the meter and associated pipework are pressure teste d to 1½ time s the maximu m op e rati ng

pressure.

When operating…

 Don’t use liquids incompatible with the construction.  Don’t operate the meter above its rated pressure.

When transporting…

 Ensure the meter does not contain hazardous fluids, including those that may have leaked into the case.

Page 2-1

Mechanical Installation 7835/45/46/47 Technical Manual

2.2 Planning an installation

When planning the installation of a meter it is important to consider the following factor s:

Safety The meter should be orientated such that, if there is a mechanical structure failure within

Serviceability

Installing the meter in a by-pass configurat ion allows it to be removed for servicing or

Performance

the instrument, the liqui d is discharged from the rupture disc in a safe manner. Please refer to figure 2.2b for details.

calibration without affecting the main pipeline. Possible by-pass configurations are shown in Figure 2.2c

Pipe stresses and vibration

Axial load should not exceed ½ tonne, so pipework should ha ve a degree of flexibility. Excessive pipe vibration should be av oide d.

Gas bubbles The presence of gas bubbles can seriously affect the meter performance and so the

following points shou ld be considered:-

 The liquid must alw ays be at a pressure substantially above its vapour pressure.  All pipework couplings and joints must be air tight.  No vortex should be present at the inlet to the meter.  Cavitations, caused by pumping, should not gene rat e bub bles from di s sol ved ga ses.  If a pump is used it is should ‘push’ rather than ‘pull’ the product through the meter.

Note: For entrained gas unit s where the density of aerated m ixtures is to be measured some of the above recommendations may not be applicable.

Meter orientation

 For low flow rates, e.g. 750 litres/hour (2.7 gal/min.), the meter should preferably be

mounted vertically or at an incline, with the flow in an upwards direction.

 If the liquid contains solid particles, the direction of flow should be upwards unless the

particles are large enough not to be carried with the flow, in which case the direction of flow should be reversed.

 The meter should be mounted with the electric cable running downwards thereby

minimising the ingress of water should a cable gland become defective.

Flow rate

 A fast flow rate, e.g. 3000 litres /hour (11 gal/min.), will help to achieve good

temperature equilibrium and ha ve a self -cle an i ng action .

 A low flow rate, e.g. 1000 litres/hour (3.7 gal/min.), is recommended if the product

contains particles which may cause erosio n .

 The meters exhibit a small flow dependent density reading. For flow rates up to 15000

litres per hour (55 ga l/min) and assuming no consequent line pressure or product changes, the maximum density offset will be less than 0.2kg/m

Temperature Stability

 The inlet pipework should be thermally lagged to ensure good temperature

stabilisation.

Page 2-2

7835/45/46/47 Technical Manual Mechanical Installation

2.3 Meter Mounting and Pipework

This section considers in more detai l the moun ting of the meters and the design of the associa ted pipe work, includin g the calculation of pressure drop in the meter.

Installation drawings for all the meter versions are reproduced in the Appendices, along with detailed drawings of the flanges/couplings. The preferre d meth od s of supp ortin g th e met er are show n in Figure 2.2a.

1st

Meter supported in two positions around 1” schedule 80 pipe.

Figure 2.2a: Preferred Methods of Mounting Meter

For continuously high flow rates, the mounting position can be selected to simplify the associated pipework and help minimise the pressure and temperature losses. (See Figure 2.2b below).

2nd

Meter supported in two positions around the immediate pipework.

3rd

Meter supported in two positions around outer case (4” diameter).

Page 2-3

Mechanical Installation 7835/45/46/47 Technical Manual

1st

Electric Cable

2nd

Electric Cable

FLOW

Direction of flow should be reversed for slurries.

Rupture plate blow out

Direction of flow should be reversed for slurrie s .

>60

Rupture plate blow out

FLOW

3rd

Flow rate should be kept high to prevent gas bubbles & sediment from forming on the resonant tube.

FLOW

Rupture plate blow out

Figure 2.2b: Meter Preferred Mounting Angle

Page 2-4

Electric Cable

7835/45/46/47 Technical Manual Mechanical Installation

‘S’ Bend Method

Laminar Flow Method

Orifice Plate Method

Pressure Bend Method

Pitot Tube Method

PUMP

Pump Method

PUMP

CLEANING LIQUID

Direction of Flow

Integral Cleaning System

Figure 2.2c: Typica l By-Pass Pipeline Conf ig urations

Page 2-5

Mechanical Installation 7835/45/46/47 Technical Manual



2.4 Pressure Drop in the Meter

The pressure drop in the meter depends on:

 Flow rate (  Kinematic viscosity (

The table below gives some examples of pressure drop at various flow rates.

Flow Rate Flow Velocity Pressure Drop (litres/hour) 1000 0.6 0.003 0.004* 4000 2.5 0.033 0.048 12000 7.6 0.238 0.345

* Indicates laminar flow (Fluid Density 1.0g/cc)

Calculation of pressure drop in the meter

The meter should be considered as a straight pipe of 23.6mm (0.929”) internal diameter and 1.03m (40.551”) in length. The following formula has b een proven to apply to the meter by measurements at 12000 litre s per hour (44 gal/min).

(

m/s)

= 2cS =10cS

VLf200



h =



Where:

For viscous or laminar flow (Reynolds N umber

Frictional Coefficient (

For turbulent flow (

Frictional Coefficient (

f ) =

greater than 2500)

) =

and:

h = Pressure drop (bars)

= Friction coefficient

L = Pipe length (m) = 1.03 D = Internal pipe diameter (mm) = 23.6

V = Mean fluid velocity (m/s)

 = Fluid density (g/cc)

= 9.81 (m/s2)

R less than 2000)

064.0

where: Pipe

23.0

R =

DV 1000



= Kinematic viscosity (cS)

In addition to the pressure drop ca used by the liquid flow through the instru ment, it will be necessary to calcu late the pressure drop in any associated sample pipework before concluding the system design requirements.

Page 2-6

7835/45/46/47 Technical Manual Mechanical Installation

2.5 Special considerations for h ygienic applications

The 7847 meter is specially designed for use in hygienic applications. The following points should be considered when planning an installation for a hygienic application.

Meter orientation The 7847 should be installed in the vertical plane to prevent the accumulation of product

residue in the convolutions of the bellows, caus ing contamination, especially during the final rinse when cleaning.

Meter mounting The method of meter mounting should be suitable for the application and cleaning processes

Steam cleaning Where it is necessary to sterilise the meter using the stea m cleaning process, ensure the

Post installation Ensure the cable glands, blanking plugs, lid, and seal are in place and tightened to prevent

used. Process seals appropriate for the media should be used.

temperature and duration of cleaning does not exceed 250 °F (121 °C) for a period of 30 minutes. Exceeding this limit may permanently damage the meter’s amplifier circuit.

moisture and dust ingress.

2.6 Post-Installation Checks

After installation the meter should be pressure tested t o 1.5 times the maximum working pressure of the syst em but NOT to a value exceeding the meter test figure shown on the meter label.

CAUTION: If the pressure test figure is exceeded, the meter may be irrevocably damaged.

Page 2-7

Mechanical Installation 7835/45/46/47 Technical Manual

Page 2-8

7835/45/46/47 Technical Manual Advanced Unit Electrical Installation and Configuration

Chapter 3

Advanced Unit Electrical Installation and

Configuration

3.1 General

This chapter describes the electrical installation of the 7835 and the 7845, 7846, 7847 Liquid Density Meters when fitted with the Advanced electronics option.

Option board

Baseboard

Figure 3.1

The first sections of this chapter address the installation and configuration of the Advanced Baseboard, and the later sections concern the Advanced option boards. Further details about the installation of the Remote Display are given in Chapter 7.

Remote Display

7965 DISPLAY

Page 3-1

Advanced Unit Electrical Installation and Configuration 7835/45/46/47 Technical Manual

3.2 Planning an Electrical Installation

When planning the electrical installation of an Advanced unit, it is important to consider the points given below.

Safety

• Electrical installation in hazardous areas requires strict

• For installation of the CSA certified unit in a hazardous area, refer to Append i x K.

• For installation of the A TEX certified unit in a hazardous area, refer to the appropriate safety

instructions booklet (78355015/SI, 7835 5038/SI, or 78355065/SI).

adherence to local codes of practice.

Power supply

Ground connections

Cable parameters

• The Advanced electronics operate from a nominal 24V supply, but will operate from any supply in the range 9.5V to 28V, meas ured at the supply terminals on the baseboard.

• The output circuits on the baseboard are all loop-pow ered and are isolated from the main circuit. If required, the main circuit and the output circuits can be powered from a common power supply.

• When selecting a suitable pow er supply voltage, you must take into account voltage drops caused by the connecting cable (see below) and in hazardous areas, across zener barriers or galvanic isolators.

• The earthing pads on the baseboard (see Figure 3.3a) must make good contact with the meter case via the M3 bolts.

• If a HART baseboard earthing points.

• The 0V power supply lead should be earthed at the supply end, or at the safety barriers if

applicable.

• Where long cable lengths are required the cable resistance may be significant. When operating from a 24V supply in safe areas the following limits apply:

Power supply 260 Remote Display 60 Outputs 500

For further details relating to the maximum line resistance, please refer to Appendix D.

• When calculating the maximum cable lengths please note that the current loop is 2 times the cable length, and so the cable resistance is given by:

• Typical cables would comply with BS5308 Type 1 or 2.

option board is used, the indicated earthing point must make good contact with the

Maximum line resistance (Ω)

2 x (dc resistance per unit length) x (cab le length)

EMC

Page 3-2

• To meet the EC Directive for EMC (Electromagnetic Compatibility), it is recommended that the meter be connected using a suitable instrumentation cable.

The instrumentation cable should have individual screen(s), foil or braid over each twisted pair and an overall screen to cover all cores. Where permissible, the overall screen should be connected to earth at both ends (360° bonded at both ends). The inner individual screen(s) should be connected at only one end, the controller (e.g. signal conver ter) end.

• Note that for intrinsic safety, termination of the inne r individual screen(s) to earth in the hazardous area is NOT generally permitted.

• Metal cable glands should be used where the cables enter the meter amplifier box. Unused cable ports should be fitted with metal blank ing plugs.

• When the 78452 (Advanced Remote Amplifier) is used, the ferrite ring, which is supplied, must be fitted around the connecting cab le. For ins t all ation in hazardous areas, refer to the certified system drawings in Appendix K, and the safety inst ruc ti on bo okl et (7 83 550 1 5/ SI or 78355038/SI) that came with the meter.

7835/45/46/47 Technical Manual Advanced Unit Electrical Installation and Configuration

3.3 Electrical installation in safe areas

All connections to the baseboard are made to terminals 1 to 12 of the terminal block PL2 as shown in Figure 3.2.

Earthing Point

234 5

PULSE 1

ANALOG 1

ANALOG 2

SUPPLY +

DISPLAY

A B

OPTIONAL

BOARD

Analog 1

22mA

2mA

Alarm

Analog 2

22mA

2mA

Alarm

P/U1 P/U2

PRT -

SIG -

SIG +

PRT +

DRIVE

PL1

234

PL2

Earthing Point

Jumper Links

Foam support strip

Figure 3.2: Baseboard Layout

Note: There is no reason to remove the baseboard under normal circumstances. If it is removed, however, care should

be taken, when replacing the board, to push it firmly against the foam strip, as this helps to prevent the board from excessive flexing.

Page 3-3

Advanced Unit Electrical Installation and Configuration 7835/45/46/47 Technical Manual

Figure 3.3 shows a schematic representation of the electrical connection diagram for the Advanced Baseboard and Remote Display in safe areas. In this example, the pulse output is shown driving an alarm device such as a relay.

+5V to 28V

Pulse

Output

Analog Output

(as above)

500Ω MAX

+16V to 28V

500Ω minimum

1000Ω typical

9.5V to 28V dc Power Supply

Load

Advanced

Density

Baseboard

1 +

Pulse

}

2 -

PL2 Connections

3 +

Analog 1

}

4 -

5 +

Analog 2

}

6 -

7 +

Supply

}

Cable Screen 1

Remote Display

Page 3-4

0V Power 2

+ve Power 3

A 4

B 5

Figure 3.3: Connection Diagram (Safe areas)

8 -

9 -

10 +

11 A

12 B

}

Remote

Display

7835/45/46/47 Technical Manual Advanced Unit Electrical Installation and Configuration

3.3.1 Electrical Installation with Signal Converter / Flow Computer

Figure 3.4 shows a typical electrical connection diagram for use in safe areas using flow computers and signal converters.

7835/45/46/47 with

Advanced Electronics

Freq/Alarm

+VE

-VE

Analog 1 (Analog 2)

(5)

+VE

(6)

-VE

Power Supply

+VE

-VE

1000Ω

7950/51/55 7915/25/26/45/46

+ Density Pwr

+ Density Input

- Density Pwr

- Density Input

+ Density Pwr

+ Analog Input

- Density Pwr

- Analog Input

+Density Pwr

- Density Pwr

SEE FLOW

COMPUTER/

SIGNAL

CONVERTER

HANDBOOK

FOR

CONNECTION

DETAILS

Figure 3.4: Electrical connection diagram when using a flow computer / signal converter (Safe area)

Page 3-5

Advanced Unit Electrical Installation and Configuration 7835/45/46/47 Technical Manual

3.4 Electrical installation in hazardous areas

When used in hazardous areas, safety barriers MUST be interposed between the meter and the signal processing equipment. Some of the safety barriers are unsuitable for certain installations, as discussed below.

Note:

• For installation of the CSA certified unit in a hazardous area, refer to Appendix K.

• For installation of the ATEX certified unit in a hazardous area, refer to the appropriate safety

instructions booklet (78355015/SI, 78355038/SI, or 78355065/SI).

3.4.1 Safety Barrier and Galvanic Isolator Selection

3.4.1.1. Power Supply (PL2 terminals 7 and 8)

As a general rule, the IIB safety barrier should be used where possible as this allows the maximum power to the meter, facilitating a wide range of installations and system configurations.

Where the installation requires the IIC safety barrier, it is important to check that sufficient power is available to power the meter and all of the options. The table below summarises the maximum line resistances allowable for the main system configurations assuming a 24V supply and a minimum of 9.5V available at the supply terminals on the baseboard.

Table 3.1

Advanced System combination

Baseboard 340

Baseboard + remote display 260

Baseboard + locally powered remote display 280

Baseboard + HART® board 270

Baseboard + HART® + display 250

Zener Safety Barriers

Power to the main circuit may be obtained through a simple 164Ω barrier or two 300Ω 28V barriers in parallel for IIB applications, or through a single 234Ω 28V barrier in IIC applications.

The main characteristics of the safety barriers are given here. Using this information and the information given in the table above the most suitable barriers for a particular application can be ascertained.

Table 3.2

Type Group

MTL 729P IIB 164 184

MTL 728P IIC 234 253

P&F Z728H IIC 240 250

Note: The power supply input is protected internally by an 8.2V±5% clamp diode and a 1Ω resistor. This limits the maximum current that can flow into the device:

max

Maximum voltage from barrier

Safety Description (

Minimum resistance of barrier/input combination

Maximum line resistance (

) Max. resistance (Ω)

- Minimum voltage at input

) (barrier + cable)

For example, if two 28V, 300Ω barriers are used in parallel, the effective resistance is 150Ω. The maximum current is:

()

95.02.828

max

…and not 185mA, as might be expected if the input protection diode was not present.

Page 3-6

×−

= 134mA

1150

7835/45/46/47 Technical Manual Advanced Unit Electrical Installation and Configuration

Galvanic Isolators

Galvanic isolators are suitable for powering the main board in IIB applications, but are NOT suitable for powering the main board in

IIC applications. Also, IIC isolators are not suitable for use when Modbus communications are required.

The main characteristics of the galvanic isolators are given here. Using this information and the information given in the table above, the most suitable galvanic isolators for a particular application can be ascertained.

Table 3.3

Type Group

Max output impedance (

)

MTL 3022 IIB 165

P&F KFD2-SD-Ex1.36 IIB 160

P&F KFD2-SL-Ex1.36 IIB 160

MTL 5022 IIB 143

3.4.1.2. Analogue (4 to 20mA) outputs including HART

(PL2 terminals 3 & 4, 5 & 6 and HART PL3 3 & 4)

Any of the zener safety barriers listed on the system certificates are suitable for operation with the Advanced Density analogue outputs. Some galvanic isolators may not be capable of driving the 2mA and 22mA out-of-range alarm states available on the Advanced Density system; for details please check with the barrier supplier.

3.4.1.3. Pulse output

(PL2 terminals 1 & 2)

The pulse output can be configured to output either a status / alarm signal or the resonant frequency of the density meter; the latter requires the safety barrier to have a bandwidth of at least 1 kHz.

The table below indicates which galvanic isolators may be used for frequency configured pulse output; zener barriers may be used for either configuration.

Table 3.4

Isolator type Output description Pulse output configuration

MTL3011 Relay Status / alarm

MTL3012 Solid state (dc to 2kHz) All

MTL4013 Solid state (dc to 5kHz) All

MTL4014 Relay Status / alarm

MTL5011 Relay Status / alarm

MTL5016 Relay Status / alarm

MTL5017 Relay Status / alarm

Page 3-7

Advanced Unit Electrical Installation and Configuration 7835/45/46/47 Technical Manual

3.5 Baseboard Configuration

The baseboard is supplied with one of the following two software versions:

•

General software version - normally used in the food and process industries.

•

Fiscal software version - normally used in Crude oil or refined petroleum applications.

The only difference between the two software versions is the available calculations.

Irrespective of which software version is running, when the unit is received from the factory, it is pre-configured to output the following signals:

Table 3.5

Output Output Parameter

Analog 1 (4-20mA) = Line density (500 to 1500 kg/m³)

Analog 2 (4-20mA) =

Pulse output = Alarm - normally on

For many applications, the factory default configuration described above will be quite acceptable. However, if any of the additional calculated parameters or different output ranges are required, then a simple Baseboard re-configuration can be performed using a Remote Display, or PC.

For details on the available calculations and other Baseboard configuration factors, please refer to Appendix E.

Temperature (0 to 100

°C)

Page 3-8

7835/45/46/47 Technical Manual Advanced Unit Electrical Installation and Configuration

3.6 Baseboard plus HART® Option Board

The HART® option board connects with the Baseboard using the 40-way connector provided and supported by two plastic posts. A tag is provided for connecting to the chassis earth point on the Baseboard.

The HART provide a third analogue output. The unit is always designated as a HART receives a message asking it to do so.

For HART secondary and tertiary outputs.

3.6.1 Electrical Installation for HART® Communications

For safe area installations, electrical connections to the HART® option board are shown in Figure 3.5.

option board is a loop-powered 4-20mA output which can support HART® communications or can be used to

communications, the option board output is regarded as the primary output, and the baseboard outputs as the

slave unit, i.e. it only communicates when it

Note:

• For installation of the CSA certified unit in a hazardous area, refer to Appendix K.

• For installation of the

ATEX certified unit in a hazardous area, refer to the appropriate safety

instructions booklet (78355015/SI, 78355038/SI, or 78355065/SI).

In safe areas, up to 15 HART® slave units may be installed on one HART® communication link. They should be attached in parallel across the two points indicated as a single HART Whenever the HART

HART

communication link, each unit must be given a unique HART® slave address in the range 1 to 15.

address is set to a non-zero value, the output current is automatically set at 4mA. For details of

commands, see Appendix I.

Analogue +

Analogue -

X and Y in Figure 3.5. If more than one HART

HART

Option Board

Network

Resistance

230 to 500Ω

HCC

Hand Held

Communicator

Advanced unit is installed on

Slave Device

Power Supply

Master

HART Device

Figure 3.5: HART® Option Board Electrical Connection Diagram

Page 3-9

Advanced Unit Electrical Installation and Configuration 7835/45/46/47 Technical Manual

3.7 Advanced Density Post-Installation Checks

After installation, the following procedure will indicate to a high degree of confidence that the meter and Advanced system is operating correctly.

1. Measure the supply voltage at the meter amplifier (PL2, pins 7 and 8 – see Figure 3.3a). This voltage should be within

the limits of 9.5 to 24Vdc in safe areas and 9.5 to 20Vdc in hazardous areas. In safe areas, the current to the baseboard should not exceed 80mA.

2. With the meter empty, clean and dry, measure the periodic time of the output signal and check that it is as specified on

the meter calibration certificate (air check), to within the limits given in the table below.

Table 3.6

Meter type

7835 ±60ns

7845 / 46 / 47 ±60ns

Further diagnostic functions are available using the Remote Display or PC, and are outlined in Appendix E.

Air check limit at 20

Added temperature effect

±10ns / °C

300ns / °C

Page 3-10

7835/45/46/47 Technical Manual Standard Density Unit Electrical Installation

Chapter 4

Standard Density Unit

Electrical Installation

4.1 General

This chapter describes the electrical installation of the 7835 and the 7845, 7846, 7847 Liquid Density Meters when fitted with the Standard Density electronics option. The units are identical, except where the 7845, 7846, 7847 meters are to be used at temperatures above 110

4.2 Ground Connections

The earthing pads on the mounting face of the amplifier unit MUST make good contact with the meter case by the M3 cage nuts. The meter should be grounded via the pipework.

The external earth bonding point of the meter is located inside the maintaining amplifier housing. The 0V power supply lead should be earthed at the supply end, or at the safety barriers if applicable.

C (230oF) when the remote amplifier version is recommended - see Appendix B.

4.3 Use with Flow Computers and Signal Converters

4.3.1 System Connections (Hazardous Area only)

When the meter is used in a hazardous area, a safety barrier MUST be interposed between the meter and the signal processing equipment. (See Section 3.4 for information on selecting a safety barrier.)

Note:

x For installation of the CSA certified unit in a hazardous area, refer to Appendix K.

x For installation of the ATEX certified unit in a hazardous area, refer to the appropriate safety instructions

booklet (78355015/SI, 78355038/SI, or 78355065/SI).

4.3.2 System Connections (Safe Area only)

The density system connections are illustrated in Figure 4.1.

7835/45/46/47 with

Standard Electronics

PRT

330:

SUPPLY(+24V)

SIGNAL +VE

SUPPLY(0V)

SIGNAL -VE

PRT PWR +VE

PRT SIG +VE

PRT SIG -VE

PRT PWR -VE

7950/51/55 7915/25/26/45/46

SEE FLOW COMPUTER/ SIGNAL CONVERTER HANDBOOK FOR CONNECTION DETAILS

Figure 4.1: Electrical Connection Diagram – 7835/45/46/47 with Standard Electronics

to Flow Computers / Signal Converters (SAFE AREAS)

Page 4-1

Standard Density Unit Electrical Installation 7835/45/46/47 Technical Manual

4.4 Use with Customer’s Own Equipment

4.4.1 System Connections (Safe Area only)

Power supply to Density Meter: 15.5 to 33Vdc, 25mA min. Power supply to PRT: 5mA max.

The frequency at which the meter is operating can be detected by using a series resistor in the +VE power line. The value of resistance to be used for a given supply voltage must not exceed the value obtained from the LOAD RESISTANCE NOMOGRAM (Figure 4.3).

The electrical connections to be made are shown in Figure 4.2.

7835/45/46/47 with

Standard Electronics

SIG

POS +

NEG -

PRT

Note: See LOAD RESISTANCE NOMOGRAM to determine R value.

See Note

1PF

SIGNAL +VE

POWER +VE

POWER VE

SIGNAL VE

PRT SUPPLY +VE

PRT SIGNAL

PRT SUPPLY VE

Figure 4.2: Electrical Connection Diagram

7835/45/46/47 with Standard Electronics to Customer’s Own Equipment (SAFE AREAS)

Note: It is recommended that the actual load resistor should

be 50 ohms less than that given by the Nomogram.

(33)

Maximum Supply Voltage ‘E’

Supply Voltage

Supply Voltage (volts d.c.)

100

200

Maximum Load Resistance (ohms)

Figure 4.3: Load Resistance Nomogram

Page 4-2

for Given Supply Voltage

Maximum Load Resistance

300

400 500 600

700

7835/45/46/47 Technical Manual Standard Density Unit Electrical Installation

4.4.2 System Connections (Hazardous Area only)

Installation of the meter, the safety barriers, and the customer's signal processing equipment is shown in Figure 4.4.

Note:

x For installation of the CSA certified unit in a hazardous area, refer to Appendix K.

x For installation of the ATEX certified unit in a hazardous area, refer to the appropriate safety

instructions booklet (78355015/SI, 78355038/SI, or 78355065/SI).

Note: Whenever there is disagreement between connection details on the figures dealing with Hazardous Areas and Certified System Diagrams, the Certified System Diagrams

are the authoritative documents.

Additionally, the requirements of Figure 4.5 must be met if the meter is to function correctly. Failure to comply with the details shown in Figure 4.5 will not necessarily invalidate the intrinsic safety of the system, only the functioning of the density meter.

7835/45/46/47 with

Standard Electronics

PRT

POS +

NEG -

SIG

HAZARDOUS AREA

ZENER

BARRIERS

1PF

10K:

1PF

SAFE AREA

POWER +VE

SIGNAL +VE

POWER -VE

SIGNAL -VE

PRT SUPPLY +VE

PRT SIGNAL

PRT SUPPLY -VE

Figure 4.4: Electrical Connection Diagram

7835/45/46/47 with Standard Electronics to Customer’s Own Equipment

(Hazardous AREAS)

Page 4-3

Standard Density Unit Electrical Installation 7835/45/46/47 Technical Manual

4.5 Post-Installation Checks

After installation, the following procedure will indicate to a high degree of confidence that the meter is operating correctly.

Measure the current consumption and the supply voltage at the meter amplifier. This should be within the limits:

15.5 to 33Vdc (Safe Areas)

15.5 to 21.5Vdc (Hazardous Areas)

17mA ±1mA (Safe and Hazardous Areas)

With the meter empty, clean and dry, measure the periodic time of the output signal and check that it is as specified on the meter calibration certificate (air check), to within the limits given in the table below.

Table 4.1

Meter type

7835 ±60ns

7845 / 46 / 47 ±60ns

Air check limit at 20

Added temperature effect

±10ns / qC

+300ns / qC

Page 4-4

7835/45/46/47 Technical Manual Entrained Gas Electronics Electrical Installation

Chapter 5

Entrained Gas Electronics

Electrical Installation

5.1 General

This chapter concerns the operation of 7845/47 meters when fitted with the Standard Entrained gas amplifier.

Warning!

7845/47 Entrained Gas Liquid Density Meters with Standard Electronics are NOT intrinsically safe.

5.2 Ground Connections

The earthing pads on the mounting face of the amplifier unit MUST make good contact with the meter case by the M3 cage nuts. The external earth bonding point of the meter is located inside the maintaining amplifier housing. The meter should be grounded via the pipework.

The 0V power supply lead should be earthed at the supply end, or at the safety barriers if applicable.

5.3 Use with Flow Computers and Signal Converters

The 7845/47 E.G. Liquid Density Meter (with Standard Electronics)/flow computer (or signal converter) system can only be operated in SAFE AREAS.

5.3.1 System Connections

The density system connections are illustrated in Figure 5.1 below.

7845/47 E.G.

PRT

68Ω

SUPPLY(+24V)

SIGNAL +VE

SUPPLY(0V)

SIGNAL -VE

PRT PWR +VE

PRT SIG +VE

PRT SIG -VE

PRT PWR -VE

7950/51/55 7915/25/26/45/46

See Flow Computer/ Signal Converter Handbook for connection details.

Figure 5.1: Electrical Connection Diagram

7945/47 E.G. to Flow Computers / Signal Converters

Page 5-1

Entrained Gas Electronics Electrical Installation 7835/45/46/47 Technical Manual

5.4 Use with Customer’s Own Equipment

5.4.1 System Connections for Safe Areas

Warning!

7845/47 Entrained Gas Liquid Density Meters with Standard Electronics are NOT intrinsically safe.

Power supply to Density Meter: 15.5V to 33V d.c., 25mA min. Power supply to PRT: 5mA max.

Note: Typically, for Flow computers/Signal Converters, a 27V supply gives

2.5V peak to peak minimum across 68Ω. The resistor value should be chosen so that the minimum signal voltage is 1.4V peak to peak.

(33)

Supply Voltage (volts d.c.)

Maximum Supply Voltage ‘E’

Supply Voltage

for Given Supply Voltage

Maximum Load Resistance

Maximum Load Resistance (ohms)

80 100 120 140

Figure 5.2: Load Resistance Nomogram

Page 5-2

7835/45/46/47 Technical Manual Entrained Gas Electronics Electrical Installation

SIG

7845/47 E.G.

POS +

NEG -

PRT

1μF

See Note

1μF

Note: See Load Nomogram (Figure 5.2) to determine R value.

SIGNAL +VE

POWER +VE

POWER -VE

SIGNAL -VE

PRT SUPPLY +VE

PRT SIGNAL

PRT SUPPLY -VE

Figure 5.3: Electrical Connection Diagram – 7845/47 E.G. to Customer’s Own Equipment

(SAFE AREAS)

5.5 Post-Installation Checks

After installation, the following procedure will indicate that, to a high degree of confidence, the meter is operating correctly.

Measure the current consumption and the supply voltage at the meter amplifier. This should be within the limits:

15.5V to 33V d.c. 75mA ±10mA

With the meter empty, clean and dry, measure the periodic time of the output signal and check that it is as specified on the meter calibration certificate (air check), to within acceptable limits (e.g. 500ns), after making allowances for different ambient conditions.

Page 5-3

Entrained Gas Electronics Electrical Installation 7835/45/46/47 Technical Manual

Page 5-4

7835/45/46/47 Technical Manual Calibration and Performance

Chapter 6

Calibration and Performance

6.1 General

The 7835, 7845/46/47 Liquid Density Meters and the 7845/47 Entrained Gas Liquid Density Meters are calibrated at the factory, and are supplied with their own test and calibration certificates.

The calibration certificate specifies various calibration constants that allow the user to convert the output periodic time signal from the meter into a density value. (See Appendix F for specimen calibration certificates.)

Important:

If you have a calibration certificate that was issued before 15 February 2007, contact the factory for a new certificate. Pressure coefficient constants are now calculated for sub-sets of the full operating pressure range, and each set is listed on the certificate (See Appendix F for specimen calibration certificates.)

No new instrument calibrations should be required. The pressure coefficients are valid for liquids of all densities.

For units with Standard Electronics, the calibration constants will need to be programmed into a signal processing instrument such as a signal converter. Density calculations are performed on the signal processing instrument.

For units with Advanced Electronics, the calibration constants are pre-programmed into the electronics and normally require no further consideration. The calculations in this chapter are performed by the electronics on the meter.

Important:

If you have obtained a replacement calibration certificate for a Advanced Electronics unit, the set of pressure coefficient constants K20A, K20B, K21A and K21B that fall within your operating pressure range can be programmed into the Advanced Electronics using Adview software (downloadable from web sites listed on the back page).

(If your operating pressure range falls between two of the sets of operating pressure ranges on the new certificate, contact the factory for a new calibration certificate.)

The Advanced Electronics keeps a write-protected copy and a working copy of all coefficients. The integrity of the working coefficients is safe, and so for simplicity it is recommended that the working coefficients only be changed. This is achieved by writing to registers 131 and 132. (See Chapter 9 for a guide to using Adview.)

Alternatively, a new FRAM memory chip can be issued which holds the calibration coefficients. However, in replacing the FRAM device some user configured data may be lost (e.g. upper and lower limits on the analog outputs, matrix referral points, special function, user defined line pressure etc.).

Page 6-1

Calibration and Performance 7835/45/46/47 Technical Manual

6.2 Interpretation of Calibration Certificate

6.2.1 General Density Equation

The basic meter constants, K0, K1 and K2 are computed from the factory calibration on three fluids. Using these constants and the general density equation, the density of the liquid within the meter can be calculated.

The general density equation is:

D = K0 + K1.

Where: D = Uncorrected density of liquid (kg/m

τ = Periodic time (μs) of vibration = 1/f where ‘f’’ is the frequency of vibration.

K0, K1, and K2 = Constants from the Calibration Certificate.

On the calibration certificate, you can see that the basic meter constants (K0, K1, and K2) are determined from a calibration at a temperature of 20°C (68°F) and at a pressure of 1 bar (14.5psi):

• On a metric certificate: DENSITY CALIBRATION AT 20 DEG. C AND AT 1 BARA

• On imperial certificate: DENSITY CALIBRATION AT 68 DEG. F AND AT 14.5 PSIG

If the operating conditions of the meter differ from that of the calibration conditions, the density calculated using equation (1) must be corrected.

6.2.2 Temperature Correction

If the meter operates at temperatures other than 20°C (68°F), a correction to the density calculated using equation (1) must be made using the temperature coefficient constants from your calibration certificate.

The equation used to apply temperature correction is:

= D.[1 + K18.(t - 20)] + K19.(t - 20)............................................................(2)

Where: D

K18 and K19 = Constants from the Calibration Certificate

= Temperature corrected density (kg/m3)

D = Density calculated using equation (1).

t = Temperature (degrees C)

+ K2.

....................................................................................(1)

Note:

1. K18 and K19 are the temperature coefficient constants on the calibration certificate.

6.2.3 Pressure Correction

The meter design has a unique facility to reduce the influence of the line pressure on the density measurement, but a correction may be required for a residual pressure effect.

This residual pressure effect before a pressure correction is shown schematically for the 7835, 7845/46 and 7847 in Figure 6.1, and shown for the 7845/47 E.G. meters in Figure 6.2.

During the calibration of the meter, which is normally performed at a pressure of 1 bar (14.5psi), the pressure influence is also measured. This data is also shown on the calibration certificate (see Appendix F).

The equation used to apply pressure correction is:

= Dt.[1 + K20.(P - 1)] + K21.(P - 1)...............................................................(3)

Where: D

And: K20 = K20A + K20B (P – 1)

Page 6-2

= Temperature and pressure corrected density (kg/m3).

= Temperature corrected density (kg/m3) calculated using equation (2).

P = Pressure in bar absolute.

K21 = K21A + K21B (P – 1)

7835/45/46/47 Technical Manual Calibration and Performance

This residual pressure effect after a pressure correction is shown schematically for the 7835, 7845, 7846 and 7847 in Figure 6.3 through Figure 6.6.

Notes:

1. K20A, K20B, K21A and K21B are the pressure coefficient constants on the calibration certificate.

2. The pressure correction is further enhanced on units that operate above 41 Bar by having sets of pressure coefficient constants covering subsets of the full operating pressure range.

Note that only one set of pressure coefficient constants is selected from your calibration certificate according to your operating pressure range. If your operating pressure range falls within the range of two sets of pressure coefficient constants, contact the factory for a new calibration certificate.

3. If it is required to apply temperature and pressure corrections, the temperature correction is applied first.

Figure 6.1: Pressure effect on 7835/45/46/47 before pressure correction

)

Uncorrected pressure effects on the meter fall within these bands

Density Offset (kg/m

-10

0 20 40 60 80 100 120 140

Pressure (Bar Absolute)

Figure 6.2: Pressure effect on 7845/47 Entrained Gas before pressure correction

)

Density Offset (kg/m

0 5 10 15 20

Pressure (Bar Absolute)

Page 6-3

Calibration and Performance 7835/45/46/47 Technical Manual

Figure 6.3: Residual pressure effect after pressure correction – 7835 (100Bar) units

This figure shows the typical residual error curves after pressure corrections for 7835 (100Bar) units using three sets of pressure coefficient constants. Each set covers a sub-set of the 100Bar range.

Note that only one set of pressure coefficient constants is selected from your calibration certificate according to your operating pressure range. For specimen calibration certificates, see Appendix F.

1.00

0.80

0.60

0.40

0.20

0.00

0 1020 304050607080 90100110

-0.20

-0.40

Magnitude (kg/m3)

-0.60

-0.80

-1.00

The uncertainty specification for a 7835 is indicated by the upper and lower limit lines. The uncertainty for the 7835 pressure coefficients is ±0.003 kg/m addition to the instrument calibration uncertainty of +/-0.15kg/m

New K20 K21

Upp er limit

Low er limit

Pressure (BarG)

. This is in

Figure 6.4: Residual pressure effect after pressure correction – 7835 (150Bar) units

This figure shows the typical residual error curves after pressure correction for 7835 150Bar units using four sets of pressure coefficient constants. Each set covers a sub-set of the 150Bar range.

Page 6-4

1.00

0.80

0.60

0.40

0.20

0.00

0 10203040 5060 7080 90100110120130140150160

-0.20

-0.40

Magnitude (kg/m3)

-0.60

-0.80

-1.00

New K20 K21

Upper limit

Low er limit

P re ssu re (B a rG )

. This is in

7835/45/46/47 Technical Manual Calibration and Performance

Figure 6.5: Residual pressure effect after pressure correction – 7845K (100Bar) units

This figure shows the typical residual error curves after pressure correction for 7845K (100Bar) units using three sets of pressure coefficient constants. Each set covers a sub-set of the 100Bar range.

1.50

1.00

0.50

0.00

0 102030405060708090100110

-0.50

Magnitude (kg/m3)

-1.00

-1.50

The 7845 uncertainty specification is indicated by the upper and lower limit lines. The uncertainty for the 7845K pressure coefficients is ±0.006kg/m

New K20 K21

Uppe r limit

Low er limit

Pressure (BarG)

. This is in

addition to our stated instrument calibration uncertainty of +/-0.035kg/m3.

Figure 6.6: Residual pressure effect after pressure correction – 7845/7846 (50Bar) units

This figure shows the typical residual error curves after pressure correction for 7845/7846 (50Bar) units using one set of pressure coefficient constants. The set covers the full 50 Bar range.

1.00

0.80

0.60

0.40

0.20

0.00

0 102030405060

-0.20

-0.40

Magnitude (kg/m3)

-0.60

-0.80

-1.00

The 7845/7846 uncertainty specification is indicated by the upper and lower limit lines. The uncertainty for the 7845K pressure coefficients is ±0.006kg/m

New K20 K21

Upper limit

Low er limit

P re ssu re (B a rG )

. This is in addition

to our stated instrument calibration uncertainty of +/-0.035kg/m3.

Page 6-5

Calibration and Performance 7835/45/46/47 Technical Manual

6.2.4 Velocity of Sound Correction

The Velocity of Sound (VOS) in the process liquid may have an effect on the accuracy of the indicated density. The calibration of the 7835/45/46/47 sensors has been optimised to a density/VOS relationship as indicated in Figure 6.7.

If the VOS of the process fluid deviates substantially from the relationship in Figure 6.7 it may be desirable to apply a correction. This may be achieved by the simple introduction of a calibration offset using the data in Figure 6.7. Adjustment of the value K0 in the basic equation will achieve this.

Alternatively, the following equations may be used:

Where:

VOS

= Calibration VOS (m/s)

= Liquid VOS (m/s)

may be obtained direct from Figure 6.3 or may be calculated as follows:

= Velocity of sound and temperature corrected density (kg/m3)

= Temperature and pressure corrected density (kg/m3)

D455.1100 +

for a

D9.02690 −

06E4.1

1400D

¨ ¨

for a

−×

of 300kg/m3 to 1100kg/m

of 1100kg/m3 to 1600kg/m

Note:

The velocity of sound sensitivity of the 7845/47 Entrained Gas Liquid Density Meters is ¼ that of the 7835/45/46/47 series meters. Considering the overall accuracy of the 7845/47 E.G. units, it is not necessary to correct for the velocity of sound effect on these sensors.

2600 2400 2200 2000 1800

+2kg/m3

Nominal

-2kg/m3

Velocity of Sound (m/s)

1600 1400 1200 1000

800 600 400 200

200

800

1400

Indicated Density (kg/m3)

Page 6-6

Values shown are the required corrections.

True Density = Indicated Density + Corrections

Figure 6.7: Optimised Velocity of Sound Relationship for 7835/45/46/47

7835/45/46/47 Technical Manual Calibration and Performance

6.3 Calibration

6.3.1 Factory Calibration

The 7835, 7845/6/7 Liquid Density Meters and the 7845/47 Entrained Gas liquid density meters are calibrated prior to leaving the factory against Transfer Standard instruments, traceable to National Standards.

Three fluids are used in the calibration - ambient air whose density is derived from tables, a hydrocarbon oil of about 815kg/m are connected in parallel between two Transfer Standard Instruments on a special flow rig at the factory. During a calibration and as the liquid flows through the instruments, readings are only taken when the indicated densities on the two Transfer Standard Instruments agree. In this way, a high integrity of calibration is achieved.

Measurements are also made under conditions of changing temperature and pressure to establish the magnitude of these effects on the instrument. From all this data, a calibration certificate is generated for each instrument.

Samples of the instruments are further tested by the quality assurance team at the factory to verify the calibration.

density and a high-density fluid in the range 1400 to 1500kg/m3 density. Several of the instruments-under-test

6.3.2 Calibration of Transfer Standards

The Transfer Standard instruments used in the calibration are selected instruments that are calibrated and certified by the UKAS Certified Calibration Laboratory.

Transfer Standard calibration uses a number of ‘density certified’ liquids. The densities of these certified liquids are obtained using the Primary measurement system, whereby glass sinkers of defined volumes are weighed in samples of the liquids.

Calibration is performed by pumping each certified liquid through the Transfer Standard in a closely controlled manner and recording the output signal in each case. A calibration certificate is issued for each Transfer Standard. Calibrations are repeated, typically every six months, producing a well-documented density standard.

6.3.3 Instrument Calibration Certificate

Each instrument is issued with its own calibration certificate (see Appendix F), containing four important pieces of data:

(

a) The instrument serial number.

b) The output signal/density relationship. This is based on three calibration points - air, medium density and high-density

( fluids. The air and high density fluid points are offset to achieve the product velocity of sound/density profile described earlier, however, the signal value at Air Density is also given for check purposes.

(

c) Temperature coefficient data, describing the correction which should be applied to achieve the best accuracy if the

instrument is operating at product temperatures other than 20°C (68°F).

d) Pressure coefficient data, describing the correction that should be applied to achieve the best accuracy if the

( instrument is operating at elevated pressures.

A second page of the calibration certificate is retained by the factory, and contains all the calibration measurements.

6.3.4 Pressure Test

A hydrostatic pressure test is carried out to a pressure value specified on the instrument label and on the instrument calibration certificate. This test loads the instrument structure to a pressure which exceeds the maximum permitted operating pressure of the instrument.

Page 6-7

Calibration and Performance 7835/45/46/47 Technical Manual

6.3.5 Insulation Test

To comply with Intrinsic Safety requirements, a 500Vac insulation test is carried out between the electrical terminals and the instrument case.

6.3.6 Calibration Check Methods

There are two methods employed in calibration checks:

(

a) Air checkpoint, which is simple and convenient and highlights long term drift, corrosion and deposition.

(

b) Liquid calibration verification comprising two choices:

• Drawing off a sample of the liquid being measured and obtaining its density, using a hydrometer (for stable

liquids) or pyknometer (for unstable liquids).

• Using a second density meter.

Ambient Air Check

(a) Isolate, drain and if necessary, disconnect the meter from the pipeline.

b) Clean and dry the wetted parts of the meter and leave them open to the ambient air.

(

c) Apply power to the instrument and check that the time period of the output signal agrees with the 'Air Check' figure

(

shown in the calibration certificate, to within acceptable limits (e.g. 60ns or 500ns for the E.G. units).

Some variation between the two figures is to be expected due to changes in ambient air conditions. The density indication if using the K0, K1 and K2 factors will be about -0.9kg/m

because the basic density equation has been

optimised for best performance over the normal operating density range.

This test will indicate whether there has been a calibration offsets due to corrosion, deposition or long term drift. When this test is applied to the 7845/6/7 instruments, their temperature coefficient has a significant effect and must be considered (typically 0.3ms/°C and 0.7ms/°C for the E.G. units).

Reconnect the meter to the pipeline if serviceable or remove it for further servicing.

Liquid Density Check

1. Sample Method

If it is necessary to verify the calibration using liquid at operating conditions, then the following sample methods are recommended:

a) FOR STABLE LIQUIDS:

(

Draw off a sample of the liquid into a suitable container, at the same time noting the indicated density, temperature and pressure of the liquid.

Measure the density of the sample under defined laboratory conditions, using a hydrometer or other suitable instrument.

Refer the density measurement under laboratory conditions to that under the line operating conditions of temperature and pressure.

Compare the referred density figure with that indicated by the density meter.

Note: It is essential that a good understanding of the physical properties (temperature coefficient, etc.) of the liquid is acquired when using this method.

Page 6-8

7835/45/46/47 Technical Manual Calibration and Performance

b) FOR UNSTABLE LIQUIDS:

(

Couple a pressure pyknometer and its associated pipework to the pipeline so that a sample of the liquid flows through it.

When equilibrium conditions are reached, the meter density reading is noted as the pyknometer is isolated from the sample flow.

Remove the pyknometer for weighing to establish the product density.

Compare the pyknometer registered density with that obtained from the meter.

Sampling Techniques

Sampling should comply with the international sampling standards (ISO 3171, ASTM D 4177, API 8.2 and IP 6.2). For further details of these procedures, reference should be made to:

Institute of Petroleum: Petroleum Measurement Manual

Part VII Section 1 - Method IP 160 (Hydrometer Method)

(BS2000-160, ISO3675, ASTM 1298)

Institute of Petroleum: Petroleum Measurement Manual

Part VII Section 2 - Continuous Density Measurement

American Petroleum Institute: Manual of Petroleum Measurement Standards

Chapter 14 - Natural Gas Fluids - Section 6:

Installing and proving density meters used to measure hydrocarbon liquid with

densities between 0.3 and 0.7gm/cc at 15.56°C (60°F) and saturation vapour pressure, 1991.

2. Second Density Meter

(a) Connect the second density meter to the pipeline adjacent to meter being checked so that it receives the same

sample of fluid under the same conditions of temperature and pressure as the meter under test.

(

b) Connect the second meter to its readout equipment, switch on and allow both systems to reach equilibrium

conditions.

(

c) Compare the two readings, making any necessary corrections.

It is often the practice, especially in fiscal metering applications, to use two or more density meters in a continuous measurement mode as a means of improving the integrity of the measurement system. Any unacceptable discrepancies between the measurements can immediately raise the necessary alarm signals.

This method of automatic checking has proved to be a very successful technique and where there is a facility for two instruments, the practice of exchanging one for a newly calibrated instrument is proving successful. This is sometimes referred to as the "Substitution Method".

It is very important when using one instrument to verify the performance of a second and similar instrument, to ensure there are no unaccounted for systematic errors which would are not highlighted.

Page 6-9

Calibration and Performance 7835/45/46/47 Technical Manual

6.4 Performance

7835/45/46/47 meters are generally calibrated using specified fluids at 20°C and 1 bar absolute. When operating at other conditions it is necessary to increase the uncertainty of measurement by the magnitude of the offsets if no corrections are applied, or increase by a fraction of the offsets if corrections are applied.

As a general guide, Table 6.1 lists the sources and magnitudes of the offsets affecting the meters covered in this manual, with an example given in Table 6.2.

Table 6.1: Source and Magnitude of Measurement Offsets

Error Source 7835 7845/46/47 7845/47 E.G.

A Primary Standard

B Transfer Standard

C Instrument Accuracy

(at calibration conditions)

D Temperature (uncorrected)

Temperature (corrected)

E Pressure (uncorr’d at 50bar)

Pressure (uncorr’d at 100bar)

Pressure (corrected)

F Velocity of Sound (uncorr’d)

Velocity of Sound (corrected)

G Long term stability

0.05 kg/m

0.1 kg/m

0.15 kg/m

± 0.02 kg/m

0.005 kg/m3/deg C

0.05 kg/m3 0.05 kg/m

0.1 kg/m3 0.1 kg/m

0.35 kg/m

/deg C

-1 to +2 kg/m

+7 to +15 kg/m

0.003 kg/m3/bar

See Section 6.2

20% of offset

0.15 kg/m

/year 0.35 kg/m3/year 1.0 kg/m3/year

+0.9 kg/m

± 0.05 kg/m

0 to +8 kg/m

0.006 kg/m3/bar

/deg C

1.0 kg/m

+1.2 kg/m

± 0.5 kg/m

-40 to +40 kg/m

See Section 6.2

20% of offset

/deg C

For total operational accuracy, the square root of the sum of the squares of each error source (C to G) is recommended, i.e.

Effective Total =

For example, if we consider instruments operating at 50

°C (122°F) and 50 bar, six months after calibration and with no

22222

GFEDC ++++

VOS offset, the total operational accuracy after corrections have been applied is derived as follows:

Table 6.2: Total Operational Accuracy for Example Quoted

Error Source 7835 7845/46/47

0.15 0.35

0.15 1.50

0.15 0.30

- -

0.07 0.175

Effective Total 0.27 1.58

For better accuracy, it would be necessary to carry out an on-line calibration at the operating conditions.

Higher accuracy can be obtained, by request, for all instruments by the use of water calibration or by NAMAS certified laboratory calibration of selected fluids.

Note:

The tables above relate to the effect of uncertainties on the time period output of the meter, and do not take into account any uncertainty in the measurement of the time period itself.

For example, the Advanced Electronics, in calculating the density from the time period, adds some uncertainty to the density measurement. In addition, if the density is output as a 4-20mA signal, there will be a further inaccuracy due to the conversion process. Both these additional uncertainties are quantified in Appendix D.

Page 6-10

7835/45/46/47 Technical Manual Remote Display and Digital Communications

Chapter 7

Remote Display and

Digital Communications

7.1 Introduction

The Advanced Baseboard provides an RS485 digital communications link which can be used to communicate, using RTU Modbus communications protocol, with either a 7965 Remote Display or computer device up to 1000 metres from the meter. (Only one controlling device is permitted on the RS485 link at any one time.) It provides a convenient means for configuring the Baseboard and for displaying or logging measurement data.

7965 DISPLAY

987.7 K /m

777.0 K /m

123.400

21.3 °

LineD BaseD S.G. Tem

Figure 7.1

The RS485 link will support multi-drop installations where, for example, one Remote Display can communicate with several Advanced units at the same time.

Page 7-1

Remote Display and Digital Communications 7835/45/46/47 Technical Manual

7.2 Mechanical Installation of the 7965 Remote Display

The 7965 Remote Display is suitable for handheld or wall-mounted operation, and is designed for use in both safe and hazardous areas.

Caution: Take care not to scratch the transparent front screen.

To install the 7965 Remote Display, the front display section must be separated from its backplate. First, gently prise off both cover plates by using a small screwdriver inserted into a slot at the corner of the cover. This reveals the four clamping screws that hold the front section to the backplate; undo these and separate the two parts.

Cover plates

7965 DISPLAY

Slots for removing cover

Clamping screws

plates

Figure 7.2

The display may be wall mounted by first screwing the backplate to the wall through the holes spaced as shown below, and then screwing the main enclosure to the back plate with the clamping screws.

146

7965 DISPLAY

Page 7-2

Figure 7.3

7835/45/46/47 Technical Manual Remote Display and Digital Communications

7.3 Safe Area Electrical installation

Electrical installation of the Remote Display in a safe area is shown in Chapter 3. The maximum resistance on the power lines between the Baseboard and the Remote Display is 60Ω, which equates to a maximum cable length of 750 metres (2500 ft) for a cable of dc resistance 40Ω/km (12Ω/ 1000ft). If the Remote Display is to be operated at distances of up to 1000 metres from the meter, it should be powered locally with a supply in the range 8 to 28 volts.

7.4 Hazardous Area Electrical installation

When installing in hazardous areas, contact the factory for wiring information. Please also refer to ATEX safety instruction booklet 79655010/SI for information on safety matters.

7.5 Configuring the Baseboard using the Remote Display

On either side of the liquid crystal display there are four press-keys, each of which corresponds to one of the four lines of text. These keys are used for entering data and for navigating the menu.

7965 DISPLAY

LineD 987.7 Kg/m BaseD 777.0 Kg/m S.G. 123.400 ° Temp 21.3 °

3 3

Figure 7.4

For security purposes, a connector, located within the enclosure, can be set to disable the keypad so that the Remote Display simply displays measurement data. For additional security, password control may be used to restrict access to certain areas of the menu structure.

7.5.1 Power-up

Once the electrical installation is completed, the meter and display can be powered-up. The Remote Display undergoes a sequence of self-checks and should then give a display similar to the one above. If not, it will produce the screen shown below which indicates that communication between the meter and display has not been established.

7965 DISPLAY

No devices replying

< Enter demo mode > < Try again > < Change setup >

Figure 7.5

Page 7-3

Remote Display and Digital Communications 7835/45/46/47 Technical Manual

↓

Failure to establish communications is normally due to incorrect electrical installation or incorrect meter slave address (see below).

7.5.2 Slave address

Each meter is given a Modbus slave address. The factory default slave address is 1 (one). By entering the [Change setup] section of the display menu, the Remote Display can be configured to communicate with any valid slave address

(i.e. in the range 1 to 247), or to poll all slave addresses in any given range.

If more than one meter is connected to a single display then each meter should be given a different slave address (see Section 7.7). If the slave address has to be changed, it is recommended that the lowest unused slave address be used.

7.5.3 Demo mode

The demo or demonstration mode allows the user to explore the Display menu structure without a meter attached.

7.5.4 Navigating the menu structure

Access to the menu structure is obtained by pressing any of the 8 keys either side of the display, giving the following menu-screen:

7965 DISPLAY

Process variables Outputs Transducer setup

Figure 7.6

Corresponding to each line of text, there are two keys, one either side of the display. Unless indicated otherwise, the keys on either side of the display perform the same function.

Over 100 separate menu screens are provided. However, after a few minutes of familiarisation, the user should find it simple to navigate through the entire menu.

Page 7-4

7835/45/46/47 Technical Manual Remote Display and Digital Communications

solartron

7965 DISPLAY

LineD 987.7 kg/ BaseD 967.4 kg/m S.G. 98.00

Made in the U.K. by Solartron, Farnborough, Hampshire, England.

solartron

7965 DISPLAY

Diagnostics Service

Made in the U.K. by Solartron, Farnborough, Hampshire, England.

Set Referral Matrix Local setup

Made in the U.K. by Solartron, Farnborough, Hampshire, England.

solartron

7965 DISPLAY

solartron

Process variables Outputs Transducer setup

Made in the U.K. by Solartron, Farnborough, Hampshire, England.

solartron

7965 DISPLAY

^ Pressure Communications

Made in the U.K. by Solartron, Farnborough, Hampshire, England.

7965 DISPLAY

Figure 7.7

The menu structure can be thought of as being cyclic, so that, that by repeatedly pressing the downward arrows (↓), the user will eventually end up back at the first screen.

Some menu items lead to another level of menus, which are also cyclic. In some cases, there are several levels of menus. The simplest way of getting to know these levels is to experiment.

If required, the Remote Display can be reset by pressing the four corner keys together and holding them down for about 2 seconds. When this is done, the Remote Display will re-establish communication with the meter and will bring back the front menu page displaying measurement data, from which the menu structure can be accessed once again.

Page 7-5

Remote Display and Digital Communications 7835/45/46/47 Technical Manual

7.5.5 Menu Structure

The tables below represent some of the top-level menu screens.

Menu-screen 1 at Level 1

Process variables

Outputs

Meter setup

↓

Menu-screen 2 at Level 1

↑

Pressure

Communications

↓

Menu-screen 3 at Level 1

↑

Set referral matrix

Local setup

↓

Menu-screen 4 at Level 1

↑

Diagnostics

Service

Finish

(See Level 2 “Process Variables” menu below)

→

(See Level 2 “Outputs” menu below)

→

Set slave address, view meter serial no. etc.

→

Line pressure, atmospheric pressure, pressure units

→

Set device addresses, poll network again

→

Temperature points, referral temperature, referral points

→

(See “Local Setup” menu below)

→

(See “Diagnostics” menu below)

→

For service engineers only

→

Return to live display

→

Process Variables (PV) Menu (Level 2)

PV Menu-screen 1

Line density units

Base density units

Temperature units

↓

PV Menu-screen 2

↑

P.V. averaging

Set special function

↓

PV Menu-screen 3

↑

Density offset

Temperature offset

< Exit variables >

→ → →

→ →

Page 7-6

Set line density units to kg/m³, lb/gal etc.

Set base density units to kg/m³, lb/gal etc.

Set temperature units to °C or °F.

Select special function

Select process variable averaging (1s, 2s, 5s etc.)

Set density offset factor

Set temperature offset factor

7835/45/46/47 Technical Manual Remote Display and Digital Communications

Outputs Menu (Level 2)

Outputs Menu-screen 1

Analogue output 1

Analogue output 2

Set variable, 4mA and 20 mA points for Output 1

→

Set variable, 4mA and 20 mA points for Output 2

→

↓

Outputs Menu-screen 2

↑

Pulse (freq / alarm)

Alarm settings

Set pulse output to be alarm status or tube frequency

→

Set alarm state, coverage and hysteresis

→

< Exit outputs >

Local Setup Menu (Level 2)

LS Menu-screen 1

Menu language

Screen contrast

System warnings

Select menu language (currently only English)

→

Set screen contrast

→

Turn system warnings on and off

→

↓

LS Menu-screen 2

↑

S/W Version

View display unit details

→

Set device addresses, poll network again

→

< Exit local setup >

Diagnostics Menu (Level 2)

Diagnostics Menu-screen 1

Pickup level

Q of resonance

↓

Diagnostics Menu-screen 2

↑

Tube period

PRT resistance

↓

Diagnostics Menu-screen 3

↑

Change fixed values

Fix meter readings

Enter values for density etc. to use when fixing readings

→

Fix density and temperature readings to set values

→

< Exit diagnostics >

Page 7-7

Remote Display and Digital Communications 7835/45/46/47 Technical Manual

7.6 Multi-drop installation

For a multi-drop installation each meter is allocated a different slave address and linked together in parallel as shown below. Each meter must be individually programmed with its unique slave address using the PC or remote display before they are linked together. Up to 24 meters can be connected in such an arrangement, depending on the cable parameters.

Please note that the arrangement shown below is NOT

7965 DISPLAY

A B

Figure 7.8: RS485 Multidrop arrangement

suitable for hazardous area installations.

+ Pwr

-Pwr

Note that the meters must be given different slave addresses before

they are connected together in a multidrop

arrangement, otherwise there will be communications conflicts between the meters.

The Remote Display communicates with one meter at a time; to obtain information from several meters the Remote Display must be set, each time, to interrogate the individual meters.

Page 7-8

7835/45/46/47 Technical Manual Remote Display and Digital Communications

7.7 Electrical installation of Computer Devices

Electrical installation of computer devices having an RS485 serial port is the same as for a Remote Display, except that the power lines are not required.

When installing in hazardous areas, a safety barrier or galvanic isolator must the RS232/RS485 converter and the meter – contact the factory for wiring information. Please also refer to ATEX safety instruction booklet 79655010/SI for information on safety matters.

Personal Computers (PCs) with an RS232 serial port can readily communicate with the Baseboard using a line powered RS232-to-RS485 converter, as shown below.

RS232

RS232 to RS485

CONVERTER

Figure 7.7: Advanced system linked to a personal computer

In order for a computer device to communicate with an Advanced unit, a software program is required to generate and interpret Modbus messages. The information provided in Appendix H is intended to enable users to write their own Modbus software. For information on using ADView software, please see Chapter 9.

RS485

be interposed between

7.7.1 Connections using an RS232/485 Converter

Terminals 11 and 12 on the Advanced unit’s Baseboard are for RS485 (Modbus) connections to the converter, as shown in Figure 7.8. Note: The PC and converter are always located in a non-hazardous (safe) area.

Converters are available from a number of sources, and can range from simple in-line devices that simply plug into a PC’s RS232 port, to programmable devices with full isolation between the two networks.

The Advanced unit uses a half-duplex implementation of RS485, such that the A and B signals are used for data transmission in both directions. This requires that the RTS line is toggled to indicate the transmission direction; it can be done by the host computer, or automatically by an RS485/232 converter which has the facility to do so. If you are using Windows NT, 2000 or XP on your PC, you should use a converter which automatically changes RTS (as detailed below) otherwise the link may not work correctly.

The optional ADView software kit includes a K3 RS485/RS232 converter that is manufactured by KK Systems Ltd.

The K3 converter derives its power from the PC’s RS232 port RTS or DTR line, which must be held permanently in the high state. This is normally adequate for short distances where there are only a few devices on the network. However, the ability of the port to supply sufficient power is not guaranteed, especially for laptop PCs, and it may be necessary to connect an external power supply. This may also be necessary if using Windows NT, 2000 or XP.

To check the voltage levels, measure the voltages on the RTS input (pin 7) and the DTR input (pin 4) while the converter is connected to the PC (or other RS232 device). This procedure needs a break-out box (not supplied).

Whichever input is powering the converter must have at least +6V during communications. Where the power is found to be insufficient, a 9V dc supply can be plugged into the option DC Input socket (Figure 7.9). See also the manufacturer’s technical information for details.

Page 7-9

Remote Display and Digital Communications 7835/45/46/47 Technical Manual

3 45

PL2

78 9101112

PC (+Adview)

S 2 3 2

RS232/RS485

Converter

R S

4 8 5

2 (B)

1 (A)

(Non-hazardous Area)

If you encounter communication difficulties with RS485, swap over the ‘A’ and

‘B’ signal connections at one end of the network.

Figure 7.8: RS485 connections < 50 metres

9V dc

Power

Supply

RS232/RS485

Converter

(Non-hazardous Area)

Figure 7.9: Powering the converter with an external 9V dc supply

Page 7-10

7835/45/46/47 Technical Manual Remote Display and Digital Communications

For permanent installations, and where the network length is more than 100 metres or so, use the DIN-rail mounted

device KD485-ADE from KK Systems Ltd.

The KD485-ADE is three-way isolated, providing isolation between the two ports and the power supply. It requires a +7 to +35V power supply and typically takes 1 to 2W; (power consumption is largely independent of supply voltage). It is capable of working with Windows 98, NT, 2000 and XP. For a PC running Windows NT/2000/XP, the RTS connection can be omitted.

PL2

DB9

(1-9)

78 9101112

PC (+Adview)

7423

DB25

(1-25)

KD485-ADE

(RTS)

5732

(7 - 35Vdc)

RS232/RS485

Converter

871356

4 3216

(Non-hazardous Area)

Figure 7.10: Modbus connections > 100 metres

The default configuration of the KD485-ADE has Port 2 configured for 9600 baud. The meter uses the following parameter settings, which are not selectable:

Baud rate: 9600 Bits: 8 Parity: None Stop bits: 2

KD485-ADE

RS232 to RS485 Interface Converter/Isolator

Port 1

RS232

RTS In

Port 1 GND

Power Input

Port 1 GND

RxB

RxA

TxB

TxA

Switch

Port 2

RS485

Figure 7.11: Switches on KD485-ADE

The switch on the KD485-ADE should be set with SW1 On (to enable half-duplex operation on Port 2), with the other three switches (SW2, SW3, SW4) set to Off.

Note: In most systems, the ground (GND) connection on pin 6 of port 2 will be unnecessary.

Page 7-11

Remote Display and Digital Communications 7835/45/46/47 Technical Manual

Page 7-12

7835/45/46/47 Technical Manual General Maintenance

Chapter 8

General Maintenance

8.1 General

The 7835/45/6/7 Liquid Density Meters and the 7845/47 Entrained Gas Liquid Density Meters have no moving parts, which reduces the maintenance requirement to simple visual checks for leaks and physical damage.

Check calibrations should be carried out at specified intervals in order to highlight any malfunction or deterioration in meter performance. If a fault or a drop in meter performance is discovered, further tests are required to identify the cause of the fault. Remedial action is limited to cleaning the tube, making good any poor connections and replacing the maintaining amplifier, the temperature probe or, in extreme cases, the entire instrument.

Caution: Extreme care is required in the handling of the meter during transit, its installation into the pipeline and its removal from the pipeline.

8.2 Fault Analysis

Faults generally fall into two main categories - erratic readings or readings outside limits.

Erratic Readings: Normally caused by the presence of gas bubbles in the flowing liquid. Severe electrical

Readings Outside Limits: Normally caused by deposition and/or corrosion on the resonating tube.

Since an electrical fault could also cause either fault and since examination for deposition or corrosion requires the removal off-line of the meter, it is recommended that the electrical system be checked first.

interference or severe pipeline vibrations can also cause this effect.

8.3 General Maintenance Procedure

This procedure is recommended for any periodic maintenance carried out on the system and forms the basis of any faultfinding task.

8.3.1 Physical Checks

(a) Examine the meter and its mounting bracket, pipe couplings and electrical cables for signs of damage and corrosion.

(b) Check the meter for signs of fluid leakage and the state of the rupture plate.

Notes:

1. Any physical damage to the meter case or mounting brackets may have adverse effects on the meter performance

and a full calibration would be advisable to verify its accuracy.

2. Any oil leakage, apart from that found in the region of the rupture plate, can generally be remedied by servicing. Any

rupture plate leakage requires a meter replacement.

Page 8-1

General Maintenance 7835/45/46/47 Technical Manual

8.3.2 Check Calibration

(a) Carry out a check calibration using methods detailed in Chapter 6.

(b) Compare the results obtained with the current calibration certificate figures to identify any substantial deterioration in

the meter's performance or any malfunction.

Notes:

1. A substantial drop in meter performance is likely due to a build-up of deposition on the vibrating tube, which can be

removed by the application of a suitable solvent. See 'Remedial Servicing' section below.

2. Malfunctions may be the result of electrical/electronic faults in either the meter circuit or the readout equipment. The

readout equipment should be proved before attention is directed to the meter as detailed under 'remedial servicing'.

8.3.3 Remedial Servicing

The required servicing falls into two categories - electrical and mechanical.

1. Electrical Servicing

(a) On Advanced units:

Check the voltage between terminals 7 and 8 is between 10V and 20V.

(b) On Standard units:

Carry out power supply and current consumption tests at the meter terminals. These should give:

• 17mA ±1mA at 15.5V to 33V (7835/45/46/47 Standard units)

• 75mA ±2mA at 15.5V to 33V (7845/47 E.G. units)

Remove the power supply to the meter. If current consumption is suspect, replace the meter amplifier.

Identify the drive coils (terminals 8 and 9 on Advanced units, 7 and 8 on Standard units) and disconnect the drive coil wires from the amplifier. Measure the resistance of the drive coils. This should be:

• 95 ±5 ohms at 20°C (68°F).

Reconnect the drive coil wires to the amplifier.

(c) Identify the pick-up coils (terminals 1 and 2 on Advanced units, 9 and 10 on Standard units) and disconnect the pick-

up coil wires from the amplifier. Measure the resistance of the pick-up coils. This should be:

• 95 ±5 ohms at 20°C (68°F).

Reconnect the pick-up coil wires to the amplifier.

(d) On Advanced Units: With no power to the unit, check the 100Ω Platinum Resistance Thermometer element across terminals 4 and 7. The

value of the element resistance is temperature dependent. For this data - see Appendix H.

On Standard Units: Check the 100Ω Platinum Resistance Thermometer element across the terminals 11 and 12 (ensure terminals 3 to 6

are disconnected). The value of the element resistance is temperature dependent. For this data, see Appendix H. Check for continuity between terminals 11 and 3, and terminals 11 and 4, also from terminals 12 to 5 and 12 to 6.

(e) Carry out an insulation test by removing all the input connections to the amplifier terminals (1 to 2 inclusive on

Advanced units and 1 to 7 inclusive on Standard units) and short circuit the terminals together. Test their insulation resistance to the metal case using a 500V d.c. insulation tester (current limited to 5mA maximum). This resistance must be greater than 2MΩ.

Remove the short circuit and reconnect the input leads, if required.

Page 8-2

7835/45/46/47 Technical Manual General Maintenance

2. Mechanical Servicing

Mechanical servicing comprises mainly of keeping the inner surface of the vibrating tube clear of deposition and corrosion. Deposition may be removed by the use of a suitable solvent. Alternatively, the instrument can be removed from the pipeline and cleaned mechanically. Care is required to prevent damage to the inner surface of the tube during the cleaning.

Caution: Extreme care is required in the handling of the meter during transit, its installation into the pipeline and its removal from the pipeline.

Ensure that the meter is not transported when it contains hazardous fluids. This includes fluids that may have leaked into, and are still contained, within the case.

Page 8-3

General Maintenance 7835/45/46/47 Technical Manual

Page 8-4

7835/45/46/47 Technical Manual

9.1 WHAT IS ADVIEW?

ADView is a software package to:

• Configure our density and viscosity transmitters.

• View and save data from them.

• Check that they are functioning correctly.

ADView is installed on a PC and interacts with the ‘Advanced’ unit through one of the PC’s standard serial (RS-232) ports. The PC must be running one of Microsoft’s Windows operating systems: Windows 3.1, 95, 98, NT, 2000 or XP.

Note: To connect to an RS485 (Modbus) device, such as the ‘Advanced’ unit, you will need an RS232/RS485 converter between the PC and the Advanced unit (see Chapter 3 for details).

ADView provides many useful facilities, such as:

• Setting up serial link to communicate with the ‘Advanced’ unit.

• Configuring the ‘Advanced’ unit.

• Displaying data in real time, or as a graph.

• Logging data to a file.

• Verifying correct operation of the system, and diagnosing faults.

• Loading or storing Modbus register values.

• Read/write to individual Modbus registers.

Chapter 9

Using Adview

9.2 INSTALLING ADVIEW

Adview software is available for the PC on a variety of media (e.g. CD-ROM) and is freely available to download from the web sites listed on the back page.

Procedure:

1. Identify the media containing the installation files for ADView.

2. Insert the media into an appropriate drive on your PC.

3. If the installation program does not begin automatically, run the set-up ‘.exe’ file that is on the media. (Note:

This does vary between different PC operating systems. In general, open the File Manager or Windows Explorer, browse the drive containing the media and double-click on the set-up ‘.exe’.)

4. When the installation program starts, you will be asked to supply your name and organisation name for

registration purposes, and supply a directory path into which ADView’s files can be loaded (a default directory path will be suggested).

5. Follow the installation instructions until installation is complete. It will normally only take a few minutes.

You can abandon the installation if you need to do so.

Page 9-1

Using Adview 7835/45/46/47 Technical Manual

9.3 STARTING ADVIEW

Start the Adview software by navigating through the Start Menu to the program entry of Adview 6. Leftclick on it once and the window shown below will then appear.

Note: Developments in ADView may mean that the screen shots differ slightly from

the ones you will see on your PC screen.

Each of the six icons gives you access to the various facilities of ADView. You can choose to connect a Modbus device to one of the PC’s serial ports, or you can use ADView’s built-in simulation of the ‘Advanced’ unit.

To run the simulation, choose Options -> Simulate board response from the menu bar and choose the ‘78235/45/46/47 Densitometer’ option. Then, click on the OK buttons, as necessary, to return to the main Adview screen. When simulation is chosen, ADView ignores the serial port and supplies simulated data. However, you do still need to click on the Communications Setup button followed by the Connect button. Then, click on the

OK buttons, as necessary, to return to the main Adview screen.

9.3.1 Setting up Serial Communications

To operate with a real Modbus device, you will need to connect it to a suitable power supply (see the technical manual for the device) and need a connection to a serial port on the PC. Full details for connecting to the Modbus (RS-485) link on the ‘Advanced’ unit are in Chapter 3.

ADView automatically configures the selected port with the correct settings for the device. For 7829 this is 9k6 baud, 8 data bits, no parity, 1 stop bit, Xon/Xoff (software) flow control.

Note for Windows NT users

An interesting feature of Windows NT is that it does not allow the RTS line to be toggled directly; any attempt to do so will result in a crash or other problem. Unfortunately, some RS485/232 converters require RTS to be toggled. To overcome this difficulty, ADView reads the OS environment variable to determine whether the operating system is Windows NT, 2000 or XP. If it is Windows NT, 2000 or XP, ADView does not toggle RTS, and you will need to use an RS232/485 adapter (Chapter 3) that automatically switches the data direction without using RTS.

Page 9-2

7835/45/46/47 Technical Manual Using Adview

To set the OS variable, click on the Start button, then choose Settings - Control Panel. Click on the System icon, and select the Environment tab. A list of environment variables and their values is shown. If OS does not appear in the list, type ‘OS’ (no speech marks) in the Variable text box, and ‘Windows_NT’ (no speech marks or spaces) in the Value box.

To check whether the link is working, you can use ADView’s auto-detect facility. Select the correct PC port, and then click on the Connect button in the Communications dialogue box. ADView will set the port communications parameters, and then attempt to establish contact with any Modbus devices connected to the serial link, within the address limits set in the dialogue box.

When it finds a device, the message box below appears:

If no active device is found, a warning message is given:

In this case, check that the device is powered up correctly, that the cables and adapter are pushed fully home, and that the communications settings on the device and selected serial port are the same.

Page 9-3

Using Adview 7835/45/46/47 Technical Manual

9.4 USING ADVIEW

9.4.1 ADView facilities

The main ADView window gives access to the various facilities available. A brief description of each is listed below. Using the facilities is largely intuitive so that you can quickly learn the system.

Communications Setup (see section 9.3.1.) Sets up and checks RS-232/RS-485 communications.

Board Configuration (See section 9.4.4.) Enables you to select the measured parameter and range for the analogue output, and to configure density referral by entering matrix values or K factors, as well as special calculations, line pressure and averaging time. Displays instantaneous values of a selectable output parameter and the analogue output.

Data logging (See section 9.4.5.) Provides tabular data from transmitters of line and base density, temperature and special function. One parameter can be displayed as a graph. Data can also be logged to a file in either Excel (tab delimited) or Notepad (space delimited) formats. The frequency at which results are logged can be set, and logging can be started and stopped.

Page 9-4

Diagnostics

Enables you to view:

- live sensor readings

- the status of the meter

- values of working coefficients You can also verify calculations.

Meter details

Shows a list of details such as type, serial number, calibration dates, software version, etc.

With this facility you can dump the contents of all (or selected) Modbus registers from the device, or alternatively transmit values to them. File format is selectable (Excel/tab delimited, or Notepad/Space delimited).

7835/45/46/47 Technical Manual Using Adview

9.4.2 Menu bar

File

Tools

Options

Window

Help

Exit Exit ADView program.

Health Check Determines whether the system is functioning correctly.

Direct Comms. Enables you to specify exactly what will be transmitted on the

Engineer Status Only used by authorised service engineers.

Simulate board response/ Actual Board

Enable / disable screensaver

Provides a means of opening or selecting ADView’s facilities.

About ADView Displays software version number.

9.4.3 Configuring a slave address

The ‘Advanced’ unit factory configuration sets the slave address to 1. However, in many applications it will be necessary to allocate another address. In a multi-drop application, where several Modbus devices are connected on the same network, it is essential to configure unique slave addresses for each device.

(see section 9.4.7)

Serial link (see Appendix C).

Allows you to select between these two options

Allows you to select between these two options. When enabled, the screensaver operates as configured by the Windows system settings.

To do this, you will need to run ADView and use the Register Read/Write facility, detailed in section 9.4.7. Check the value in Register 30 (Modbus Slave Address). If it is not the required value, enter the desired value and click on the write button. The ‘Advanced’ unit will now be configured with the new slave address.

9.4.4 Board configuration

The ‘Advanced’ unit configuration controls the way in which the transmitter will process and present data, user settings, calibration constants and other factors. This data is stored in non-volatile memory known as registers; a full list of the registers used in the ‘Advanced’ unit is given in Appendix H.

To configure the ‘Advanced’ unit, it is necessary to write data into the configuration registers using the RS485/Modbus link. ADView provides a convenient and graphical way of doing this without you needing to know about register addresses and data formats.

Certain parameters are not available for configuration by ADView, including the Density Offset value which may be required to fine tune the calibration of the transmitter (see Chapter 5). However, ADView does have tools for reading and writing to individual Modbus registers (using the Tools -> Register Read/Write facility), and for direct communication on the Modbus (using Tools -> Direct Comms). More details and examples are given in Appendix C, but for the significant majority of applications these tools will not be required.

The factory-installed default configuration is listed in Appendix A (Specification).

Page 9-5

Using Adview 7835/45/46/47 Technical Manual

WARNING: There is no facility within ADView or the ‘Advanced’ unit to ‘reset’ the transmitter to a default configuration. Therefore, before attempting any alterations to the configuration, you are strongly advised to use the Register Dump/Load facility in ADView to store the existing configuration (see section 9.4.5). Then, if any mishap occurs, you will be able to restore the configuration from the saved file.

ADView’s Board Configuration window is shown below:

Shows which unit is being configured.

Enter values of variable to give 4mA and 20mA span of Analogue output 1.

Select a variable to control the 4-20mA Analog Output 1.

The calculated parameters (special functions) available depend on whether Matrix or API referral is selected.

Select referral type, then click on ‘Configure…’ to configure the referral (see text below for more details).

Select configuration of Pulse Output.

Click on ‘Configure...’ to configure the alarm options.

To exit from any of the configuration windows without making any changes, press the Escape key on your computer.

Analog Output 2.

Select a variable to control the 4-20mA Analog Output 1.

Select units for variable controlling Analog Output 2.

Enter line pressure value here.

Select from 1s to 100s, or no averaging.

Click on ‘Configure...’ to select and configure Special Function (calculated parameter). See text below for more details.

Page 9-6

Density Referral (Configure… button)

To configure the density referral calculation, you will need to enter the relevant information. For matrix referral, this is a set of four values of density for each of up to five different temperatures; Appendix B gives more details on this. For API referral, you can select the product type, which automatically adjusts the coefficients of the General Density Equation (see Section 5), or enter your own values.

Special Function (Configure… button)

The range of special functions (calculated parameters) that are available depends on the referral type selected.

7835/45/46/47 Technical Manual Using Adview

Special Function API referral Matrix referral

Specific Gravity

API°

% mass

% volume

° Baumé

° Brix

User defined quadratic

None

When you select the Special Function you require, the configuration window will alter to allow you to input the relevant parameters, if applicable. Note that you can only select one Special Function to be available at any one time.

When you are satisfied with the configuration, you should save it to a file, using the Register Dump/Load facility, as a safeguard against subsequent loss or alteration.

9 9

Page 9-7

Using Adview 7835/45/46/47 Technical Manual

9.4.5 Data logging

ADView’s Data Logging function is a useful tool for checking setups and performing experimental data capture. The diagram below explains some of the features.

Graphical representation of analogue outputs.

Use this button to start logging.

Use this button to stop logging

This button - which is activated when logging has been stopped enables you to configure the frequency of logging, where the logged data will be filed, and the format of the data.

Use this button to select the transmitter and parameter to be displayed on the graph

For selecting the

arameter to be

logged.

Use this button to configure and display graph

Select analogue output of another transmitter.

Tabular display of instantaneous output of transmitter.

For multi-drop configurations (see section 3.4.4), the output of up to three transmitters can be displayed simultaneously.

Use this button to close Data Logging window

Page 9-8

7835/45/46/47 Technical Manual Using Adview

(

9.4.6 Register DUMP/LOAD

This facility is essential for saving the configuration of your ‘Advanced’ unit. You should use it to save the current configuration before you start to alter it, in order to restore it if things go wrong for any reason. Also, if you send the transmitter away for servicing or re-calibration, you should save the current configuration. Details are given below.

Address of unit bein

accessed

Choose data delimiter

Dump onl

Restore a previously saved set of register

Enter desired filename for Dump, or required

Choose which sets of registers to save to file, or simply save all of them.

You can also specify individual

Store the selected

Page 9-9

Using Adview 7835/45/46/47 Technical Manual

9.4.7 Register Read/write

In a few cases, it may be useful to write directly to a single Modbus register. Two likely occasions for using this feature are to set the Slave Address of the unit and to configure a density offset. Appendix H has a complete list of the ‘Advanced’ unit’s registers.

Warning: Before making any changes to individual registers, you should save the current configuration

to a file (section 9.4.5) to safeguard your configuration if anything goes wrong.

From ADView’s menu bar, select Tools -> Register Read/Write.

Click here to see complete list of Modbus register numbers and descriptors.

Choose the one you want to access.

The current register number a

ears here.

For non-numerical values, click here to see complete list of possible entries and select one to write into the register.

Enter numerical values directly.

This button causes the current value of the chosen register

This button causes the current value to be written to the selected register.

You can read and write to any number of registers.

When you have done all you

Page 9-10

7835/45/46/47 Technical Manual 7835 Specification

Appendix A

7835 Specification

This Appendix describes the performance and the mechanical design of the various versions of 7835 Liquid Density Meters. The flange/coupling variations do not affect the meter performance.

A.1 Performance

Density Range: 0 to 3 g/cc (0 to 3000 kg/m

Accuracy: ± 0.00015 g/cc (± 0.15 kg/m

± 0.0001 g/cc (± 0.1 kg/m3) when option selected for calibration in water.

(With the Advanced electronics, there are additional uncertainties attributable to the time period measurement and 4-20mA output.)

Repeatability: ± 0.00002 g/cc (± 0.02 kg/m

Stability: ± 0.00015 g/cc (± 0.15 kg/m

)

) as standard, over range 300 - 1100 kg/m

)

) per year

Temperature Range: -58°F to +230°F (-50°C to +110°C)

Temperature Coefficient: Uncompensated at 850kg/m

Pressure Range: 2175psi (0 to 150 bar), or as defined by flanges

Pressure Coefficient: Uncompensated (See Figure 6.1 in Chapter 6)

(The temperature and pressure coefficients for each instrument are as specified by the instrument calibration certificate.)

Test Pressure: 1.5 x maximum operating pressure

Temperature Sensor

• Technology: 100 ohm PRT (4 wire)

• Range: -328°F to +572°F (-200°C to +300°C)

• Accuracy: BS 1904 Class, DIN 43760 Class A.

A.2 Mechanical

± 0.00002 g/cc (± 0.02 kg/m3/°C) typical

Compensated ± 0.000005 g/cc/°C (± 0.005 kg/m

Compensated ± 0.000003 g/cc/bar (± 0.003 kg/m

(± 0.0003 g/cc/100°F)

(± 0.0002 g/cc/100psi)

/°C)

/bar)

Material: Wetted parts - Ni-Span C and 316L Stainless Steel.

Case finish - 316 Stainless Steel or Hastelloy

Weight: 48lb (22Kg)

Dimensions: (See Figure A.1.)

Page A-1

7835 Specification 7835/45/46/47 Technical Manual

The 7835 is primarily intended for use with hydrocarbon products but may also be used with other process liquids, if they are compatible with the NI-SPAN-C material. The typical composition of NI-SPAN-C is:

Iron: .....…....49.19% Nickel: ..........42.00% Chromium: ....5.00% Titanium: ....…...2.50%

Manganese: ..0.40% Silicon: .......... 0.40% Aluminium: ....0.40% Phosphorus: .....0.40%

Sulphur: ........0.04% Carbon: ......... 0.03%

A.3 The 7835 Meter Versions

There are various versions of the 7835 meter; each is allocated an alphabetic suffix to identify the type of flange/coupling fitted. The installation drawing gives details of the meter’s dimensions and weight with standard electronics (Figure A.1), and with advanced electronics (Figure A.2). Figure A.3 shows the general outline of a flange with the differing dimensions for each flange type tabulated. The meter variations available are:

Meter Version Flange/Coupling Type

7835A*********

7835B*********

7835D*********

7835E*********

7835F*********

7835H*********

7835J*********

7835L*********

1” ANSI 900 RF

1” ANSI 600 RF

1” ANSI 600 RTJ

1” ANSI 900 RTJ

1” ANSI 600 RF Smooth Face

25mm DIN 2635 DN25/PN40

25mm DIN 2635/2512 GVD DN25/PN40

25mm DIN 2637 RF DN25/PN100

A.4 Safety Approvals

A.4.1 ATEX Intrinsically Safe

7835 Standard Electronics: Certification to EN50014 and EN50020

ATEX II1G, EEx ia IIC T6 (-40°C ≤ Ta ≤ +40°C) (7835****AJ****)

T4 (-40°C ≤ Ta ≤ +70°C) (7835****AJ****)

7835 Advanced Electronics: Certification to EN50014 and EN50020 ATEX II1G, EEx ia IIB T4 (-40°C ≤ Ta ≤ +60°C) (7835****DJ****)

ATEX II1G, EEx ia IIC T4 (-40°C ≤ Ta ≤ +60°C) (7835****BJ****)

If the HART

7965 Remote Display: Certification to EN50014 and EN 50020 ATEX II 1 G, EEx ia IIC, T4 (-40°C  Ta  +60°C)

Refer to the ATEX safety instruction booklet (78355015/SI, 78355038/SI or 78355065/SI) for safety matters. Always check the label on the meter for approval(s). Contact the factory for the certified system drawings.

A.4.2 CSA Intrinsically Safe

Certification to CSA C22-2 No 142, CSA C22-2 No 175, UL 508 and UL 913 for use in Canada and USA

7835 Standard electronics: Class I, Division 1 Groups C & D, T3C (7835****AL****)

7835 Advanced electronics and 7965 Remote Display: Class I, Division 1, Groups A, B, C & D, T4 (Single 7835) (7835****BL****)

Class I, Division 1, Groups C & D, T4 (Hart Multi-drop) (7835****DL****)

Certified system drawings are in Appendix K; they are supplied for planning purposes only. Contact the factory for the latest certified system drawings. Always check the label on the meter for approval(s).

option PCB is fitted, certification is limited to the IIB approval.

Page A-2

7835/45/46/47 Technical Manual 7835 Specification

Figure A.1: Installation Drawing for 7835/45/46/47 with Standard Electronics

Page A-3

7835 Specification 7835/45/46/47 Technical Manual

Page A-4

Figure A.2: Installation Drawing for 7835/45/46/47 with Advanced Electronics

7835/45/46/47 Technical Manual 7835 Specification

Figure A.3: Flanges used on the 7835/45/46/47 Liquid Density Meter

Page A-5

7835 Specification 7835/45/46/47 Technical Manual

Page A-6

7835/45/46/47 Technical Manual 7845/46/47 Specification

Appendix B

7845/46/47 Specification

This Appendix describes the performance and the mechanical design of the various versions of 7845/46/47 Liquid Density Meters including the design of the Remote Amplifier option.

The performance of all of the designs is the same and is summarised below. Please refer to Appendix C for the specification of the 7845/47 Entrained Gas Meters.

B.1 Performance

Density Range: 0 to 3000 kg/m

Accuracy: 0.35 kg/m3 (over the range 600 - 1200 kg/m3)

0.5 kg/m

0.1 kg/m

(With the Advanced electronics, there are additional uncertainties attributable to the time period measurement and 4-20mA output.)

Repeatability: 0.05 kg/m

Stability: 0.35 kg/m3 per year

Temperature Range: -50°C (122°F) to +160°C (320°F).

Above 110°C (230°F) the amplifier must be mounted externally.

Temperature Coefficient: Uncompensated at 850 kg/m

Compensated 0.05 kg/m

Pressure Range: 0 to 100 bar (1450psi) for 7845

0 to 50 bar (725psi) for 7846 or flange limit 0 to 20 bar (290psi) for 7847

Pressure Coefficient: Uncompensated (see Figure 6.2)

Compensated 0.006 kg/m

(The temperature and pressure coefficients for each instrument are as specified by the instrument calibration certificate.)

(over the range 300 - 1600 kg/m3)

with calibration in water

0.9 kg/m3/°C typical

1.2 kg/m

/°C maximum

/°C

/bar

Test Pressure: 1.5 x maximum operating pressure

Temperature Sensor

• Technology: 100Ω PRT (4 wire)

• Range: -200°C (-328°F) to 300°C (572°F)

• Accuracy: BS 1904 Class, DIN 43760 Class A

Page B-1

7845/46/47 Specification 7835/45/46/47 Technical Manual

B.2 Mechanical

Material:

7845 7846 7847

Wetted Parts 316L S.S. or Hastelloy® Hastelloy® C22® 316L Stainless Steel

Case Finish 316L Stainless Steel 316L Stainless Steel 316L Stainless Steel

Dimensions and Weight: (See Figure A.1.)

B.3 7845/46/47 Meter Versions

There are various versions of the 7845/46/47 meters; each is allocated an alphabetic suffix to identify the type of flange/coupling fitted. The installation drawings (Figures A.1 and A.2) give details of the meter’s dimensions and weight. Figure A.3 shows a general outline of a flange with the differing dimensions for each flange type tabulated. Figure B.1 gives details of various couplings available for 7847.

The meter variations available are:

Meter Version Flange/Coupling Type

7845C*********

7845H*********

7845J*********

7845K*********

7845L*********

1 inch ANSI 300 RF

25mm DIN 2635 DN25/PN40

25mm DIN 2635/2512 GVD DN25/PN40

1 inch ANSI 600 RF

25mm DIN 2637 RF DN25/PN100

7846C*********

7846H*********

7846J*********

7847C*********

7847H*********

7847P*********

7847R*********

7847S*********

1 inch ANSI 300 RF

25mm DIN 2635 DN25/PN40

DIN 2635/2512 GVD DN25/PN40

1 inch ANSI 300 RF

25mm DIN 2635 DN25/PN40

COUPLING 1 inch TRI-CLAMP

COUPLING 25mm ISO 2853

COUPLING 25mm DIN 11851

Page B-2

7835/45/46/47 Technical Manual 7845/46/47 Specification

1.0 inch coupling

25mm ISO coupling

25mm DIN coupling

Figure B.1: Couplings: 1.0 inch, 25mm ISO and 25mm DIN used on 7847 Version.

Page B-3

7845/46/47 Specification 7835/45/46/47 Technical Manual

B.3.1 7845/46/47 and 7845/47 Entrained Gas Meters with Remote Amplifier

For operating in product temperatures greater than 110°C (230°F), it is necessary to remove the amplifier unit from direct contact with the meter to a remote position. For this purpose, a flexible PTFE conduit with over-braiding of stainless steel mesh is introduced between the amplifier housing and the new amplifier housing. Three twisted pair cable looms are fed through the conduit to complete the extended meter/amplifier connections.

This high temperature arrangement allows the amplifier unit to be mounted in a more temperate environment and in no way impairs the operational accuracy of the meter.

The maintenance and calibration procedures remain relevant to the re-configured meter assembly. Figure B.2 shows the installation for the 78452 version, which is for Advanced Electronics only.

B.4 Safety Approvals

B.4.1 ATEX Intrinsically Safe

7845/46/47 Standard Electronics: Certification to EN50014 and EN50020

ATEX II1G, EEx ia IIC T6 (-40°C ≤ Ta ≤ +40°C)

T4 (-40°C ≤ Ta ≤ +70°C)

7845/46/47 Advanced Electronics: Certification to EN50014 and EN50020 ATEX II1G, EEx ia IIB T4 (-40°C ≤ Ta ≤ +60°C) [784****(D/F)J***** version] ATEX II1G, EEx ia IIC T4 (-40°C ≤ Ta ≤ +60°C) [784****(B/H)J***** version]

If the HART option PCB is fitted, certification is limited to the IIB approval.

7965 Remote Display: Certification to EN50014 and EN 50020

ATEX II 1 G, EEx ia IIC, T4 (-40°C  Ta  +60°C)

B.4.2 CSA Intrinsically Safe

Certification to CSA C22-2 No 142, CSA C22-2 No 175, UL 508 and UL 913 for use in Canada and USA

7845/46/47 Standard electronics: Class I, Division 1 Groups C & D, T3C

7845/46/47 Advanced electronics and 7965 Remote Display: Class I, Division 1, Groups A, B, C & D, T4 (Single instrument)

Class I, Division 1, Groups C & D, T4 (Hart Multi-drop)

Page B-4

7835/45/46/47 Technical Manual 7845/46/47 Specification

Note: For part number and hazardous area rating, see Chapter 1.

Figure B.2: 7845 Meter with Advanced Electronics Remote Amplifier Unit

Page B-5

7845/46/47 Specification 7835/45/46/47 Technical Manual

Page B-6

7835/45/46/47 Technical Manual 7845/47 Entrained Gas Specification

Appendix C

7845/47 Entrained Gas Specification

Appendix C describes the performance and the mechanical design of the various versions of 7845/47 Entrained Gas Meters. Mechanically, they are the same as the Standard 7845/47 Liquid Density Meters, but they operate at a lower vibration frequency which is more appropriate for measuring liquids with entrained gas, and as a consequence have a different performance specification.

C.1 Performance

Density Range: 0 to 3 g/cc (0 to 3000 kg/m3)

Accuracy: ± 0.005 g/cc (± 5.0 kg/m

(With Advanced Electronics, there are additional uncertainties attributable to the time period measurement and 4-20mA output.)

% Entrained Gas: 0% to 100% by volume

Repeatability: ± 0.001 g/cc (± 1.0 kg/m

Stability: ± 0.001 g/cc (± 1.0 kg/m

Temperature Range: (-58°F to +320°F (-50°C to +160°C)

At above 230°F (110°C), the amplifier must be mounted externally.

Temperature Coefficient: Uncompensated at 850kg/m

Compensated ± 0.00005 g/cc/°C (± 0.05 kg/m

) over the range 0 to 1.6 g/cc (0 to 1600kg/m3)

)

) per year

± 0.0012 g/cc/°C (± 1.2kg/m3/°C) typical.

± 0.0015 g/cc/°C (± 1.5kg/m

(± 0.003 g/cc/100°F)

/°C).maximum.

/°C)

290 psi (0 to 20 bar) for 7847.

Pressure Range: 1450 psi (0 to 100 bar) for 7845.

Pressure Coefficient: Uncompensated (see Figure 6.2)

Compensated ± 0.00005 g/cc/bar (± 0.05kg/m

(± 0.003 g/cc/100psi)

(The temperature and pressure coefficients for each instrument are as specified by the instrument calibration certificate.)

Test Pressure: 150 bar (2175psi)

30 bar (435psi) for 7847

Temperature Sensor

• Technology: 100 ohm PRT (4 wire)

• Range: -200°C (-328°F) to 300°C (572°F)

• Accuracy: BS 1904 Class, DIN 43760 Class A.

C.2 Mechanical

Material:

7845 7847

Wetted Parts 316L S.S. or Hastelloy® 316L Stainless Steel

Case Finish 316L Stainless Steel 316L Stainless Steel

Weight: 48lb (22kg)

Dimensions: (See Figure A1.)

/bar)

Page C-1

7845/47 Entrained Gas Specification 7835/45/46/47 Technical Manual

C.3 7845/47 Meter Versions

There are various versions of the 7845/47 Entrained Gas Meters, each allocated an alphabetic suffix to identify the type of flange/coupling fitted. The installation drawing (Figure A.1) gives details of the meter’s dimensions and weight. Figure A.3 shows a general outline of a flange with the differing dimensions for each flange type tabulated. Figure B.1 gives details of various couplings.

The meter variations available are:

Meter Version Flange/Coupling Type

7845C***(E/F/H)******

7845H***(E/F/H)******

7845J***(E/F/H)******

7845K***(E/F/H)******

7845L***(E/F/H)******

7847A***(E/F/H)******

7847C***(E/F/H)******

7847E***(E/F/H)******

7847J***(E/F/H)******

7847K***(E/F/H)******

1 inch ANSI 300 RF

25mm DIN 2635 DN25/PN40

25mm DIN 2635/2512 GVD DN25/PN40

1 inch ANSI 600 RF

25mm DIN 2367 RF DN25/PN100

COUPLING 1 inch TRI-CLAMP

COUPLING 25mm ISO 2853

COUPLING 25mm DIN 11851

1 inch ANSI 300 RF

25mm DIN 2635 DN25/PN40

C.4 Safety Approvals

C.4.1 ATEX Intrinsically Safe

7845/47 Entrained Gas meter with Standard Electronics is NOT intrinsically safe.

7845/47 Entrained Gas meter with Advanced Electronics: Certification to EN50014 and EN50020

ATEX II1G, EEx ia IIB T4 (-40°C ≤ Ta ≤ +60°C) (784x****HJ***** version) ATEX II1G, EEx ia IIC T4 (-40°C ≤ Ta ≤ +60°C) (784x****FJ***** version)

7965 Remote Display: Certification to EN50014 and EN 50020 ATEX II 1 G, EEx ia IIC, T4 (-40°C  Ta  +60°C)

C.4.2 CSA Intrinsically Safe

Certification to CSA C22-2 No 142, CSA C22-2 No 175, UL 508 and UL 913 for use in Canada and USA

7845/46/47 Standard electronics: Class I, Division 1 Groups C & D, T3C

7845/46/47 Advanced electronics and 7965 Remote Display: Class I, Division 1, Groups A, B, C & D, T4 (Single 784x) (784x****FL***** version)

Class I, Division 1, Groups C & D, T4 (Hart Multi-drop) (784x****HL***** version)

Page C-2

7835/45/46/47 Technical Manual Electronics Specifications

Appendix D

Electronics Specifications

D.1 Standard Electronics

Power Supply (all meters):

Safe areas: +16V to +28Vdc Hazardous areas: +24V (nominal)

Minimum voltage at meter: >15.5V

Output Signals: 7835/45/46/47 - two wire 2V across 180Ω 4V across 390Ω.

D.2 Standard Entrained Gas Electronics

Power Supply (all meters):

Safe areas: +16V to +28Vdc

Minimum voltage at meter: >15.5V

Output Signals: 7845/47 E.G. - two wire 2V across 66Ω.

D.3 Advanced Electronics

Power Supply (all meters):

Safe areas: +9.5V to +28V dc, 70 to 80mA Hazardous areas: +24V (nominal)

The minimum voltage at meter must always be >9.5V. As a guide, the table below indicates the maximum line resistance in hazardous areas, using a 24volt supply.

Advanced Electronics

System combination

Baseboard 340

Baseboard + remote display 260

Baseboard + locally powered remote display 280

Baseboard + HART® board 320

Baseboard + HART® board + remote display 250

Maximum line resistance

(barrier + cable)

)

(

Page D-1

Electronics Specifications 7835/45/46/47 Technical Manual

Analogue Outputs (including HART

Power Supply:

Safe areas: +16V to +28Vdc, 25mA Hazardous areas: +28Vdc max.

Accuracy @ 20°C (68°F): ± 0.1% of reading plus 0.05% of full scale (FS).

Repeatability: ± 0.025% of FS.

Out-of-range capability: 2-22mA on 4-20mA (Programmable alarm state)

Accuracy over -40 to +85°C (-40 to 185°F): ± 10 PPM of FS +/- 50 PPM of reading /°C.

Repeatability over -40 to +85°C (-40 to 185°F): ± 0.05% of FS.

Tube Frequency / Alarm Output

Power Supply:

Safe areas +16V to +28V dc, 25mA Hazardous Areas: +28Vdc max.

output)

Nominally 23mA (1kΩ load) Minimum load resistor 500Ω

Temperature Measurement

Accuracy of electronic measurement: ±0.05°C

Time Period Measurement

Accuracy @ 20°C (68°F): ±5ppm Accuracy over 10 to 60°C (50 to 140°F): ±50ppm Accuracy over -40 to 85°C (-40 to 185°F): ±100ppm

Stability 5ppm/year

Remote Display

Power Supply +8V to +28V dc, 15mA

D.4 Environmental Performance

Temperature

Standard electronics Operating: -40 to +85°C (-40 to 185°F) Storage: -40 to +85°C (-40 to 185°F)

Advanced electronics Operating: -40 to +85°C (-40 to 185°F) Storage: -40 to +85°C (-40 to 185°F)

Remote display Operating: 0 to +50°C (32 to 122°F) Storage: -20 to +70°C (-4 to 158°F)

Page D-2

IP Rating

Standard Electronics enclosure IP66

Advanced Electronics enclosure IP66

Remote Display IP65

7835/45/46/47 Technical Manual Baseboard Calculations and Configurable Factors

Appendix E

Baseboard Calculations

and Configurable Factors

This Appendix summarises the many functions available on the Advanced Baseboard and details how they may be used. The contents of this Appendix are:

E.1 Baseboard configuration

E.2 Baseboard diagnostics

E.3 Baseboard calculations

E.1 Baseboard Configuration

This section describes the main factors on the baseboard, which can be configured via the RS485 link. When using a 7965 Remote Display or a PC running proprietary software to configure the baseboard, no additional information is required. If other software is being used, refer to the Modbus register assignment information in Appendix H.

The main parameters that can be reconfigured are:

• Calculated parameters.

• 4-20mA Output variables.

• 4-20mA Output range and alarm limits.

• Measurement units.

• Line pressure value (used for density calculations).

• Signal averaging.

• Pulse output configuration.

For details of the calculated parameters, refer to Section E.4; the other parameters are outlined below. Further configurable factors are available, but it is recommended that they be not changed without first consulting with the factory.

It is useful to record the settings made to a meter. You will find two forms at the end of this Appendix - one each for the General and Fiscal Software versions - which you can use to do this.

4 to 20mA Analog Output variables

The analogue outputs can give any of the calculated variables, as indicated below. The Special functions are discussed in Section E.4

Output Factory default Available settings

Analog 1 Line density

(500 to 1500 kg/m³)

Line density, Base density, Special function or Temperature.

Analog 2 Temperature

(0 to 100°C)

Line density, Base density, Special function or Temperature.

Page E-1

Baseboard Calculations and Configurable Factors 7835/45/46/47 Technical Manual

4-20mA Analog Output ranges

The 4-20mA output ranges can be set to any sensible values. The 4mA setting should always represent a smaller measurement value than the 20mA setting.

4-20 mA Out-of-Range Alarms

The operation of these alarms is dependent on the software issue. To find out the software issue, either use the appropriate Modbus command, or examine the label on the baseboard EPROMS.

Software V1, issue 1.00, 1.01 and 1.02 only

If either of the Analog output parameters go outside the selected range settings, then the outputs will give an out-of-

range alarm signal to alert the user. These out-of-range alarm signals can be set to either 2mA or 22mA using the

jumper connectors on the Baseboard (refer to Figure 3.3b).

The out-of-range alarms trigger if the output signal is outside the range 4mA or 20mA by an amount set by the

output hysteresis. The default hysteresis is 1% of the output parameter, but can be configured to be greater if

required, (see section E.3).

Example

4mA setting = 500kg/m³, 20mA setting = 1000kg/m³, alarm hysteresis = 1%  Out-of-range alarm will trigger if the density falls below 495kg/m³ or rises above 1010kg/m³.

Software V1, issue 1.03 on

The hysteresis facility is not available in these versions of the software. The 4-20mA output signals can actually

span the range 3.9mA to 20.8mA; thus, a signal outside the range 4-20mA is considered an alarm signal. In

addition, if there is a circuit malfunction within the meter, the output will go to either 2mA or 22mA, in accordance

with the setting of the alarm jumper setting.

Measurement Units

Parameter Factory default Available settings

Density units kg/m³ kg/m³, g/cc, lb/ft³,lb/gal (US)

Temperature units

°C °C or °F

Pressure units bar bar, Pa, kPa, psi

Signal Averaging

In very noisy situations, it may be desirable to smooth out any short term variations in signals using the Signal Averaging. The available settings are:

no averaging, 1s, 2s, 5s, 10s, 20s, 50s and 100s averaging.

The averaging times are only approximate.

Page E-2

7835/45/46/47 Technical Manual Baseboard Calculations and Configurable Factors

Pressure

Nominal line and atmospheric pressure are set as follows. The values are used in the calculations of liquid density.

Parameter Factory default Available settings

Line Pressure 1.013bar Any value

Atmospheric

1.013 bar Any value

pressure

Pulse Output configuration

This output may be set to give either an alarm signal or the meter tube frequency.

The Alarm may be set to signal any combination of:

• System/circuit malfunction.

• Analog 1 out-of-range alarm.

• Analog 2 out-of-range alarm.

• Any user-defined variable.

The alarm can be set to be ‘normally-on’ or ‘normally-off’.

When set to ‘tube frequency’, the pulse output can be coupled to a signal converter to simulate a standard meter.

Density and Temperature Reading Adjustment

If the density or temperature readings given by the Advanced unit do not coincide with the expected density or temperature readings, the user may feel that it is appropriate to add or subtract density or temperature offsets. Normally these would both be set to zero.

Page E-3

Baseboard Calculations and Configurable Factors 7835/45/46/47 Technical Manual

E.2 Baseboard Diagnostics

This section describes the Baseboard diagnostic functions that may be accessed using a Remote Display or PC communicating with the Baseboard via the RS485 link.

Analog outputs

These can be set to 4mA, 12mA and 20mA to indicate correct operation and calibration.

Alarm output

Correct operation of the alarm can be checked by alternating between the ‘normally-on’ and ‘normally-off’ alarm settings.

Pick-up level

In most applications, the pick-up level should measure 14 ±1 mV. However, if the liquid is very viscous or heavily aerated, the pick up level may be permitted to fall to 2mV but the short-term stability of the signal may be adversely affected.

Time period measurement

The indicated Time Period should agree with the calibration certificate to within 60ns after taking into consideration the difference in ambient conditions.

Q measurement

The Q measurement, as indicated by the Remote Display, should be within ± 20% of the value indicated in the graph below.

10,000

5,000

3,000 2,000

1,000

500

300 200

100

1 10 100 1,000 10,000 100,00

Viscosity cP

Calculation validation

The values of line density, base density and temperature may all be fixed in the diagnostics section of the menu, and so it is possible to check the validity of all calculations.

Page E-4

7835/45/46/47 Technical Manual Baseboard Calculations and Configurable Factors

E.3 Baseboard Calculations

The software on the Advanced Baseboard is available in either the General software version or the Fiscal software version. The two software versions perform different sets of calculations, which are outlined below.

Calculation General software version Fiscal software version

Line density

Base density Matrix referral method, API referral method,

Special function Specific Gravity, Baumé, Brix, % Volume,

Specific Gravity, API Degrees

% Mass, General Quadratic Equation

E.3.1 Base density

As indicated in the table above, Base density - that is, the density of the liquid at a specified reference temperature other than the line temperature - may be calculated by either a Matrix referral method or by the API Referral method.

Matrix density referral.

The Matrix Density Referral method uses a process of interpolation and extrapolation between a matrix of known density and temperature points to determine the liquid density at a reference temperature other than the line temperature. A typical referral matrix is shown below.

TEMPERATURE

D3D

DENSITY

LINE TEMPERATURE t

1D2

TEM PERATURE REFERRE D DENSITY

LINE DENSITY

Figure E.4a: Matrix density referral

The lines D1 to D4 indicate the density of four product types, for which the density is known at five different temperatures.

The information required for the referral may be conveniently entered using the Remote Display or a PC configuration tool, and is summarised below:

• Five referral temperatures, in increasing order

• Twenty density referral points (density at 5 temperatures for each of 4 product types), each of which must be a

non-zero value. If any of the matrix points does contain a zero value then the Matrix Referral calculation is turned off.

• Reference temperature, which may be any one of the five referral temperatures.

Page E-5

Baseboard Calculations and Configurable Factors 7835/45/46/47 Technical Manual

API Density referral

When using the Fiscal software version, an API density referral is always performed. The calculation uses an iterative process to determine the density at a reference temperature and pressure, by applying temperature and pressure corrections using the API-ASTM-IP petroleum measurement tables.

The information required for the API density referral may be conveniently entered using a Remote Display and is summarised as follows:

• Reference pressure and reference temperature.

• Product type: Refined product, crude product or user defined.

Density/Temperature Relationship

Correction factors in the revised API-ASTM-IP petroleum measurement tables are based on the following correlation equations:

/ ρ15 = exp ( -α15Δt ( 1 + 0.8 α15Δt ) )

Where

= Density at line temperature t °C.

= Density at base temperature 15 °C.

Δt = t - 15 °C. α

= Tangent thermal expansion coefficient per degree C at base temperature of 15°C.

The tangent coefficient differs for each of the major groups of hydrocarbons. It is obtained from the following relationship:

ρ+

=α

1510

Where K0 and K1 are API factors.

Hydrocarbon Group Selection

The hydrocarbon group can be selected to be:

(a) General Refined products, (b) General Crude products or (c) User defined.

For General Refined products, the values of K

and K1 are automatically selected as follows according to the corrected

density.

Hydrocarbon

Group

K0 K1 Density Range

(kg/m³)

Gasolines 346.42278 0.43884 654-779

Jet Fuels 594.54180 0.0000 779-839

Fuel Oils 186.9696 0.48618 839-1075

For Crude Oil, the API factors are:

Product K0 K1

Crude oil 613.97226 0.0000

User defined factors can be entered as any sensible value.

Page E-6

7835/45/46/47 Technical Manual Baseboard Calculations and Configurable Factors

Density / Pressure Relationship

Isothermal secant compressibility can be defined by the simplified equation:

=β

Where liquid volume changes from V

to V1 as the gauge pressure changes from zero (atmospheric) to P

And β = Isothermal secant compressibility at temperature t

δV

= Change of volume from V0 to V

P1= Gauge pressure reading (P - 1.013) bars

Hence

P1 β−=

Where

= Corrected density at zero (atmospheric) gauge.

= Uncorrected density.

= P-1.013 where P is pressure in bars (P - base)

A correlation equation has been established for β from the available compressibility data; i.e.,

log

C = -1.62080 + 0.00021592t + 0.87096 x 106(ρ15)-2 + 4.2092t x 103(ρ15)-2 per bar

Where

β = C x 10

Bar

t = Temperature in deg C ρ = ρ

/ 1000 = oil density at 15 °C (kg/litre)

Page E-7

Baseboard Calculations and Configurable Factors 7835/45/46/47 Technical Manual

E.3.2 Special Function Calculations

Specific gravity

Specific gravity (SG) = Base density (@ T

Degrees Baumé

Degrees Baumé = 145 - (145 / Base density)

(Where Base Density is in units of g/cc.)

Degrees Brix

) / Density of water (@ T

ref

)

ref

341.384

Degrees Brix =

−

906.318

¨ ©

· ¨

(Where SG is Specific gravity.)

Quadratic Equation

The following quadratic equation is implemented:

BAy

Where:

A, B, C = user programmable constants. d = density of water (also a programmable constant).

= base density.

% Mass

()()

−ρ

% mass of product A =

2B1

()()

100*

−ρ

21B

Where:

= base density of product A

= base density of product B

= base density of mixture

% Volume

−ρ

% volume of product A =

100*

−

Where:

= base density of product A

= base density of product B

= base density of mixture

1086.66

¸ ¸

Page E-8

API Degrees

5.141

5.131

API −=

Where Base density value, used for specific gravity value (SG), is determined from API density referral.

Micro Motion Liquid Density Meter Standard and Advanced Electronics - Model 7835, 7845, 7846, 7847 Manuals & Guides

Specifications and Main Features

Frequently Asked Questions

User Manual