Rosemount 5081 Explosion-Proof Transmitter Manuals & Guides

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00809-0100-3581, Rev AC

Rosemount™ 5081

Explosion Proof, Single-Input Intelligent Transmitter

Reference Manual

October 2019

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Essential instructions

Read this page before proceeding!

Emerson designs, manufactures, and tests its products to meet many national and international standards. Because these instruments are sophisticated technical products, you must properly install, use, and maintain them to ensure they continue to operate within their normal specifications. The following instructions must be adhered to and integrated into your safety program when installing, using, and maintaining Emerson products. Failure to follow the proper instructions may cause any one of the following situations to occur: loss of life, personal injury, property damage, damage to this instrument, and warranty invalidation.

• Read all instructions prior to installing, operating, and servicing the product.

• If this Reference Manual is not the correct one, call 1-800-854-8257 or 949-757-8500 to request the correct Reference

Manual. Save this Reference Manual for future reference.

• If you do not understand any of the instructions, contact your Emerson representative for clarification.

• Follow all warnings, cautions, and instructions marked on and supplied with the product.

• Inform and educate your personnel in the proper installation, operation, and maintenance of the product.

• Install equipment as specified in the installation instructions of the appropriate Reference Manual and per applicable local and

national codes. Connect all products to the proper electrical and pressure sources.

• To ensure proper performance, use qualified personnel to install, operate, update, program, and maintain the product.

• When replacement parts are required, ensure that qualified people use replacement parts specified by Emerson.

Unauthorized parts and procedures can affect the product's performance, place the safe operation of your process at risk, and VOID YOUR WARRANTY. Look-alike substitutions may result in fire, electrical hazards, or improper operation.

• Ensure that all equipment doors are closed and protective covers are in place, except when maintenance is being performed

by qualified people, to prevent electrical shock and personal injury.

WARNING

Physical access

Unauthorized personnel may potentially cause significant damage to and/or misconfiguration of end users’ equipment. This could be intentional or unintentional and needs to be protected against.

Physical security is an important part of any security program and fundamental to protecting your system. Restrict physical access by unauthorized personnel to protect end users’ assets. This is true for all systems used within the facility.

Notice

ROSEMOUNT (“SELLER”) SHALL NOT BE LIABLE FOR TECHNICAL OR EDITORIAL ERRORS IN THIS MANUAL OR OMISSIONS FROM THIS MANUAL. SELLER MAKES NO WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, WITH RESPECT TO THIS MANUAL AND, IN NO EVENT, SHALL SELLER BE LIABLE FOR ANY SPECIAL OR CONSEQUENTIAL DAMAGES INCLUDING, BUT NOT LIMITED TO, LOSS OF PRODUCTION, LOSS OF PROFITS, ETC.

PRODUCT NAMES USED HEREIN ARE FOR MANUFACTURER OR SUPPLIER IDENTIFICATION ONLY AND MAY BE TRADEMARKS/ REGISTERED TRADEMARKS OF THESE COMPANIES.

THE CONTENTS OF THIS PUBLICATION ARE PRESENTED FOR INFORMATIONAL PURPOSES ONLY, AND WHILE EVERY EFFORT HAS BEEN MADE TO ENSURE THEIR ACCURACY, THEY ARE NOT TO BE CONSTRUED AS WARRANTIES OR GUARANTEES, EXPRESSED OR IMPLIED, REGARDING THE PRODUCTS OR SERVICES DESCRIBED HEREIN OR THEIR USE OR APPLICABILITY. WE RESERVE THE RIGHT TO MODIFY OR IMPROVE THE DESIGNS OR SPECIFICATIONS OF SUCH PRODUCTS AT ANY TIME.

SELLER DOES NOT ASSUME RESPONSIBILITY FOR THE SELECTION, USE, OR MAINTENANCE OF ANY PRODUCT. RESPONSIBILITY FOR PROPER SELECTION, USE, AND MAINTENANCE OF ANY SELLER PRODUCT REMAINS SOLELY WITH THE PURCHASER AND END-USER.

Warranty

LIMITED WARRANTY: Subject to the limitations contained in Section 2 herein and except as otherwise expressly provided

1. herein, Rosemount (“Seller”) warrants that the firmware will execute the programming instructions provided by Seller and that the Goods manufactured or Services provided by Seller will be free from defects in materials or workmanship under normal use and care until the expiration of the applicable warranty period. Goods are warranted for twelve (12) months from the date of initial installation or eighteen (18) months from the date of shipment by Seller, whichever period expires first. Consumables and Services are warranted for a period of 90 days from the date of shipment or completion of the Services. Products purchased by Seller from a third party for resale to Buyer (“Resale Products”) shall carry only the

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warranty extended by the original manufacturer. Buyer agrees that Seller has no liability for Resale Products beyond making a reasonable commercial effort to arrange for procurement and shipping of the Resale Products. If Buyer discovers any warranty defects and notifies Seller thereof in writing during the applicable warranty period, Seller shall, at its option, promptly correct any errors that are found by Seller in the firmware or Services, or repair or replace F.O.B. point of manufacture that portion of the Goods or firmware found by Seller to be defective, or refund the purchase price of the defective portion of the Goods/Services. All replacements or repairs necessitated by inadequate maintenance, normal wear and usage, unsuitable power sources, unsuitable environmental conditions, accident, misuse, improper installation, modification, repair, storage or handling, or any other cause not the fault of Seller are not covered by this limited warranty, and shall be at Buyer's expense. Seller shall not be obligated to pay any costs or charges incurred by Buyer or any other party except as may be agreed upon in writing in advance by an authorized Seller representative. All costs of dismantling, reinstallation and freight, and the time and expenses of Seller's personnel for site travel and diagnosis under this warranty clause shall be borne by Buyer unless accepted in writing by Seller. Goods repaired and parts replaced during the warranty period shall be in warranty for the remainder of the original warranty period or ninety (90) days, whichever is longer. This limited warranty is the only warranty made by Seller and can be amended only in a writing signed by an authorized representative of Seller. Except as otherwise expressly provided in the Agreement, THERE ARE NO REPRESENTATIONS OR WARRANTIES OF ANY KIND, EXPRESSED OR IMPLIED, AS TO MERCHANTABILITY, FITNESS FOR PARTICULAR PURPOSE, OR ANY OTHER MATTER WITH RESPECT TO ANY OF THE GOODS OR SERVICES. It is understood that corrosion or erosion of materials is not covered by our guarantee.

LIMITATION OF REMEDY AND LIABILITY: SELLER SHALL NOT BE LIABLE FOR DAMAGES CAUSED BY DELAY IN

2. PERFORMANCE. THE SOLE AND EXCLUSIVE REMEDY FOR BREACH OF WARRANTY HEREUNDER SHALL BE LIMITED TO REPAIR, CORRECTION, REPLACEMENT, OR REFUND OF PURCHASE PRICE UNDER THE LIMITED WARRANTY CLAUSE IN SECTION 1 HEREIN. IN NO EVENT, REGARDLESS OF THE FORM OF THE CLAIM OR CAUSE OF ACTION (WHETHER BASED IN CONTRACT, INFRINGEMENT, NEGLIGENCE, STRICT LIABILITY, OTHER TORT, OR OTHERWISE), SHALL SELLER'S LIABILITY TO BUYER AND/OR ITS CUSTOMERS EXCEED THE PRICE TO BUYER OF THE SPECIFIC GOODS MANUFACTURED OR SERVICES PROVIDED BY SELLER GIVING RISE TO THE CLAIM OR CAUSE OF ACTION. BUYER AGREES THAT IN NO EVENT SHALL SELLER'S LIABILITY TO BUYER AND/OR ITS CUSTOMERS EXTEND TO INCLUDE INCIDENTAL, CONSEQUENTIAL OR PUNITIVE DAMAGES. THE TERM “CONSEQUENTIAL DAMAGES” SHALL INCLUDE, BUT NOT BE LIMITED TO, LOSS OF ANTICIPATED PROFITS, LOSS OF USE, LOSS OF REVENUE, AND COST OF CAPITAL.

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Reference Manual Contents

00809-0100-3581 October 2019

Chapter 1 Start-up......................................................................................................................... 7

Chapter 2 Description and specifications........................................................................................9

2.1 Features and applications................................................................................................................. 9

2.2 General specifications.......................................................................................................................9

2.3 Rosemount 5081 - (A/P/C/T) product certifications........................................................................ 12

2.4 Functional specifications................................................................................................................ 15

2.5 Ordering information..................................................................................................................... 17

Chapter 3 Install...........................................................................................................................19

3.1 Unpack and inspect........................................................................................................................ 19

3.2 Installation guidelines.....................................................................................................................19

3.3 Orient the display board................................................................................................................. 20

3.4 Mount on a flat surface................................................................................................................... 21

3.5 Mount on a pipe............................................................................................................................. 22

Chapter 4 Wire............................................................................................................................ 25

4.1 Wiring overview............................................................................................................................. 25

4.2 Power supply/current loop............................................................................................................. 25

Chapter 5 Display and operate..................................................................................................... 29

5.1 User interface and main display...................................................................................................... 29

5.2 Infrared remote control (IRC)..........................................................................................................30

5.3 Menu system..................................................................................................................................31

Chapter 6 Programming basics.................................................................................................... 43

6.1 Programming................................................................................................................................. 43

6.2 Test 4-20 mA outputs and current generated during hold and faults.............................................. 43

6.3 Correct temperature...................................................................................................................... 45

6.4 Set up a custom curve (conductivity measurements only).............................................................. 46

6.5 Restore to factory default settings..................................................................................................47

6.6 Set access (security) code...............................................................................................................47

6.7 Activate or deactivate HOLD...........................................................................................................48

Chapter 7 Measurements............................................................................................................. 49

7.1 Calibrating pH sensors....................................................................................................................49

7.2 Calibrating oxidation reduction potential (ORP) sensors.................................................................52

7.3 Calibrating contacting and toroidal conductivity sensors................................................................54

7.4 Calibrating dissolved oxygen, ozone, free chlorine, total chlorine, and ozone sensors.................... 56

Chapter 8 Diagnostics and troubleshooting..................................................................................61

8.1 Warning and fault messages...........................................................................................................61

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Contents Reference Manual

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8.2 pH/ORP diagnostics and troubleshooting.......................................................................................62

8.3 Contacting and toroidal conductivity diagnostics and troubleshooting.......................................... 89

8.4 Chlorine, dissolved oxygen, and ozone diagnostics.......................................................................100

8.5 Chlorine, dissolved oxygen, and ozone troubleshooting...............................................................103

8.6 Factory assistance and repairs...................................................................................................... 129

Chapter 9 Digital communications............................................................................................. 131

9.1 HART® communications...............................................................................................................131

9.2 FOUNDATION™ Fieldbus communication..........................................................................................132

9.3 Asset Management Solutions....................................................................................................... 134

Chapter 10 Return of material...................................................................................................... 137

10.1 General information................................................................................................................... 137

10.2 Warranty repair.......................................................................................................................... 137

10.3 Non-warranty repair................................................................................................................... 137

Appendix A Engineering Drawings................................................................................................139

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Reference Manual Start-up

00809-0100-3581 October 2019

1 Start-up

Procedure

1. Using the infrared remote control (IRC), press PROG, NEXT, NEXT, and ENTER in this order.

2. Select the measurement type and unit of measurement.

3. Use the arrow keys to toggle between Celsius and Fahrenheit.

4. Press ENTER and then RESET.

5. Press PROG, NEXT, and ENTER in this order.

6. Use the arrow keys to toggle T AUTO between ON or OFF. This determines whether the transmitter uses the process temperature (ON) or a

manual temperature (OFF).

7. Press ENTER.

8. If you select OFF, enter the manual temperature desired using the arrow keys.

9. Press ENTER.

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Start-up Reference Manual

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8 Rosemount 5081

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Reference Manual Description and specifications

00809-0100-3581 October 2019

2 Description and specifications

2.1 Features and applications

The Rosemount™ 5081 includes the following features:

General

The Rosemount 5081 explosion-proof transmitter is a loop powered device with a robust design that serves several industrial, commercial, and municipal applications. It offers a local operator interface (LOI) that can display values from a single measurement input. This transmitter is compatible with a multitude of analytical sensors.

Analytical measurements

• pH/ORP

• Contacting conductivity

• Toroidal conductivity

• Dissolved oxygen

• Ozone

• Chlorine

Maintenance features

• Automatic two-point buffer calibration routine

• Automatic recognition of resistance temperature device (RTD)

• Sensor diagnostics

Diagnostics

Continuous monitoring of sensor performance along with warnings and fault messages to alert the user of failures.

Enclosure

Explosion-proof and corrosion resistant

2.2 General specifications

Table 2-1: General Specifications

Housing Cast aluminum with epoxy coating. NEMA® 4X(IP65) and NEMA7B. Neoprene

O-ring seals.

Dimensions 6.3 x 6.9 x 6.4 in. (160.5 x 175.3 x 161.3 mm) See the engineering drawings in

Engineering Drawings.

Conduit openings ¾-in. female national pipe thread (FNPT)

Ambient temperature -4 to 149 °F (-20 to 65 °C)

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Description and specifications Reference Manual

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Table 2-1: General Specifications (continued)

Storage temperature -22 to 176 °F (-30 to 80 °C)

Relative humidity 0 to 95% (non-condensing)

Weight / shipping weight 10 lb./11 lb. (4.5 kg/5.0 kg)

Display First line: 7 segment LCD, 0.8 in. (20 mm) high. This line shows process

variables (pH/ORP, contacting conductivity, toroidal conductivity, etc.) Second line: 7 segment LCD, 0.3 in. (7 mm) high. This line shows process temperature, output current, warnings, faults, and messages during calibration/programming.

Display board can be rotated 90 degrees clockwise or counterclockwise if desired.

Temperature resolution 0.1 °C

Hazardous location approval For details, see Rosemount 5081 - (A/P/C/T) product certifications.

RFI/EMI Meets all industrial requirements of EN61326.

Diagnostics (may slightly vary based on measurement type)

• Calibration error

• Low temperature error

• High temperature error

• Sensor failure

• Line failure

• CPU failure

• Calibration error

• Zero error

• Temperature slope error

• Sensor failure

• ROM failure

• Input warning

Once one of the above warnings/faults are diagnosed, the LOI will display a message describing the failure detected.

Table 2-2: HART® Digital Communications

Power and load requirements Supply voltage at the transmitter terminals should be at least 12 Vdc. Power

supply voltage should cover the voltage drop on the cable plus the external load resistor required for HART communications (250 Ohms minimum). Minimum power voltage is 12 Vdc. Maximum power voltage is 42.4 Vdc (30 Vdc for intrinsically safe operation). Figure 4-1 shows the supply voltage required to maintain 12 Vdc (upper line) and 30 Vdc (lower line) at the transmitter terminals when the current is 22 mA.

Analog output Two-wire, 4-20 mA output with superimposed HART digital signal, scalable

over the operating range of the sensor.

Output accuracy ±0.05 mA

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Reference Manual Description and specifications

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Table 2-2: HART® Digital Communications (continued)

Variables assignable to • pH

• Temperature

• mV

• Glass impedance

• Reference impedance

• RTD resistance

• Oxidation reduction potential (ORP)

• Conductivity

• Resistivity

• Concentration

• Raw conductivity

• Chlorine

• Dissolved oxygen

• Dissolved ozone

Table 2-3: FOUNDATION™ Fieldbus Digital Communications

Power and load requirements A power supply voltage of 9-32 Vdc at 22 mA is required.

AI blocks assignable to • pH

• Temperature

• mV

• Glass impedance

• Reference impedance

• RTD resistance

• ORP

• Conductivity

• Resistivity

• Concentration

• Raw conductivity

• Chlorine

• Dissolved oxygen

• Dissolved ozone

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Description and specifications Reference Manual

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2.3 Rosemount 5081 - (A/P/C/T) product certifications

Rev 1.0

2.3.1 European Directive Information

A copy of the EU Declaration of Conformity can be found at the end of the Quick Start Guide. The most recent revision of the EU Declaration of Conformity can be found at

Emerson.com/Rosemount.

2.3.2 Ordinary Location Certification

As standard, the Power Module has been examined and tested to determine that the design meets the basic electrical, mechanical, and fire protection requirements by a nationally recognized test laboratory (NRTL) as accredited by the Federal Occupational Safety and Health Administration (OSHA).

2.3.3

2.3.4

Installing equipment in North America

The US National Electrical Code® (NEC) and the Canadian Electrical Code (CEC) permit the use of Division marked equipment in Zones and Zone marked equipment in Divisions. The marking must be suitable for the area classification, gas, and temperature class. This information is clearly defined in the respective codes.

USA

FM hazardous locations

Certificate

Standards

Markings

FM17US0021X

FM Class 3600:2011, FM Class 3610:2015, FM Class 3611:2016 FM Class 3615:2006, FM Class 3810:2005, ANSI/NEMA 250:1991

Intrinsically safe for use in Class I, II, and III, Division 1, Groups A, B, C, D, E, F, and G; T4 Ta = -20 °C to 70 °C; per control drawing numbers 1400676; 1400677

Nonincendive for Class I, Division 2, Groups A, B, C, and D; T4 Ta = -20 °C to 70 °C; per control drawing numbers 1400676; 1400677

Dust-ignitionproof for use in Class II and Class III, Division 1, Groups E, F, and G; T6 Ta = -20 °C to 70 °C;per control drawing number 1400678

Explosionproof for use in Class I, Div 1, Groups B, C, and D; T6 Ta = -20 °C to 70 °C; per control drawing number 1400678

Type 4X

Special Conditions for Safe Use (X):

1. The Rosemount 5081-T conductivity transmitters shall only be used with the Rosemount 222, 225, 226, 228 (1 in. and 2 in. only) and 245 toroidal sensors.

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2.3.5 Canada

CSA hazardous locations

Certificate

Standards

Markings

2.3.6 Europe

Rosemount 5081-A and 5081-P liquid transmitters

ATEX

1132747

C22.2 No. 0-M1987, C22.2 No. 25-1966, C22.2 No. 30-M1986 C22.2 No. 94-M91, C22.2 No 142-M1987, C22.2 No. 157-92, C22.2 No. 213M1987

Intrinsically safe for Class I Groups A, B, C, and D; Class II Groups E, F, and G; Class III; T4 Tamb = 70 °C, per installation drawing 1400674 and 1400675

Non-incendive for Class I, Div. 2 for Groups A, B, C, and D; Class II, Div. 2, Groups F and G; Class III; T4 Tamb = 70 °C, per installation drawing 1400674 and 1400675 (Rosemount 5081-A/P/C/T) and per 1700462 (Rosemount 5081-T)

Explosion-proof for Class I, Groups B, C, and D; Class II, Groups E, F, and G, Class III, T6 Tamb = 70 °C

Type 4X

Certificate

Standards

Markings

Special Conditions for Safe Use (X):

1. The Rosemount 5081 enclosure may be made of aluminum alloy and given a protective polyurethane paint finish; however, care should be taken to protect it from impact or abrasion of located in a zone 0.

BAS02ATEX1284X

EN 60079-0:2012+A11:2013 EN 60079-11:2012

II 1 G Ex ia IIC T4 Ga (-20 °C ≤ Ta ≤ +65 °C)

Rosemount 5081-C liquid transmitter

ATEX

Certificate

Standards

Baseefa03ATEX0099X

EN 60079-0:2012+A11:2013 EN 60079-11:2012

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Description and specifications Reference Manual

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Markings

Special Conditions for Safe Use (X):

1. The equipment enclosure may contain light metals. The equipment must be installed in such a manner as to minimize the risk of impact or friction with other metal surfaces.

II 1 G Ex ia IIC T4 Ga (-20 °C ≤ Ta ≤ +65 °C)

Rosemount 5081-T liquid transmitter

ATEX

Certificate

Standards

Markings

Special Conditions for Safe Use (X):

Baseefa03ATEX0399X

EN 60079-0:2012+A11:2013 EN 60079-11:2012

II 1 G Ex ia IIC T4 Ga (-20 °C ≤ Ta ≤ +65°C)

2.3.7

1. The equipment may contain light metals. The equipment must be installed in such a manner as to minimize the risk or impact or friction with other metal surfaces.

International

IECEx

Certificate

Standards

Markings

Special Conditions for Safe Use (X):

IECEx BAS 09.0159X

IEC 60079-0:2011 IEC 60079-11:2011

Ex ia IIC T4 Ga (-20 °C ≤ Ta ≤ +65°C)

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Reference Manual Description and specifications

00809-0100-3581 October 2019

2.4 Functional specifications

The sections below display the specifications for measuring different substances with the Rosemount 5081.

2.4.1 pH/ORP specifications

pH range 0 to 14

ORP range -1400 to +1400 mV

Calibration/standardization The automatic buffer recognition uses stored buffer values and

their temperature curves for the most common buffer standards available worldwide. The transmitter also performs a stabilization check on the sensor in each buffer. To make a manual two-point calibration, immerse the sensor in two different buffer solutions and enter the pH values. The microprocessor automatically calculates the slope which is used for self-diagnostics. The transmitter displays an error message if the pH sensor is faulty. The operator can read the slope on the display and/or manually adjust it if desired. To complete an on-line, one-point standardization process, enter the pH or ORP value of a grab sample as measured by a lab reference.

Preamplifier location Use a preamplifier to convert the high impedance pH electrode

signal to a low impedance signal for transmitter use. Use the transmitter's integral preamplifier when the sensor to transmitter distance is less than 15 ft. (4.5 m). Use a sensor with a built-in preamplifier or a junction box if distance is longer than 15 ft. (4.5 m).

Automatic temperature compensation

Accuracy ±01 mv at 77 °F (25 °C) ± 0.01 pH

Repeatability ±01 mv at 77 °F (25 °C) ±0.01 pH

Stability 0.25% / year at 77 °F (25 °C)

External 3 or 4 wire Pt 100 resistance temperature device (RTD) or Pt 1000 RTD, located in the sensor, compensates the pH reading for temperature fluctuations. Compensation covers the range 5 to 270 °F (-15 to 130 °C). The operator may also select manual temperature compensation.

2.4.2 Contacting conductivity specifications

Measured range 0-20,000 µS/cm

Calibration To calibrate, immerse the sensor in a known solution and enter its value or

enter the cell constant for ultra-pure applications.

Automatic temperature compensation 3-wire Pt 100 or Pt 1000 resistance temperature device (RTD)

Conductivity: 32 to 392 °F (0 to 200 °C) Resistivity: 32 to 212 °F (0 to 100 °C) Low conductivity: 32 to 212 °F (0 to 100 °C)

Accuracy ± 0.5% of reading and ±0.001 µS/cm

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Description and specifications Reference Manual

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Repeatability ± 0.25% of reading

Stability 0.25% of output range/month, non-cumulative

Ambient temperature coefficient ± 0.05% of reading/°C

Temperature slope adjustment 0 to 5%/°C

Other temperature compensation algorithms

Compatible RTD 100 Ohm or 1000 Ohm with automatic recognition

Ultra-pure water compensation Cation conductivity

Raw (uncompensated) conductivity

2.4.3 Toroidal conductivity specifications

Measured range 50 to 2,000,000 µS/cm

Calibration To calibrate, immerse the sensor in a known solution and enter its value.

Automatic temperature compensation 3-wire Pt 100 resistance temperature device (RTD)

Conductivity: 32 to 392 °F (0 to 200 °C) % concentration: 32 to 212 °F (0 to 100 °C)

Accuracy ±1.0% of reading

Repeatability ±0.25% of reading

Stability 0.25% of output range/month, non-cumulative

Ambient temperature coefficient ±0.2% of FS/°C

Temperature slope adjustment 0 to 5% / °C

% concentration ranges Sodium hydroxide: 0 to 15%

Hydrochloric acid: 0 to 16% Sulfuric acid: 0 to 25% and 96 to 99.7%

2.4.4 Dissolved oxygen specifications

Measurement range 0 - 99 ppm (mg/L), 0 - 200 saturation

Resolution 0.01 ppm, 0.1 ppb for Rosemount 499ATrDO sensor

Temperature correction for membrane permeability

Calibration Air calibration (user must enter barometric pressure) or calibration against a

Automatic between 32 and 122 °F (0 and 50 °C). Can be disabled.

standard instrument

2.4.5 Free chlorine specifications

Measurement range 0-20 ppm (mg/L) as Cl

Resolution 0.001 ppm (auto-ranges at 0.999 to 1.00 and 9.99 to 10.0)

Temperature correction for membrane permeability

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Automatic between 32 and 122 °F (0 and 50 °C). Can be disabled.

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Reference Manual Description and specifications

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pH correction Automatic between pH 6.0 and 9.5. Manual pH correction is also available.

Calibration Calibrate against grab sample with portable test kit.

2.4.6 Total chlorine specifications

Measurement range 0-20 ppm (mg/L) as Cl

Resolution 0.001 ppm (auto-ranges at 0.999 to 1.00 and 9.99 to 10.0)

Temperature correction for membrane permeability

Calibration Calibrate against grab sample with portable test kit.

Automatic between 41 and 95 °F (5 and 35 °C). Can be disabled.

2.4.7 Ozone specifications

Measurement range 0-10 ppm (mg/L)

Resolution 0.001 ppm (auto-ranges at 0.999 to 1.00 and 9.99 to 10.0)

Temperature correction for membrane permeability

Calibration Against grab sample analyzed using portable test kit.

Automatic between 41 and 95 °F (5 and 35 °C). Can be disabled.

2.4.8 Percent oxygen in gas

Measurement range 0 - 25% oxygen

Resolution 0.1% - TBD

Calibration Air calibration (automatic measurement of barometric pressure with internal

pressure sensor)

Sample pressure 0 to 50 psig

Sample temperature 32 to 110 °F (0 to 43 °C)

2.5 Ordering information

The Rosemount 5081 two-wire transmitter is intended for the determination of pH/ORP, conductivity (both contacting and toroidal), and for measurements using membranecovered amperometric sensors (oxygen, ozone, and chlorine). For free chlorine measurements, which often require continuous pH correction, a second input for a pH sensor is available. Use a hand-held infrared remote controller to locally configure and calibrate the transmitter.

Rosemount 5081

Option Description

P pH/ORP

C Contacting conductivity

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Smart two-wire microprocessor transmitter

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Description and specifications Reference Manual

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T Toroidal conductivity

A Amperometric (oxygen, ozone, and chlorine)

Option Description

HT Analog 4-20 mA output with superimposed HART® digital signal

FF FOUNDATION™ Fieldbus digital output

FI FOUNDATION Fieldbus digital input with FISCO

Option Description

20 Infrared remote controller included

21 Infrared remote controller not included

Option Description

60 No approval

67 FM approved intrinsically safe, non-incendive (when used with

appropriate sensor and safety barrier), and explosion-proof

69 CSA approved intrinsically safe, non-incendive (when used with

appropriate sensor and safety barrier), and explosion-proof

73 ATEX/IECEx approved intriniscally safe (when used with

appropriate sensor and safety barrier)

Example 5081-P-HT-20-67

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Reference Manual

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Install

3 Install

3.1 Unpack and inspect

To unpack the instrument:

Procedure

1. Inspect the shipping container(s). If there is damage, contact the shipper immediately for instructions.

2. If there is no apparent damage, unpack the container(s).

3. Ensure that all items shown on the packing list are present. If items are missing, contact your local Customer Care representative

4. Save the shipping container and packaging. They can be used to return the instrument to the factory in case of damage.

3.2 Installation guidelines

1. The transmitter tolerates harsh environments. For best results, install the transmitter in an area where temperature extremes, vibrations, and electromagnetic and radio frequency interference are minimized or absent.

2. To prevent unintentional exposure of the transmitter circuitry to the plant environment, keep the security lock in place over the circuit end cap. To remove the circuit end cap, loosen the lock nut until the tab disengages from the cap end and then unscrew the cover.

3. The transmitter has two ¾-in. conduit openings, one on each side of the housing. Run sensor cable through the left side opening (as viewed from the wiring terminal end of the transmitter) and run power wiring through the right side opening.

4. Use water tight cable glands to keep moisture out of the transmitter.

5. If using conduit, plug and seal the connections at the transmitter housing to prevent moisture from getting inside the transmitter.

CAUTION

Equipment damage

Moisture accumulating in the transmitter housing can affect the performance of the transmitter and may void the warranty.

6. If the transmitter is installed some distance from the sensor, a remote junction box with preamplifier in the junction box or in the sensor may be necessary. Consult the sensor reference manual for maximum cable lengths.

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3.3 Orient the display board

The display board can be rotated 90 degrees, clockwise or counterclockwise, from the original position. To reposition the display:

Procedure

1. Loosen the cover lock nut until the tab disengages from the circuit end cap. Unscrew the cap.

2. Remove the three bolts holding the circuit board stack.

3. Lift and rotate the display board 90 degrees, clockwise or counterclockwise, into the desired position.

4. Position the display board on the stand offs. Replace and tighten the bolts.

5. Replace the circuit end cap.

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3.4 Mount on a flat surface

Figure 3-1: Mounting Transmitter on a Flat Surface

A. Cover lock B. Threaded cap (two places) C. Terminal block (TB). Terminal end cap omitted for clarity this view.

D. ¼-in. - 20 threads (four places)

E. Surface plate (by others)

F. O-ring (two places) G. Circuit end H. Terminal end

I. Flat surface mounting pad hole pattern

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Install

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Reference Manual

3.5 Mount on a pipe

Use pipe mounting kit (23820-00 or 23820-01).

Figure 3-2: Mounting Transmitter on a Pipe

A. Over look B. Terminal block C. Kit, 2-in. pipe/wall mounting bracket

Order PN2002577 as a separate item.

D. ½ - 20 threads

E. ¼ - 20 screw

Screws furnished with mounting kit only. Not furnished with transmitter.

F. 1½-in. to 2-in. pipe (customer furnished) G. U-bolt

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Reference Manual Install

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H. 5/16 washer

I. 6/18 - 18 nut J. ¾ - 14 FNPT (two places)

K. 2-in. pipe supplied by customer

L. ¾ - 14 NPT (two places)

M. Threaded cap, two places

N. Circuit end O. Terminal end

P. Terminal end cap omitted for clarity this view Q. Four mounting holes

R. Bottom view

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Wire

4 Wire

4.1 Wiring overview

To find wiring diagrams for specific sensors, check the wiring sections of the reference manuals for those particular sensors.

4.2 Power supply/current loop

4.2.1 Power supply overview

The tables below display the minimum and maximum voltages needed to operate the transmitter.

Minimum supply voltage at the transmitter terminals

Minimum power supply for load resister 250 Ohms

Maximum power supply voltage 42.0 Vdc

Maximum power supply voltage for intrinsically safe installations

Figure 4-1: Power Supply Voltage for HART® or without HART Communication Configurations

12.0 Vdc

30.0 Vdc

A. With HART communication B. Without HART communication

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Table 4-1: Values from Graph

Upper line Power supply voltage needed to provide 12 Vdc

at the transmitter terminals for a 22 mA current

Lower line Power supply voltage needed to provide 30 Vdc

for a 22 mA current

Maximum current About 24 mA

Minimum load for digital communications 250 Ohms

Minimum power supply voltage to supply the

12.0 Vdc lift off voltage at the transmitter

17.5 Vdc

4.2.2 Wire to HART® or FOUNDATION™ Fieldbus communication protocol

Procedure

1. Run the power/signal wiring through the opening nearest terminals 15 and 16.

2. Use shielded cable and ground the shield to the power supply.

3. To ground the transmitter, attach the shield to the grounding screw on the inside of the transmitter case.

You can also use a third wire to connect the transmitter to earth ground.

Note

For optimum EMI/RFI immunity, shield the power supply and enclose it in an earth ground metal conduit. Do not run power supply/signal wiring in the same conduit or cable tray with AC power lines or with relay actuated signal cables. Keep power supply/signal wiring at least 6 ft. (2 m) away from heavy electrical equipment. An additional 0-1 mA current loop is available between TB-14 and TB-15. A 1 mA current in this loop signifies a sensor fault. See Figure 4-2 for wiring instructions. See

Diagnostics and troubleshooting for more information about sensor faults.

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Figure 4-2: General Wiring Architecture

A. Filter B. Terminators C. Trunk

D. Spur

The power supply, filter, first terminator, and configuration device are typically located in the control room.

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5 Display and operate

5.1 User interface and main display

The following are examples of the main (process) display screen (Figure 5-1) and the program display screen (Figure 5-2).

Figure 5-1: Main Display Screen

A. Conductivity value B. Temperature in °C or °F

Figure 5-2: Program Display Screen

A. Indicates HART® or FOUNDATION™ Fieldbus digital communiciations B. Conductivity value C. Units of display

D. Active menu: CALIBRATE, PROGRAM, or DIAGNOSE

E. Sub-menus, prompts, and diagnostic messages appear here.

F. Available commands for sub-menus, prompts, or diagnostic messages G. Appears when transmitter is in hold H. Appears when a disabling condition has occurred

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5.2 Infrared remote control (IRC)

Use the IRC to read diagnostics messages, calibrate connected sensors, and program the transmitter. Hold the IRC within 6 ft. (1.8 m) of the transmitter and less than 15 degrees from the horizontal of the display window.

Figure 5-3: Infrared Remote Control (IRC) Functions

1. RESET

• End current operation and

return to the main display.

• Changes are not saved.

• Does not return the

transmitter to factory default settings.

2. Editing (arrow) keys

• Change values of a flashing

display.

• Left and right arrows move

the cursor by one digit.

• Up and down arrows increase

or decrease the values and navigate through the display options.

3. CAL

• Access to Calibration menu.

4. PROG

• Access to Program menu.

5. DIAG

• Access to diagnostics.

6. HOLD

• Access to turn hold readings

on or off.

7. ENTER

• Advance to the next prompt.

• Store selected item.

• Store value in memory.

8. NEXT

• Advance to the next sub-

menu.

9. EXIT

• End current operation.

• Return to the first prompt in

the present sub-menu.

• Changes are not saved.

Guidelines for using IRC

• Do not use harsh chemicals or abrasive brushes when cleaning the remote control.

• If the green LED does not light when you press a key, the issue is probably a weak

battery. To restore operation, remove four screws to access and replace the two batteries. Observe the two warning messages posted at the rear of the remote control.

• Requires two 1.5 V AAA batteries. If used in hazardous areas, replacement batteries

must be Energizer E92/EN92 or Duracell MN2400/PC2400.

• All functions for remote control PN 24479-00 are the same as those for the previous

remote control, PN 23572-00.

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5.3 Menu system

There are three main menus: Calibrate, Program, and Diagnose. Calibrate and Program menus have additional sub-menus as shown in the figures below.

Table 5-1: Program Menu

Displayed item Definition

OUtpUt Current output menu header

4MA 4 mA current output (setpoint)

20MA 20 mA current output (setpoint)

HoLd Current output on hold

FAULt Fault condition current output setting

dPn Current output dampening time

tESt Current output test value

tAUtO Automatic temperature compensation

tMAn Manual temperature compensation

dISPLAY Display menu header

tYP Measurement type

tEMP ° C/° F toggle selection

OUtPUt Current (mA) or percent of full scale display

COdE Access code

OFFSt Offset value

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7.00

CALIBRATE

PROGRAM DIAGNOSE

CALIbrAtE Std tEMP AdJ OUtPUt CAL

CAL bF1

bF 1

bF1 4.01

CAL bF2

bF2

bF2 10.01

Std 7.00

SLOPE 59.01

tEMP 25.0 Cur 4.00

Cur 20.00

OutPut dIAGnOStiC tEMP dISPLAY

HArt bUFFEr

ISOPOtnAL

LinE FrEq

PAMP=trAnS dEFAULt

4 MA 00.00

20 MA 14.00

HoLd 21.00

FAULt 22.00

dPn 0.00

tESt 12.00

ROFFSt

000

dIAG OFF

iMpiC ON

GFH 1500

GWH 1000

GWL 020

GFL 010

CAL 000

rEF LO

rFH 140

rWH 040

rWL 000

rFL 000

tAUTO On

tMAN 25.0

tYPE PM

tEMP C

OUtPUt Cur

COdE 000

AddrESS 00

PrEAMp 02

burSt OFF

Id 0

bAUTO On

bUFFEr Gnd

StAbiLiSE

UNE 10

deLtA 00.02

tCOEF 00.00

ISO 07.00

Snr 07.00

LinE 00

FACtOrY

YES

InPut 58.9 SLOPE OFFSt GIMP 1000 rIMP 10 5081-P-Ht SoFt FAULtS

nonE

Sub-menu

PROMPT

Diag Message

HArd

HART pH menu tree

Display and operate Reference Manual

October 2019 00809-0100-3581

pH Menu Tree

Figure 5-4: HART

32 Rosemount 5081

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7.00

CALIBRATE

PROGRAM DIAGNOSE

CALIbrAtE Std tEMP AdJ OUtPUt CAL

CAL bF1

bF 1

bF1 4.01

CAL bF2

bF2

bF2 10.01

Std 7.00

SLOPE 59.01

tEMP 25.0 Cur 4.00

Cur 20.00

OutPut dIAGnOStiC tEMP dISPLAY

HArt bUFFEr

ISOPOtnAL

LinE FrEq

PAMP=trAnS dEFAULt

4 MA 00.00

20 MA 14.00

HoLd 21.00

FAULt 22.00

dPn 0.00

tESt 12.00

ROFFSt 000

dIAG OFF

iMpiC ON

GFH 1500

GWH 1000

GWL 020

GFL 010

CAL 000

rEF LO

rFH 140

rWH 040

rWL 000

rFL 010

tAUTO On

tMAN 25.0

tYPE PH

tEMP C

OUtPUt Cur

COdE 010

AddrESS 00

PrEAMp 02

burSt OFF

Id 0

bAUTO On

bUFFEr Gnd

StAbiLiSE

UNE 10

deLtA 00.02

tCOEF 00.00

ISO 07.00

Snr 07.00

LinE 00

FACtOrY

YES

InPut 58.9 SLOPE OFFSt GIMP 1000 rIMP 10 5081-P-Ht SoFt FAULtS

nonE

Sub-menu

PROMPT

Diag Message

HArd

Reference Manual Display and operate

00809-0100-3581 October 2019

Figure 5-5: HART ORP Menu Tree

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Page 34

5000

µS/cm

25.0C 12.00mA

CAL key PROG key DIAG key HOLD key

Process Display

CALIBRATION

PROGRAM

DIAGNOSTICS

CALIbrAtE

SEnSOr 0

tEMP AdJ

CELL COnSt

tEMP SLOPE

OUtPUt CAL

OutPut

tEMP

dISPLAY

HArt

SEtUP CuST

dEFAULT

AbS C

0 air

CELL COnSt

tSLOPE

CAL F

5081-C-Ht

SoFt

HArd

FaULTs

Process display screen

Mtr CAL

Display and operate Reference Manual

October 2019 00809-0100-3581

Figure 5-6: HART Contacting Conductivity Menu Tree

34 Rosemount 5081

Page 35

5000

µS/cm

25.0C 12.00mA

CAL key PROG key DIAG key HOLD key

Process Display

CALIBRATION

PROGRAM

DIAGNOSTICS

CALIbrAtE

SEnSOr 0

tEMP AdJ

CELL COnSt

tEMP SLOPE

OUtPUt CAL

OutPut

tEMP

dISPLAY

HArt

SEtUP CuST

dEFAULT

AbS C

OFFSt

CELL COnSt

tSLOPE

CAL F

5081-T-Ht

SoFt

HArd

FaULTs

Model 5081T-HT

Process Display Screen

Reference Manual Display and operate

00809-0100-3581 October 2019

Figure 5-7: HART Toroidal Conductivity Menu Tree

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Page 36

MAIN DISPLAY

CALIBRATE PROGRAM DIAGNOSE

sensor 0 sensor Cal temp adj ph Cal

(free chlorine only)

air cal

In process

press 760 Grab spl

Cal 100

only)

(All)

Temp 025.0

auto Cal

Man Cal

std pH

pH slope

Cal bf1

bf1 4.01

Cal bf2

bf2 10.00

Cal bf1

bf1 7.00

Cal bf2

bf2 7.00

std 07.00 Slope 59.16

temp DEFAULT

Cal setup

Line freq

bar press

taUto On

tman 25.0

display

type --

Unit ppm

sensor ADO

Unit ppm

temp C

Output Cur

Code 000

if O

If Cl (free

and total)

If O

FACTORY NO

span Cal 0 Cal

stabilize

limit 00.05

time 10 SlOpe snGl Salnty 00.0

All

if chlorine if O

Line 60

PH ---

Pamp trans

Man 7.00

diaGnostiC

roffst 060

diaG OFF

lmptC On

GFI 1500

GFL 000

pH Cal

baUtO On

bUFFEr Std

StAbILISE

tIME 00

dELtA 0.02

Cl only

if On

if Off

Enter

Unit nnHG

pman 760

type 02

sensor Cur

0 Current

bar press

5081-a-Ht

faUlts

SUB MENU

PROMPT

delta 0.05

sensitivty

OUTPUT

4 MA 00.00

20 MA 10.00

HOLD 21.00

FAULT 22.00

DPN 0.00

TEST 12.00

Unit: ppm

Unit PPRESS

Unit: %

Unit: PPB

%%%sat p%

If type=%

Display and operate Reference Manual

October 2019 00809-0100-3581

Figure 5-8: HART Chlorine, Dissolved Oxygen, and Ozone Menu Tree

36 Rosemount 5081

Page 37

7.00

CALIBRATE

PROGRAM DIAGNOSE

CALIbrAtE Std tEMP AdJ

CAL bF1

bF 1

bF1 4.01

CAL bF2

bF2

bF2 10.01

Std 7.00

SLOPE 59.01

tEMP 25.0

dIAGnOStiC tEMP dISPLAY

bUFFEr

ISOPOtnAL

LinE FrEq

PAMP=trAnS dEFAULt

rOFFSt 060

dIAG OFF

iMpiC ON

GFH 1500

GWH 1000

GWL 020

GFL 010

CAL 000

rEF LO

rFH 140

rWH 040

rWL 000

rFL 000

tAUTO On

tMAN 25.0

tYPE PH

tEMP C

OUtPUt Cur

COdE 000

bAUTO On

bUFFEr Std

StAbiLiSE

tIME 10

deLtA 00.02

tCOEF 00.00

ISO 07.00

Snr 07.00

LinE 60

FACtOrY

NO YES

InPut 58.9 SLOPE OFFSt GIMP 1000 rIMP 10 5081-P-Ht SoFt FAULtS

nonE

Sub-menu

PROMPT

Diag Message

HArd

Reference Manual Display and operate

00809-0100-3581 October 2019

Fieldbus pH Menu Tree

™

Figure 5-9: FOUNDATION

Reference Manual 37

Page 38

1400

CALIBRATE

PROGRAM DIAGNOSE

Std tEMP AdJ

Std 1000 tEMP 25.0

dIAGnOStiC dISPLAY

LinE FrEq

PAMP=trAnS dEFAULt

rOFFSt 060

dIAG OFF

iMpiC OFF

rEF LO

rFH 140

rWH 040

rWL 000

rFL 000

tYPE ORP

tEMP C

OUtPUt Cur

COdE 000

LinE 60

FACtOrY

YES

OFFSt 120 rIMP 10 5081-P-FF SoFt 00.02 FAULtS

nonE

Sub-menu

PROMPT

Diag Message

Hard 01

Display and operate Reference Manual

October 2019 00809-0100-3581

Figure 5-10: FOUNDATION Fieldbus ORP Menu Tree

38 Rosemount 5081

Page 39

5000 µS/cm

25.0 C

CAL key PROG key DIAG key HOLD key

Process Display

CALIBRATION

PROGRAM

DIAGNOSTICS

CALIbrAtE

SEnSOr 0

tEMP AdJ

Mtr CAL

CELL COnSt

tEMP SLOPE

tEMP

dISPLAY

SEtUP CuST

dEFAULT

AbS C

0 air

CELL COnSt

tSLOPE

CAL F

5081-C-FF

SoFt

HArd

Process display screen

Reference Manual Display and operate

00809-0100-3581 October 2019

Figure 5-11: FOUNDATION Fieldbus Contacting Conductivity Menu Tree

Reference Manual 39

Page 40

5000 µS/cm

25.0C 12.00mA

CAL key PROG key DIAG key HOLD key

Process Display

CALIBRATION

PROGRAM

DIAGNOSTICS

CALIbrAtE

SEnSOr 0

tEMP AdJ

CELL COnSt

tEMP SLOPE

tEMP

dISPLAY

SEtUP CuST

dEFAULT

AbS C

OFFSt

CELL COnSt

tSLOPE

CAL F

5081-T-FF

SoFt

HArd

FaULTs

Display and operate Reference Manual

October 2019 00809-0100-3581

Figure 5-12: FOUNDATION Fieldbus Toroidal Conductivity Menu Tree

40 Rosemount 5081

Page 41

MAIN DISPLAY

CALIBRATE PROGRAM DIAGNOSE

sensor 0 sensor Cal temp adj ph Cal

(free chlorine only)

air cal

In process

press 760 Grab spl

Cal 100

only)

(All)

Temp 025.0

auto Cal

Man Cal

std pH

pH slope

Cal bf1

bf1 4.01

Cal bf2

bf2 10.00

Cal bf1

bf1 7.00

Cal bf2

bf2 7.00

std 07.00 Slope 59.16

temp DEFAULT

Cal setup

Line freq

bar press

taUto On

tman 25.0

display

type --

Unit ppm

sensor stnd

Unit ppm

temp C

Output Cur

Code 000

if O

If Cl (free

and total)

If O

FACTORY NO

span Cal 0 Cal

stabilize

limit 00.05

time 10 SlOpe snGl Salnty 00.0

All

if chlorine if O

Line 60

PH ---

Pamp trans

Man 7.00

diaGnostiC

roffst 060

diaG OFF

lmptC On

GFI 1500

GFL 000

pH Cal

baUtO On

bUFFEr Std

StAbILISE

tIME 00

dELtA 0.02

Cl only

if On

if Off

Enter

Unit nnHG

pman 760

type 02

sensor Cur

0 Current

bar press

5081-a-Ht

faUlts

SUB MENU

PROMPT

delta 0.05

sensitivty

Reference Manual Display and operate

00809-0100-3581 October 2019

Figure 5-13: FOUNDATION Fieldbus Chorine, Dissolved Oxygen, and Ozone Menu Tree

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6 Programming basics

6.1 Programming

The following can be programmed in the Rosemount™ 5081:

• 4-20 mA outputs

• Current generated by the transmitter during hold

• Current generated by the transmitter when fault is detected

• Automatic temperature correction (enable or disable)

• Type of measurement

• Measurement range

• Factory default setting

6.2 Test 4-20 mA outputs and current generated during hold and faults

Procedure

1. Press PROG on the remote controller. The OUTPUT submenu appears.

2. Press ENTER. The screen displays the 4mA prompt.

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3. Use the arrow keys to change the setting. Press ENTER to save. The screen displays the 20mA prompt.

4. Use the arrow keys to change the setting. Press ENTER to save. The screen displays the HOLD prompt.

5. Use the arrow keys to change the setting to the output desired when the transmitter is in hold mode.

The range is 3.80 to 22.0 mA. If you select 00.00, the transmitter will hold the output value.

6. Press ENTER to save.

Note

The hold setting overrides the fault setting.

The screen displays the FAULT prompt.

7. Use the arrow keys to change the setting to the output desired when the transmitter is in fault mode.

The range is 3.80 to 22.0 mA. If you select 00.00, the transmitter will hold the output value.

8. Press ENTER to save. The screen displays the DPN prompt.

9. Use the arrow keys to change the setting. The range is 0 to 225.

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10. Press ENTER to save. The screen displays the TEST prompt.

11. Use the arrow keys to enter the desired test current. Press ENTER to start the test. Press EXIT to end the test.

12. Press RESET to return to the main display.

6.3 Correct temperature

Procedure

1. Press PROG. Press NEXT until the TEMP submenu appears on the display.

2. Press ENTER. The screen displays the T AUTO prompt.

3. Use the up or down arrow keys to enable (ON) or disable (OFF) the automatic temperature correction feature. Press ENTER to save. The screen displays the T MAN prompt.

4. Use the arrow keys to change to the desired temperature. To enter negative numbers, press the left or the right arrow key until no digit is

flashing. then press the up or down arrow keys to display the negative sign. The range is 23 to 266 ° F (-5.0 to 130 °C).

5. Press ENTER to save. Press RESET to return to the main display.

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Note

If you disabled T AUTO in Step 3, then the transmitter will use the temperature entered in this step in all subsequent measurements, no matter the actual process temperature.

6.4 Set up a custom curve (conductivity measurements only)

Use custom curves to correlate conductivity to concentration of the measured liquid. The Rosemount 5081 has programmable custom curves that can create a curve (second order) from three to five user supplied points. If it only uses two points, then then the transmitter creates a linear curve (straight lin). In order for the curve to be accurate, take the data points from the liquid having the same reference temperature.

To obtain best results, select data points that are representative of the typical operating range and have at least 5% difference in conductivity values. Observe the graph of conductivity vs. concentration for the particular liquid to ensure that unsuitable points are avoided. Unsuitable points include conductivity values with two concentrations associated with them. In addition to unsuitable points, record any critical points - points that best describe the curve. Following these general guidelines will provide optimal results.

Enter the first point (COND 1) at the normal operating condition. Then enter other points above and below COND 1. Nonlinear conductivity curves require additional data points to characterize these regions. Do not use the same data point more than once and only use actual data (do not interpolate data points).

Note

The default values for the custom curve are three data points, reference temperature of 77 °F (25 °C), and a linear temperature slope of two percent/°C. This combination will yield the best results in most applications. If the normal temperature is over 104 °F (40 °C) or under 50 °F (10 °C), change the reference temperature to the normal process temperature. If known, use the temperature slope at the reference temperature.

Procedure

1. From the main menu, select PROG and then press NEXT four times.

SETUP CUST appears.

2. Press ENTER.

T REF appears.

3. If needed, change the reference temperature from the factory default 77 °F (25 °C) to a different reference temperature for the process. Press ENTER.

UNIT appears.

4. Press the up or down arrow to select the desired measurement units: µS (microsiemens), mS (millisiemens), none (no units displayed), % (percent), or ppm (parts per million); then press ENTER.

NUM PTS appears.

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5. Press up or down arrows to select the desired number of data points for a custom conductivity curve. Select 2 to generate a linear relationship for conductivity and

concentration at the given temperature.

a) Enter the concentration for point 1 (displayed as µS 1). Press ENTER.

b) Enter the known conductivity for point 1 in µS/cm. Press ENTER.

c) Complete this process for additional known data points. Press ENTER.

CALC CUST appears briefly.

d) Press ENTER.

PROCESSING appears briefly; then APPLY CUST appears.

e) Press ENTER to register the custom curve into memory and return to the

SETUP CUST screen.

The custom curve will now be used to display and output all conductivity measurement when the operator selects CUST as the measurement type in the Display menu.

6.5 Restore to factory default settings

The operator can erase user-defined configurations to return the transmitter to the factory default settings.

Procedure

1. Press PROG on the remote controller.

2. Press NEXT until DEFAULT appears in the display. Press ENTER.

3. Use the up and down arrows to toggle between NO and YES. Press ENTER to return to the factory default settings.

6.6 Set access (security) code

6.6.1 Security overview

The access (security) code prevents program and calibration settings from accidental changes. Emerson ships the transmitter with the access (security) code disabled.

6.6.2

Enter the access (security) code

Procedure

1. If calibration and program settings are protected with a security code, press PROG or CAL on the infrared remote controller. The ID screen appears.

2. Use the editing keys to enter the code. Press ENTER. If the code is correct, the first sub-menu appears. If the security code is incorrect, the process display reappears.

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6.6.3 Retrieve a lost security code

Procedure

1. If the you forget the security code, enter 555 at the ID prompt and press ENTER. The transmitter displays the present code.

2. Press EXIT to return to the process display.

3. Press PROG or CAL. The ID screen appears.

4. Use the editing keys to enter the security code. Then press ENTER. The first sub-menu under the selected menu appears.

6.7 Activate or deactivate HOLD

Activating HOLD keeps the transmitter output at the last value or sends the output to a previously determined value. This is particularly useful when doing calibrations. During calibrations, the sensor may be exposed to solutions that have concentrations outside the normal range of the process. HOLD prevents false alarms and undesired operation as a result of that reading. You can deactivate HOLD when the sensor is reinstalled in the process stream and the readings have relatively stabilized.

Procedure

1. Press HOLD on the remote controller. The HOLD prompt appears in the display.

2. Press 3 (up) or 5 (down) to toggle HOLD between ON and OFF.

3. Press ENTER to save.

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7 Measurements

7.1 Calibrating pH sensors

7.1.1 Calibration overview

The Calibration menu allows you to calibrate the pH and temperature response of the sensor. To calibrate, use either the manual or the auto-calibration option. In both cases, the transmitter does a two-point calibration for pH and one-point standardization against a reference thermometer for temperature. In auto-calibration, the transmitter automatically stores the temperature-corrected calibration data. In manual calibration, you have to enter buffer values. The values are only registered when the readings are stable (automatically determined by the transmitter). All calibration procedures are guided by prompts on the display.

7.1.2

7.1.3

Calibration standards (buffer solutions)

• Calibrations are critical to make accurate pH measurements.

• Emerson recommends that the value of one of the pH buffer solutions is lower than the

pH of the process stream and the value of the other pH buffer solution is higher than the pH of the process stream.

• For best results, make sure that the temperature of the solution is the same

temperature as that of the sensor. Allow the entire measurement cell, sensor, and solution to reach relatively constant temperature.

• Using buffers at high temperatures can cause evaporation, which will change the

concentration of the buffer. The change in concentration causes a change in the pH, thus resulting in an inaccurate calibration.

• Buffers have limited shelf lives. Do not use a buffer if the expiration date has passed.

Store buffers at controlled room temperatures.

• Do not reuse buffer solutions. Protect buffers from excessive exposure to air. Exposure

to air can cause changes in the pH of the buffer solution.

• Always rinse the sensor with DI water and remove excess water by dabbing with a clean

tissue before placing it in a buffer. Only dab the sensor and do not wipe it. Wiping the sensor builds static charge which alters the reading.

Auto-calibrate

Prerequisites

Ensure that auto-calibration is turned ON and the appropriate buffers are used.

Procedure

1. Press CAL on the IRC to enter the CALIBRATE menu.

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The CALIBRATE sub-menu appears.

2. At the CALIBRATE sub-menu, press ENTER. The CAL bF1 prompt appears.

3. Rinse the sensor and place it in the first buffer. Be sure the glass bulb and the temperature element are completely submerged. Keep the sensor at least 3 in. below the liquid level. Do not rest the sensor on the glass bulb. Dislodge any trapped bubbles by swirling the sensor body.

4. Press ENTER.

BF1 flashes until the measured pH meets the programmed stability limits. If the pH

reading is not relatively stable after 20 minutes, the transmitter automatically leaves the CALIBRATE menu and returns to the main display. If this occurs, consult

Diagnostics and troubleshooting for assistance. Once the reading is stable, the

display moves forward by showing a flashing number with the nominal pH.

5. Change the value by using the up and down arrows until the correct pH of the buffer solution appears. Press ENTER to save the first calibration point.

CAL BF2 appears.

6. Remove the sensor from the first buffer.

7. Rinse the sensor and place it in the second buffer solution. Again, make sure the bulb is completely submerged and the bubbles are dislodged by swirling the sensor body.

8. Press ENTER.

BF2 flashes until the reading is stable.

9. Repeat steps Step 4 and Step 5. The calibration is now complete, but the transmitter remains in the CALIBRATE submenu for two minutes after you press ENTER.

10. Remove the sensor from the buffer and reinstall it into the process stream. If the HOLD feature was used, be sure to turn off HOLD.

The sensor will not calibrate if the electrode slope (calculated by the transmitter during calibration) is unacceptable. The transmitter displays a SLOPE ERR HI or

SLOPE ERR LO error message. Refer to Diagnostics and troubleshooting for

assistance.

Note

To display the electrode slope, press CAL on the IRC. The CALIBRATE sub-menu appears. Press NEXT. The STD sub-menu appears. Press ENTER. The STD prompt appears. Press ENTER again, and the slope appears on the display. For a good sensor, the slope is generally 50 to 60 mV.

7.1.4

50 Rosemount 5081

Calibrate manually

Prerequisites

Ensure that auto-calibration is OFF and the appropriate buffers are used.

Procedure

1. Press CAL on the IRC to enter the CALIBRATE menu.

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The CALIBRATE sub-menu appears.

2. At the CALIBRATE sub-menu, press ENTER. The CAL BF1 prompt appears.

3. Rinse the sensor with DI water and place it in the first buffer along with a calibrated thermometer. Submerge the sensor tip at least 3 in. (76 mm) below the liquid level. Do not rest the sensor on the glass bulb. Dislodge any trapped bubbles by swirling the sensor body.

4. Once the pH reading and temperature are relatively stable, press ENTER. Use the editing keys to change the flashing display to the appropriate pH of the buffer solution. Press ENTER to save the value as buffer BF1. The transmitter expects a reading to be entered within 20 minutes after the CAL

BF1 prompt. If you do not press ENTER, the transmitter exits the CALIBRATE menu

and returns to the process mode.

5. At the CALBF2 prompt, remove the sensor from the first buffer. Repeat steps Step 3 and Step 4.

The calibration is now complete, but the transmitter remains in the CALIBRATE submenu for two minutes after you press ENTER.

6. Remove the sensor from the buffer and reinstall it into the process stream. If the HOLD feature was turned on, be sure to turn off HOLD.

The sensor will not calibrate if the electrode slope (calculated by the transmitter during calibration) is unacceptable. The transmitter displays a SLOPE ERR HI or SLOPE ERR LO error message. Refer to Diagnostics and troubleshooting for assistance.

7.1.5

Note

Standardize for pH

Use standardization to match the transmitter values with those of another transmitter. The transmitter converts the difference between the two pH values into an equivalent voltage, called the reference offset.

Note

If a sensor that has been calibrated with buffers is standardized, then placing it back in the buffer will show a different measured pH than that of the buffer due to the standardization offset.

Procedure

1. Press CAL on the IRC to enter the CALIBRATE menu. The CALIBRATE submenu appears.

2. At the CALIBRATE submenu, press NEXT. The STD submenu appears.

3. Press ENTER to enter the STD prompt.

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The process pH and temperature should be relatively stable.

4. Take a grab sample from the process stream as close to the pH sensor as possible. This transmitter reading is called the pH_trans.

5. Measure the pH of the sample (pH_std) using the second pH meter.

6. Note the current process reading (pH_curr). Calculate the corrected reading from the equation: ph_corr = ph_curr + (pH_std - pH_trans)

• pH_corr = corrected pH value

• pH_curr = current pH value

• pH_std = standard instrument's pH value

• pH_trans = measured sample's pH value

7. Use the editing keys to enter the pH_corr value calculated using the equation above. Press ENTER to save the value. If the corrected value is acceptable, then the display shows the slope (current electrode slope).

8. If the slope is acceptable, press EXIT. If the slope is unacceptable, use the editing keys to change it. Then press ENTER.

9. To leave the CALIBRATE menu, press EXIT.

7.2 Calibrating oxidation reduction potential (ORP) sensors

7.2.1 Oxidation reduction potential (ORP) overview

ORP is a function of temperature. The accuracy of a sensor/transmitter loop is about ±1 °C. A new sensor does not need to be calibrated often. Only calibrate the loop when:

1. ±1 °C is not acceptable.

2. You suspect an error in temperature measurement

7.2.2

Calibrate temperature with an oxidation reduction potential (ORP) sensor

Procedure

1. Place the ORP sensor and a reference thermometer in an insulated container of water at ambient temperature. Keep the sensor submerged at least 3 in. (76 mm) below the water level. Stir continuously and wait at least 20 minutes for the water, sensor, and thermometer to reach a constant temperature.

2. Press CAL on the IRC to enter the CALIBRATE menu. The STD submenu appears.

3. At the STD submenu, press NEXT. The TEMP ADJ submenu appears.

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4. Press ENTER to display the temperature editing prompt.

5. Compare the temperature displayed by the transmitter with the temperature measured by the reference thermometer. If there is a discrepancy between the two values, use the editing keys to change the measured value to that of the thermometer.

Note

The reading cannot be changed more than 15 °C.

6. Press ENTER. The transmitter saves the value, and the display returns to the TEMP ADJ submenu.

7. Press EXIT to leave the CALIBRATE menu.

8. Check for linearity by measuring the temperature of water: -10 to -15 °C and +10 to +15 °C than the water used for calibration.

7.2.3

7.2.4

Standardize with an oxidation reduction potential (ORP) sensor

ASTM d 1498-93 gives procedures for making iron (ii) - iron (iii) and quinhydrone ORP standards. Emerson recommends the iron (ii) - iron (iii) standard. It is fairly easy to make and has a shelf life of approximately one year; in contrast, quinhydrone standards contain toxic quinhydrone and have only an eight hour shelf life. Iron (ii) - iron (iii) standard is available from Rosemount™ as PN R508-16OZ. The ORP of the standard solution measured against a silver-silver chloride reference electrode is 476 ± 20 mV at 77 °F (25 °C).

Procedure

1. Press CAL on the IRC to enter the CALIBRATE menu. The STD submenu appears.

2. Rinse the sensor with DI water and place it in the ORP standard with a reference thermometer. Ensure that the ORP sensor is submerged at least 3 in. (76 mm) below the water level.

3. Once the temperature and ORP readings are stable, press ENTER.

4. Use the editing keys to change the flashing display to the desired ORP reading. Press ENTER to save.

5. Press EXIT to return to the main display.

Match transmitter to oxidation reduction potential (ORP) sensor's temperature element

Procedure

1. Press PROG on the IRC.

2. Press NEXT until the TEMP submenu appears in the display. Press ENTER.

3. Press EXIT to return to the main display.

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7.3 Calibrating contacting and toroidal conductivity sensors

7.3.1 Overview of calibrating contacting conductivity sensors

Contacting conductivity sensors do not require frequent calibrations. The sensors are ready to be installed right out of the box.

7.3.2 Calibrate contacting conductivity sensors

Procedure

1. Pres CAL on the IRC. Press ENTER. The CALIBRATE submenu appears.

2. Place the sensor in a standard solution of known conductivity and allow the measurement reading to become relatively stable.

3. Press ENTER to access the CAL segment with the flashing prompt.

4. Use the IRC editing keys to enter the conductivity value of the standard solution. Press ENTER.

5. Press EXIT to return to the main display.

7.3.3

7.3.4

Zero the sensor

Procedure

1. Press CAL and then NEXT to enter the SENSOR 0 menu.

2. Press ENTER to access the SENSOR 0 submenu.

3. Hold the sensor in the air and press ENTER again to zero the sensor.

4. Press EXIT to return to the SENSOR 0 submenu.

Adjust temperature

Procedure

1. Press CAL and then NEXT until you see TEMP.

2. Press ENTER. The TEMP submenu appears.

3. Place the sensor in any solution of known temperature. Allow the temperature of the sensor to become relatively stable.

4. Use the editing keys of the IRC to change the values as needed.

5. Press ENTER to standardize the temperature reading and return to the TEMP ADJ screen.

6. Press EXIT to return to the main display.

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7.3.5 Calibrate in-process

Procedure

1. Press CAL and then NEXT three times to access MTR CAL.

2. Use the IRC to go through the on-screen prompts.

3. Press EXIT to return to the main display.

7.3.6 Calibrate temperature slope

Procedure

1. From the CAL menu, press NEXT until TEMP SLOPE displays.

2. Use the IRC arrow keys to enter the slope. Press ENTER to register the slope in the memory of the transmitter. Press EXIT to return to the main screen.

3. If you don't know the temperature slope of the process, then refer to the below guide:

7.3.7

• Acids: 1.0 percent to 1.6 percent per °C

• Bases: 1.8 percent to 2.2 percent per °C

• Salts: 2.2 percent to 3.0 percent per °C

• Water: 2.0 percent per °C

4. Press ENTER to proceed to the T SLOPE submenu with the flashing prompt. Use the IRC keys to generate the desired slope value. Press ENTER.

5. Press EXIT to return to the main screen.

Calibrate output

Procedure

1. Wire an accurate milliammeter as shown in Figure 7-1.

Figure 7-1: Milliammeter Wiring

2. Press CAL on the IRC.

3. Press NEXT until the OUTPUT CAL submenu appears. Press ENTER.

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4. Use the arrow keys to change the display to match the reading from the milliammeter. Press ENTER.

5. Press RESET to return to the main display.

7.4 Calibrating dissolved oxygen, ozone, free chlorine, total chlorine, and ozone sensors

7.4.1 Calibrating amperometric sensors

You can calibrate amperometric sensors in multiple ways: zeroing, air calibrations, dual slope calibrations, and in process calibrations.

7.4.2

Zero the sensor

Procedure

1. Place the sensor in a solution of 5% sodium sulfite (Na2SO3) in water. Ensure that air bubbles are not trapped against the membrane.

2. Go to the main display; press DIAG and then NEXT. The SENSOR CUR prompt appears.

3. Press ENTER to view the sensor current. Make sure the sensor reaches its zero current.

This may require several hours. Do not start the zero routine until the sensor has been in zero solution for at least two hours.

4. Press CAL on the IRC. The SENSOR 0 prompt appears.

5. Press ENTER. The screen shows the appropriate value correlating to the zero value. The screen shows 0.02. The reading must be below 0.02 ppm for the zero calibration to be accepted.

6. To change the zero limit, use the editing keys and then press ENTER. The TIME DELAY message appears and remains until the zero current is below the concentration limit. If the current is already below the limit, TIME DELAY will not appear.

7. To bypass the time delay, press ENTER. When the procedure is complete, 0 DONE appears.

8. Press EXIT.

9. Press RESET to return to the main display.

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7.4.3 Calibrate in air (dissolved oxygen)

Procedure

1. Remove the sensor from the process liquid. Use a soft tissue and a wash bottle to clean the membrane. Dry it by blotting.

The membrane must be completely dry during air calibration.

2. Pour some water into a beaker and suspend the sensor with the membrane approximately ½ in. (approximately 1 cm) above the water surface.

Keep the sensor out of direct sunlight.

3. Monitor the dissolved oxygen and temperature reading. Once the readings are relatively stable, begin the calibration.

It may take 10 - 15 minutes for the sensor reading in the air to stabilize.

4. Press CAL on the IRC.

5. Press NEXT. The SENSOR CAL submenu appears.

6. Press ENTER. The AIR CAL prompt appears.

7. Press ENTER.

8. Select the units. Then press NEXT.

9. Use the arrow keys to enter the barometric pressure. Press ENTER when done. The TIME DELAY message appears and remains until the sensor reading is relatively stable.

10. To bypass the time delay, press ENTER.

CAL DONE appears when the calibration is complete.

11. Press EXIT.

12. To return to the main display, press RESET.

7.4.4

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Calibrate in process (dissolved oxygen)

You can calibrate the sensor against a standard instrument.

Procedure

1. Press CAL on the IRC.

2. Press NEXT. The SENSOR CAL submenu appears.

3. Press ENTER.

4. Press NEXT. The AIR CAL prompt appears.

5. Press NEXT. The INPROCESS prompt appears.

6. Press ENTER.

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The TIME DELAY message appears and will remain until the sensor is relatively stable. To bypass the time delay, press ENTER. The GRAP SPL message appears.

7. Press ENTER.

8. Use the arrow keys to change the flashing display to the value indicated by the standards instrument. Press ENTER.

9. Press RESET to return to the main display.

7.4.5 Calibrate full scale (free chlorine, total chlorine, ozone)

Procedure

1. Place the sensor in the process liquid. Ensure that the pH sensor is calibrated or the pH value is entered in case of manual pH correction, if applicable.

2. Adjust the chlorine concentration until it is near the upper end of the control range. Wait until the reading is relatively stable before starting the calibration.

3. Press CAL on the IRC.

4. Press NEXT. The SENSOR CAL submenu appears.

5. Press ENTER. The TIME DELAY message appears and will remain until the sensor reading is relatively stable. To bypass the time delay, press ENTER. The GRAB SPL prompt appears.

6. Take a sample of the process liquid and determine the concentration of chlorine in the sample. Press ENTER.

7. Press RESET to return to the main display.

7.4.6

58 Rosemount 5081

Calibrate dual slope (free chlorine, total chlorine)

Procedure

1. Zero the sensor.

2. Place the sensor in the process liquid. Ensure that the pH sensor is calibrated or the pH valve is entered in case of manual pH correction, if applicable.

3. Press CAL on the IRC. Press NEXT. The SENSOR CAL prompt appears.

4. Press ENTER. The CAL PT1 prompt appears.

5. Adjust the chlorine concentration until it is near the upper end of the linear range of the sensor. Press NEXT. The TIME DELAY message appears and will remain until the sensor reading is

relatively stable. To bypass the time delay, press ENTER. The GRAB SPL prompt appears.

6. Take a sample of the process liquid and determine the concentration of chlorine in the sample.

7. Press ENTER.

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The PT1 prompt appears.

8. Use the arrow keys to change the flashing display to the concentration of chlorine determined in the grab sample. Press ENTER to save. The CAL PT2 prompt appears.

9. Adjust the concentration of chlorine until it is near the top end of the range. Press ENTER. The TIME DELAY message appears and will remain until the sensor reading is

relatively stable. To bypass the time delay, press ENTER. The GRAB SPL prompt appears.

10. Take the sample of the process liquid and determine the concentration of chlorine in the sample.

11. Press ENTER. The PT2 prompt appears.

12. Use the arrow keys to change the flashing display to the concentration of chlorine determined in the grab sample. Press ENTER to save.

13. Press RESET to return to the main display.

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8 Diagnostics and troubleshooting

8.1 Warning and fault messages

The Rosemount™ 5081 transmitter continuously monitors the measurement loop (sensor and transmitter) for conditions that cause inaccurate measurements. When a problem occurs, the transmitter displays either a warning or fault message. A warning alerts you that a potentially system disabling condition exists. If you don't fix the problem, there is a high probability that the measurement will be incorrect. A fault alerts you that a system disabling condition exists. If a fault message is showing, regard all measurements as incorrect.

When a warning condition exists:

1. The main display remains stable; it does not flash.

2. A warning message appears alternately with the temperature display. See Figure

8-1. See Troubleshooting when a diagnostic message is showing for an explanation

of the different warnings and suggested ways of correcting the problem.

Figure 8-1: Warning Annunciation

When a Fault exists:

1. The main display flashes.

2. The words FAULT and HOLD appear in the main display.

3. A fault message appears alternately with the temperature/output display. See

Figure 8-2. See Troubleshooting when a diagnostic message is showing for an

explanation of the different fault messages and suggested ways of correcting the problem.

4. The output current will remain at the present value or go to the programmed fault value.

5. If the transmitter is in Hold when the fault occurs, the output remains at the programmed hold value. To alert you that a fault exists, the word FAULT appears in

the main display, and the display flashes. A fault or diagnostic message also appears.

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6. If the transmitter is simulating an output current when the fault occurs, the transmitter continues to generate the simulated current. To alert you that a fault exists, the word FAULT appears in the display, and the display flashes.

Figure 8-2: Fault Annunciation

When a a fault occurs, the display appears as pictured above. To further alert you that measurements are in error, the display flashes. Diagnostic messages appear in the temperature/output area on the screen.

8.2 pH/ORP diagnostics and troubleshooting

8.2.1 Calibration errors

If an error occurs during calibration, an error message appears in the main display and the transmitter does not update the calibration. The calibration errors are Std Err, SLOPE

Err LO, and SLOPE Err HI. See Troubleshooting when a diagnostic message is showing

for an explanation of the error messages and suggested ways of correcting the problem.

8.2.2

8.2.3

General troubleshooting

Procedure

1. Look for a diagnostic message on the display to help identify the problem. Refer to Troubleshooting when a diagnostic message is showing for an explanation

of the message and a list of the possible problems that triggered it.

2. Refer to Troubleshooting when no diagnostic message is showing for common measurement problems and the recommended actions to resolve them.

3. Follow the step-by-step troubleshooting approach, offered in Displaying diagnostic

variables, to diagnose and correct less common or more complex problems.

Troubleshooting when a diagnostic message is showing

The Rosemount 5081-P pH/ORP transmitter continuously monitors the measurement loop (sensor and transmitter) for problems. If a problem is detected, the transmitter

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displays a fault or error message. The message appears in the temperature/output area of the main display. The table lists each diagnostic message and the section to consult for help.

Message Section

GLASSFAIL GLASSFAIL

GLASSWArn GLASSWArn

rEF FAIL rEF FAIL

rEF WArn rEF WARn

CALIbrAtE CALIbrAtE

tEMP HI tEMP HI and tEMP LO

tEMP LO tEMP HI and tEMP LO

LInE FAIL LinE FAIL

InPUt WArn InPUt WArn

SLOPE Err LO SLOPE Err LO

SLOPE Err HI SLOPE Err HI

Std Err Std Err

rOM FAIL rOM FAIL or CPU FAIL

CPU FAIL rOM FAIL or CPU FAIL

AdC WArn AdC WArn or CyCLE PWr

CyCLE PWr AdC WArn or CyCLE PWr

WrItE Err WritE Err

FACt FAIL FACt FAIL

GLASSFAIL

GLASSFAIL is an electrode fault message. It means the glass impedance is outside the

programmed Glass Fault High (GFH) or Glass Fault Low (GFL) limit. Glass Fault High suggests the electrode is aging or the electrode is not immersed in the process liquid. Glass Fault Low implies that the pH sensitive glass is cracked. GLASSFAIL also appears if

inappropriate limits have been entered into the transmitter.

If the measurement system was previously commissioned and operating correctly,

GLASSFAIL likely means a real problem exists. However, if the system is being started up

or if the advanced diagnostic feature is being used for the first time, GLASSFAIL could be caused by a miswired sensor or by programmed limits that are not correct for the sensor.

Note

GLASSFAIL is a sensor diagnostic message. Sensor diagnostic messages are optional.

They can be turned off.

Recommended actions

1. Be sure the sensor is completely immersed in the process liquid.

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If the diagnostic message disappears, the sensor is in good condition.

If the diagnostic message remains, go to Step 2.

2. Measure the glass impedance. See Testing the transmitter by simulating the pH for the procedure. Note the reading.

If the glass impedance is low (< 40 megohms)...

a. Check preamp location in program menus (PAMP = _____).

• If the location is incorrect, go to 2.b.

• If after selecting the correct location of Preamp in the Program menu, the

glass impedance is still low, go to Step b.

b. Calibrate the sensor.

• If the sensor calibrates properly...

1. The sensor is in good condition, but the Glass Fail Low (GFL) limit is set too high.

2. Lower the GFL limit to about 10 megohms below the glass impedance value (GIMP).

3. If the Glass Warning Low (GWL) message was also flashing, lower the limit from its former value by the same amount the GFL was lowered from its former value.

• If the sensor cannot be calibrated, the pH glass membrane is likely

cracked and the sensor must be replaced. The crack in the glass may not be visible or may be difficult to see.

If the glass impedance is high (> 800 megohms)...

a. Check that the sensor is correctly wired to the transmitter. Pay particular

attention to the following:

1. For Rosemount PLUS (+) and TUpH sensors with integral preamplifiers,

the blue solution ground wire must be attached to TB-8 (SOL GND), and the gray reference in wire must be attached to TB-7 (REF IN).

Note

TB-8 means terminal 8 on the terminal board.

2. If the sensor was wired with the blue solution ground wire unattached

and a jumper between the terminals TB-8 and TB-7, remove the jumper and reattach the blue solution ground wire to TB-8. Keep the gray reference in wire attached to TB-7.

3. For Rosemount PLUS (+) and TUpH sensors that do not have an

integral preamplifier, attach the blue solution ground wire to TB-8 or, better, leave the blue wire unattached and jumper TB-7 to TB-8.

4. If the sensor does not have a blue solution ground wire, jumper

terminals TB-7 and TB-8.

• If the wiring was correct and the glass impedance is still too high,

go on to 2.b.

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• If correcting wiring errors causes the diagnostic message to

disappear, the sensor is in good condition.

• If after correcting wiring errors, the glass impedance is still high, go

on to Step b.

b. Inspect and clean the sensor. After cleaning the sensor, calibrate it. Be sure to

note the sensor slope.

• If cleaning the sensor lowers the impedance below 800 megohms:

1. The sensor is in good condition.

2. Return the calibrated sensor to service.

• If cleaning does not lower the glass impedance and the sensor can be

calibrated:

1. The sensor is probably in good condition; however, it may be nearing the end of its life. The electrode slope is a good indicator of remaining life.

Slope Condition of sensor

54-60 mV/unit pH Sensor is in good condition.

48-50 mV/unit pH Sensor is nearing the end of its life. Once the

slope drops below 48 mV/unit pH, the sensor can no longer be calibrated.

2. The Glass Fail High (GFH) limit is probably set too low for the sensor. Set the GFH limit to about 150 megohms greater than the measured glass impedance.

3. If the GLASSWArn message was also flashing, raise the GWH limit from its former value by the same amount the GFH was raised from

its former value.

• If cleaning does not lower the glass impedance and the sensor cannot be

calibrated, the sensor has failed and should be replaced.

GLASSWArn

GLASSWArn is an electrode fault message. It means the glass impedance is outside the

programmed Gas Warning High (GWH) or Glass Warning Low (GWL) limit. Ideally, when the measurement system exceeds the glass warning limits, you will have adequate time to diagnose and correct problems before a failure occurs. High impedance implies the electrode is aging or the sensor is not completely submerged in the process liquid. Low impedance suggests the pH sensitive glass is cracked. The message also appears if inappropriate limits have been entered into the transmitter.

If the measurement system was previously commissioned and operating correctly,

GLASSWArn likely means a real problem exists. However, if the system is being started up

or if the advanced diagnostic feature is being used for the first time, GLASSWArn could be caused by a miswired sensor or by programmed limits that are not correct for the sensor.

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Note

GLASSWArn is a sensor diagnostic message. All sensor diagnostic messages are optional.

They can be turned off.

Troubleshooting GLASSWArn problems is exactly the same procedure as troubleshooting

GLASSFAIL problems. Refer to GLASSFAIL.

rEF FAIL

rEF FAIL is an electrode fault message. rEF FAIL means that the reference impedance

exceeds the programmed reference high fault (RFH) limit. A plugged or dry reference junction is the usual cause of a high reference impedance. High reference impedance also occurs if the sensor is not submerged in the process liquid or if inappropriate limits have been entered into the transmitter.

If the operator previously commissioned the measurement system and it was operating correctly, rEF FAIL likely means a real problem exists. However, if the operator is just

starting up the system or using the advanced diagnostic feature for the first time, rEF

FAIL could be caused by a miswired sensor or by programmed limits that are not correct

for the sensor.

Note

rEF FAIL is a sensor diagnostic message. All sensor diagnostic messages are optional.

They can be turned off.

Recommended actions

1. Be sure the sensor is completely immersed in the process liquid.

• If the diagnostic message disappears, the sensor is in good condition.

• If the diagnostic message remains, go to Step 2.

2. Check that the sensor is properly wired to the transmitter. Be sure the reference in wire is attached to TB-7 and the solution ground wire is attached to TB-8.

Note

TB-8 means terminal 8 on the terminal board.

• If correcting wiring problems makes the diagnostic message disappear, the

sensor is in good condition.

• If the wiring is correct and the message still remains, go to Step 3.

3. Measure and make a note of the reference impedance (rIMP). See Testing the

transmitter by simulating the pH.

• If the reference impedance is low (< 70 kilohms)...

a. The reference electrode is in good condition. pH sensors manufactured

by Rosemount use low impedance silver/silver chloride reference electrodes.

b. The reference failure high (RFH) limit is probably set too low. Change the

limit to a value about 50 kilohms greater than the measured reference impedance. If rEF WARN was also displayed, change the reference

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warning high (RWH) limit to about 25 kilohms above the measured reference impedance.

• If the reference impedance is high (> 70 kilohms)...

a. The sensor may be dirty, in which case cleaning it will lower the

impedance. If the sensor is rebuildable, the reference electrolyte may be depleted. Finally, the sensor may be in good condition. The warning and failure limits are simply set too high.

b. Inspect and clean the sensor. If the sensor is rebuildable, replace the

reference junction and replenish the electrolyte solution. Refer to the sensor reference manual for details. Check the reference impedance again.

— If cleaning the sensor reduces the impedance...

1. The sensor is in good condition. Calibrate the sensor and return it to the process.

2. Change the reference failure high (RFH) limit to a value about 50 kilohms greater than the measured reference impedance. If

rEF WARN was also displayed, change the reference warning

high (RWH) limit to about 25 kilohms above the measured reference impedance.

— If cleaning does not reduce the impedance and the sensor is not

rebuildable...

1. Try the reference junction rejuvenation procedure. The rejuvenation procedure may not work. At best, it will get a little more life out of a sensor with a plugged reference.

2. Whether or not the rejuvenation procedure worked, go to 3.c.

c. Recalibrate the sensor using the autocalibration procedure.

— If the sensor can be calibrated:

1. The sensor is in good condition. Return it to the process.

2. Change the reference failure high (RFH) limit to a value about 50 kilohms greater than the measured reference impedance. If

rEF WARN was also displayed, change the reference warning

high (RWH) limit to about 25 kilohms greater than the measured reference impedance.

— If the sensor cannot be calibrated, the sensor has failed and must be

replaced.

rEF WARn

rEF WArn is an electrode fault message. It means the reference electrode impedance

exceeds the programmed reference warning high (RWH) limit. Ideally, when the measurement system exceeds the warning limits, you will have adequate time to diagnose and correct problems before a failure occurs. A high reference impedance implies that the liquid junction is plugged or the reference electrolyte is depleted. The message also appears if an inappropriate limit has been entered into the transmitter.

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If the measurement system was previously commissioned and operating correctly, rEF

WArn likely means a real problem exists. However, if the system is being started up or if the

advanced diagnostic feature is being used for the first time, rEF WArn could be caused by a miswired sensor or by programmed limits that are not correct for the sensor.

Note

rEF WArn is a sensor diagnostic message. Sensor diagnostic messages are optional. They

can be turned off.

Troubleshooting rEF WArn problems is exactly the same as troubleshooting rEF FAIL problems. Refer to rEF FAIL.

CALIbrAtE

CALIbrAte is a diagnostic intended for future use. If the CALIbrAte message is showing,

disable CALIbrAte.

tEMP HI and tEMP LO

tEMP HI and tEMP LO mean the transmitter has detected a problem with the

temperature measuring circuit. The problem may lie in the sensor, the cable, or the transmitter. The determination of temperature is an integral part of the pH measurement. Therefore, failure of the temperature measuring circuit is a system disabling condition. However, in an emergency, automatic temperature compensation can be disabled and the transmitter placed in manual temperature compensation. For manual temperature compensation, choose a temperature equal to the average temperature of the process. The resulting pH reading will be in error. The more variable the temperature and the further the pH from 7, the greater the error.

Recommended actions

1. Check wiring, jumper settings, and software settings.

a. Check the wiring between the sensor and the transmitter. Pay particular

attention to TB=3 (RTD RTN), TB-4 (RTD SN), and TB-5 (RTD RTN ).

Note

TB-3 means terminal 3 on the terminal board.

b. Be sure the software settings match the type of resistance temperature

device (RTD) in the sensor.

• If the diagnostic message disappears, the sensor is in good condition.

• If the message persists, go to Step 2.

2. Check the sensor. Disconnect the RTD leads and measure the resistances shown in

Figure 8-3.

The measured resistance should agree with the value in Table 8-1 to within about one percent. If the measured resistance is appreciably different (between one and five percent) from the value shown, the operator can calibrate out the discrepancy.

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Figure 8-3: Three-Wire RTD

A. Compare resistance between these wires to the values in Table 8-1. B. Resistance between these wires should be less than 2 ohms.

Consult Table 8-1 for resistance-temperature data. Lead resistance is about 0.05 ohm/ft at 77 °F (25 °C). Therefore, 15 feet of cable increases the resistance by about

1.5 ohm. The resistance between the RTD return and RTD sense leads should be less than 2 ohms.

Table 8-1: RTD Resistance Values

Temperature Pt-100 resistance Pt-1000 resistance

0 °C (32 °F) 100.0 ohms 1000 ohms

10 °C (50 °F) 103.9 ohms 1039 ohms

20 °C (68 °F) 107.8 ohms 1078 ohms

25 °C (77 °F) 109.6 ohms 1096 ohms

30 °C (86 °F) 111.7 ohms 1117 ohms

40 °C (104 °F) 115.5 ohms 1155 ohms

50 °C (122 °F) 119.4 ohms 1194 ohms

60 °C (140 °F) 123.2 ohms 1232 ohms

70 °C (158 °F) 127.1 ohms 1271 ohms

80 °C (176 °F) 130.9 ohms 1309 ohms

90 °C (194 °F) 134.7 ohms 1347 ohms

100 °C (212 °F) 138.5 ohms 1385 ohms

• If a connections is open or shorted and it should not be, the sensor has failed.

Replace the sensor.

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• If the measured resistances are acceptable, go to Step 3.

3. Check the transmitter. Disconnect the RTD sensor leads and wire the circuit shown in Figure 8-4. Set the resistance to the value for 25 °C (77 °F) shown in Table 8-1. The measured temperature should equal 25 °C (77 °F) within ±1 °C.

Figure 8-4: Temperature Simulation into the Rosemount 5081 pH/ORP Transmitter

A. Terminal board B. RTD return C. RTD sense

D. RTD in

E. Jumper F. Standard resistor(s) to stimulate RTD

• If the measured temperature is correct, the transmitter is working properly.

• If the measured temperature is incorrect, calibrate the transmitter against the

standard resistance equivalent to 77 °F (25 °C). Change the resistance and verify that the temperature reading changes to the correct value.

— If the transmitter works properly after temperature calibration, the original

calibration was in error. Re-attach the RTD wires and check the temperature performance of the sensor.

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— If the reading is still wrong, the transmitter electronics have failed. Replace

the sensor board stack.

LinE FAIL

LinE FAIL almost always means the transmitter is measuring an incorrect distance

between terminal TB-3 (resistance temperature device [RTD] return) and TB-4 (RTD sense). These terminals are critical connections for the three-wire RTD measurement.

Figure 8-3 shows a three-wire RTD connection.

Recommended actions

1. Check for miswires and open connections at TB-3 and TB-4. Open connections can be caused by loose connections, poor spade crimps, or broken wires. Be sure the check junction boxes for proper pass through of all wires.

• If correcting a wiring problem makes the message disappear, the system is in

good condition.

• If the message is still showing, go to Step 2.

2. The RTD sense or the RTD return wire inside the sensor cable may be broken. Keep the sensor wires attached and jumper TB-3 and TB-4.

• If the diagnostic message disappears, either the RTD return or RTD sense wire is

broken. To verify a broken wire, disconnect the leads and measure the resistance between them. Installing the jumper completes the circuit, but bypasses the three-wire function. The transmitter no longer corrects for changes in lead wire resistance with temperature. replace the sensor as soon as possible.

• If the diagnostic message remains, go to Step 3.

3. The cable connecting the sensor to the transmitter may be too long. Test using a sensor with a shorter cable.

• If shortening the cable eliminates the problem, move the transmitter closer to

the sensor. It may also be possible to increase diameter of the RTD wires. Consult the factory for assistance.

• If the diagnostic message remains, go to Step 4.

4. Check the temperature of the transmitter. Simulate both temperature and pH. See

tEMP HI and tEMP LO (steps 2 and 3) for temperature simulation and Simulating inputs - pH for pH simulation.

• If the transmitter fails either simulation, the electronic board stack should be

replaced.

• If the transmitter passes the simulations, the transmitter is not in good

condition, and the sensor should be replaced.

InPUt WArn

InPUt WArn means that the input value or the calculated pH is outside the measurement

range. The measured pH is less than -2 or greater than 16.

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Recommended actions

1. Check for miswires and open connections, particularly at TB-10. Open connections can be caused by loose connections, poor spade crimps, or broken wires. Be sure to check junction boxes for proper pass through of all wires.

• If correcting a wiring problem clears the message, the system is in good

condition.

• If the message is still showing, go to Step 2.

2. Check that the transmitter is working properly by simulating a pH input. See Testing

the transmitter by simulating the pH.

• If the transmitter does not respond to simulated inputs, replace the board stack.

• If the transmitter performs satisfactorily and the preamplifier is located in a

remote junction box or in a sensor-mounted junction box, go to Step 3.

• If the transmitter performs properly and the preamplifier is located in the

transmitter, the sensor has failed and should be replaced.

3. The problem may lie with the remote preamplifier or with the cable connecting the preamplifier and junction box to the transmitter.

a) Be sure all wires between the junction box and transmitter are connected.

b) Use Rosemount cable.

Generic cable may not work.

• If the disagnostic message clears, the interconnecting cable was the problem.

• If the message remains, go to Step 4.

4. Confirm that the problem is with the remote preamplifier.

a) Wire the pH sensor directly to the transmitter.

b) Change the menu from PAMP=SnSr to trAnS for the test and return it to SnSr

afterwards.

• If the error message clears, the remote preamplifier is faulty. Replace the

preamplifier.

• If the error message remains, the sensor has failed. Replace the sensor.

SLOPE Err LO

SLOPE Err LO means that a two-point buffer calibration attempt has failed. The slope is

too low (<40 mV/pH) for a good measurement.

Recommended actions

1. Repeat the calibration.

a) Inaccurate buffers can cause a low slope. Repeat the calibration using fresh

buffers. Alkaline buffers, pH 10 or greater, are particularly susceptible to changing value in air or with age. If you used a high pH buffer in the failed calibration, try a lower pH buffer when repeating the calibration. For example, use pH 4 and 7 buffer instead of pH 7 and 10 buffer.

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b) Allow adequate time for readings in buffer to become constant. If the sensor

was in a process substantially colder or hotter than the buffer, allow at least 20 minutes for readings in the buffer to stabilize. Alternatively, place the sensor in a container of water at ambient temperatures for 20 minutes before starting the calibration.

c) Be sure the correct buffer values are being entered during calibration.

• If the second calibration was successful, an error was made during the first

attempt.

• If the second calibration fails, go to Step 2.

2. Check wiring. Connections to TB-10, TB-7, and TB-8 are particularly important. Recalibrate the sensor.

• If the wiring was the only problem, the sensor should calibrate.

• If the message persists, go to Step 3.

3. Inspect and clean the sensor. Recalibrate the sensor.

• If the sensor was dirty, it should calibrate after cleaning.

• If the message persists, go to Step 4.

4. Check for a faulty sensor.

• If a spare sensor is available, connect it to the transmitter. Use the auto

calibration procedure to calibrate the sensor.

— If the new sensor cannot be calibrated, the transmitter is faulty. Go to Step 5.

— If the new sensor can be calibrated, the old sensor has failed.

• If a spare sensor is not available, measure the glass impendance (GIMP). See

Testing the transmitter by simulating the pH.

— If the glass impedance is less than about 20 megohms, the glass has cracked

and the electrode must be replaced.

— If the glass impedance is greater than about 20 megohms, the sensor is

probably in good condition. Go to Step 5.

5. Check transmitter performance by simulating pH inputs. See Testing the

transmitter by simulating the pH.

• If the transmitter performs satisfactorily, go to Step 6.

• If the transmitter does not respond to stimulated inputs, replace the board

stack.

6. If the transmitter responds to simulated inputs, the problem must lie with the sensor or the interconnecting wiring. Verify the interconnecting wiring point to point. Fix or replace bad cable. If the cable is good, replace the pH sensor.

SLOPE Err HI

SLOPE Err HI means that a two-point buffer calibration attempt has failed. The slope is

too high (> 62 mV/pH) for a good measurement.

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Recommended actions

1. Repeat the calibration.

a) Inaccurate buffers can cause a high slope. Repeat the calibration using fresh

b) Allow adequate time for readings in buffer to become constant. If the sensor

c) Be sure the correct buffer values are being entered during calibration. To

minimize errors caused by entering the wrong buffer values, use the autocalibration procedure.

d) Verify that the temperature reading is accurate. Compare the sensor reading

against a thermometer known to be accurate. Recalibrate if necessary.

• If the second calibration was successful, an error was made during the first

attempt.

• If the second calibration fails, go to Step 2.

2. There is a remote possibility of a problem with the autocalibration program. Repeat the calibration using the manual calibration procedure.

• If manual calibration was successful when autocalibration failed, the problem

might be with the sensor electronics. Call the factory for assistance.

• If manual calibration is not possible, go to Step 3.

3. Check the transmitter performance by simulating pH inputs. See Testing the

transmitter by simulating the pH.

• If the transmitter performs satisfactorily, go to Step 4.

• If the transmitter does not respond to stimulated inputs, replace the board

stack.

4. If the transmitter responds to simulated inputs, the problem must lie with the sensor or the interconnecting wiring. Verify the interconnecting wiring point to point. Fix or replace bad cable. If cable is good, replace the pH sensor.

Std Err

Std Err means the reference electrode voltage has changed drastically. Typical causes

are exposure to poisoning agents, sulfides or cyanides, or prolonged exposure to high temperature.

Troubleshooting depends on the type of sensor.

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Recommended actions

1. If the sensor is rebuildable, replenish the electrolyte solution and replace the liquid junction. Calibrate the sensor.

• If the sensor can be calibrated, the problem has been corrected.

• If the sensor cannot be calibrated, replace the sensor. If the sensor has separate

measuring and reference electrodes, replace only the reference electrode.

2. If the sensor is not rebuildable, try the reference electrode rejuvenation procedure.

• If the rejuvenated sensor can be calibrated, the problem has been corrected.

• If the sensor cannot be calibrated, replace the sensor.

rOM FAIL or CPU FAIL

rOM FAIL or CPU FAIL means the transmitter electronics have failed.

Recommended action

Replace the electronic board stack (PN 23992-02 [-HT] or PN 23992-03 [-HF]).

AdC WArn or CyCLE PWr

The Adc WArn or CyCLE PWr message appears momentarily when the transmitter has recognized an internal calculation problem. The transmitter repeats the calculation, and

the message disappears once the calculation is successful. If the message is displayed constantly, the transmitter electronics may be faulty.

Recommended actions

1. Check transmitter performance by simulating pH inputs. See Testing the

transmitter by simulating the pH.

• If the transmitter performs satisfactorily, go to Step 2.

• If the transmitter does not respond to simulated inputs, replace the board stack.

2. If the transmitter responds to simulated inputs, the problem must lie with the sensor or the interconnecting wiring. Verify the interconnecting wiring point to point. Fix or replace bad cable. If cable is good, replace the pH sensor.

WritE Err

WriTE Err means that jumper JP1 on the CPU board is not in place. If the sensor is not in

place, the transmitter cannot be programmed or calibrated.

Recommended actions

1. Check the position of jumper JP1 on the CPU board. If the jumper is hanging off one of the pins, place it across both pins. If the jumper is missing entirely, use jumper JP3 (50/60 Hz), which is not a critical jumper.

There are similar numbered jumpers on the analog board. The jumper to be checked is on the CPU board, which is the center board in the stack.

2. Turn the power to the transmitter off and then back on.

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• Toggling the power should cause the message to disappear.

• If the message does not disappear, replace the electronic board stack.

FACt FAIL

FACt FAIL means the unit has not been factory calibrated. Call the factory. The

transmitter will probably need to be returned to the factory for calibration.

8.2.4 Troubleshooting when no diagnostic message is showing

If no diagnostic message is showing, locate the symptom(s) in the table below and refer to the appropriate section for assistance.

Symptom Section

Id000 appears in display when trying to

program or calibrate transmitter

Error message flashing in display Troubleshooting when a diagnostic message is

Transmitter does not respond to remote controller

Calibration problems

SLOPE Err HI or SLOPE Err LO appears

after calibration attempt

bF1 or bF2 continuously flashes during auto

calibration

pH reading in buffer drifts during manual calibration

Measurement problems

Sensor does not respond to known pH changes Sensor does not respond to known pH changes

Buffer calibration is acceptable; process pH is slightly different from expected value

Buffer calibration is acceptable; process pH is grossly wrong and/or readings are noisy

Temperature reading is inaccurate Temperature reading is inaccurate

Id000 in display

showing

Transmitter not responding to IRC

SLOPE Err LO or SLOPE Err Hi appear after calibration attempt

bF1 or bF2 continuously flashes during autocalibration

pH reading in buffer drifts during manual calibration

Buffer calibration is acceptable; process pH is slightly different from expected value.

Buffer calibration is acceptable; process pH is grossly different from expected value

Transmitter problems

No display No display

Display segments missing or display incorrect Display segments missing

Transmitter locked up, all display segments lit Transmitter locks up

Transmitter periodically restarts itself Transmitter periodically restarts itself

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Id000 in display

A security code has been programmed into the transmitter. The correct code must be entered before the transmitter can be programmed or calibrated.

Transmitter not responding to IRC

Recommended actions

1. Be sure the transmitter is receiving the signal. a) Clean the window in front of the IR detector.

The detector is a small rectangle just above the main display.

b) Hold the IRC at least 6 ft. (1.8 m) from the transmitter and not more than 15

degrees from the center.

c) Hold the IRC closer (within 2 ft. [.6 m]) in case the batteries are getting weak.

2. If Step 1 fails, check the IRC. a) If a second transmitter is available, test the IRC on that transmitter. If a spare

transmitter is not available, continue with Step b.

b) The green LED, located just above and between the RESET and HOLD

buttons, should light when a key is pressed. A piece of black rubber film may be covering the LED. Scrape the film away with your fingernail to expose the LED.

The two clear LEDs on the front end of the IRC never light. They transmit the invisible IR signal.

c) If the green LED does not light, the IRC is not working. Go to Step 3.

3. Take the IRC to a non-hazardous area and replace the two 1.5 Vdc AAA batteries.

• If the green LED lights, but the transmitter still does not respond, go to Step 4.

• If neither the LED lights nor the transmitter responds, replace the IRC.

4. Replace the transmitter display board.

SLOPE Err LO or SLOPE Err Hi appear after calibration attempt

Refer to SLOPE Err LO and SLOPE Err HI for assistance in solving calibration slope problems.

bF1 or bF2 continuously flashes during autocalibration

During autocalibration, bF1 or bF2 flashes until the pH reading of the sensor in the buffer is stable.

Recommended actions

1. Check the stability limits.

If the stabilization range (prompt PH) is set too narrow or the stabilization time (prompt tIME) is set too long, the transmitter will not accept buffer readings. A good choice for PH is 0.02, and a good choice for tIME is 10 - 20 seconds.

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2. Allow adequate time for the temperature of the sensor to reach the temperature of

the buffer. If the sensor was in a process substantially hotter or colder than the buffer, allow at least 20 minutes for readings in the buffer to stabilize. Alternatively, place the sensor in a container of water at ambient temperature for 20 minutes before starting the calibration.

3. Be sure to swirl the sensor after placing it in each new buffer solution.

4. Finally, check the sensor. Verify that wiring is correct. Also, the sensor may be dirty

or aged, or the reference junction may be depleted.

a) Check that the sensor is properly wired to the transmitter.

Pay particular attention to terminals TB-10 (mV in), TB-7 (reference), and TB-8 (solution ground).

b) Clean the sensor.

c) If the sensor is not rebuildable, rejuvenate the reference junction.

d) If the sensor is rebuildable, replenish the reference electrolyte and replace

the liquid junction.

e) Replace the sensor.

A clean pH sensor should not drift in buffer.

pH reading in buffer drifts during manual calibration

Recommended actions

1. Allow adequate time for the temperature of the sensor to reach the temperature of

2. Be sure to swirl the sensor after placing it in each new buffer solution.

3. Finally, check the sensor. Verify that wiring is correct. Also, the sensor may be dirty

or aged, or the reference junction may be depleted.

a) Check that the sensor is properly wired to the transmitter.

Pay particular attention to terminals TB-10 (mV in), TB-7 (reference), and TB-8 (solution ground).

b) Clean the sensor.

c) If the sensor is not rebuildable, rejuvenate the reference junction.

d) If the sensor is rebuildable, replenish the reference electrolyte and replace

the liquid junction.

e) Replace the sensor.

A clean pH sensor should not drift in buffer.

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Sensor does not respond to known pH changes

Recommended actions

1. Verify that the change really happened. If you were checking pH response in

buffers, recheck performance with fresh buffers. If a process pH reading was not what was expected, check the performance of the sensor in buffers. Also, use a second pH meter to verify that the expected change in the process pH really occurred.

2. Check the sensor. Verify that wiring is correct. Also, the sensor may be dirty or aged,

or the reference junction may be depleted. Check that the sensor is properly wired to the transmitter.

See Wire. Pay particular attention to terminals TB-10 (mv in), TB-7 (reference), and TB-8 (solution ground).

3. If a clean, properly wired sensor does not respond to pH changes, the glass bulb is

probably broken or cracked.

a) If a spare sensor is available, check the spare.

If the spare sensor responds to pH changes, the old sensor has failed.

If the spare sensor does not respond to pH changes, go to Step 4.

b) If a spare sensor is not available, check the glass impedance (GIMP) of the

existing sensor. If the impedance is less than about 20 megohm, the pH sensor is cracked. Replace the sensor.

If the impedance is greater than about 20 megohm, go to Step 4.

4. Check transmitter performance by simulating pH inputs.

See Testing the transmitter by simulating the pH. If the transmitter responds to simulated inputs, the problem must lie with the

sensor or the interconnecting wiring. Verify the interconnecting wiring point to point. Fix or replace bad cable. If cable is good, replace pH sensor.

If the transmitter does not respond to simulated inputs, replace the board stack.

Buffer calibration is acceptable; process pH is slightly different from expected value.

Differences between pH readings made with an on-line instrument and a laboratory or portable instrument are normal. The on-line instrument is subject to process variables (for example, ground potentials, stray voltages, and orientation effects) that do not affect the laboratory or portable instrument.

Buffer calibration is acceptable; process pH is grossly different from expected value

The systems suggest a ground loop (measurement system connected to earth ground at more than one point), a floating system (no earth ground), or noise being induced into the transmitter by a sensor cabling.

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The problem arises from the process or installation. It is not a fault of the transmitter. The problem should disappear once the sensor is taken out of the system.

Recommended actions

1. To confirm a ground loop: a) Verify that the system works properly in buffers. Be sure there is no direct

electrical connection between the buffer containers and the process liquid or piping.

b) Strip back the ends of a heavy gauge wire. Connect one end of the wire to the

process piping or place it in the process liquid. Place the other end of the wire in the container of buffer with the sensor.

The wire makes an electrical connection between the process and sensor.

If similar symptoms develop after making the connection, a ground loop exists. If no symptoms develop, a ground loop may or may not exist.

2. Check the grounding of the process.

The measurement system needs one path to ground: through the process liquid and piping. Plastic piping, fiber glass tanks, and ungrounded or poorly grounded vessels do not provide a path. A floating system can pick up stray voltages from other electrical equipment.

a) Ground the piping or tank to a local earth ground.

Metal tees, grounding rings, or grounding rods may be required.

b) If problems persist, connect a wire from the ground connection at the dc

power supply to the transmitter case. Connect a second wire from the transmitter case to the process. These connections force the grounds to the same potential.

If the problem persists, simple grounding is not the problem. The sensor wiring is probably carrying noise into the instrument. Go to Step 3.

3. Simplify the sensor wiring. a) Disconnect all sensor wires at the transmitter except: TB-4 (resistance

temperature device [RTD] sense), TB-5 (RTD IN), TB-7 (Reference IN), and TB-10 (pH/ORP IN). If you are using a remote preamplifier, disconnect the wires at the input side of the junction box.

b) Tape back the ends of the disconnected wires, including all shield and drain

wires, to keep them from making accidental connections with other wires, terminals, or the transmitter case.

c) Connect a jumper wire between TB-3 (RTD return) and TB-4 (RTD sense).

Connect a second jumper wire between TB-7 (Reference IN) and TB-8 (Solution ground).

d) Place the sensor back in the process liquid. If diagnostic measures such as

GLASSFAIL or REF WArn appear, turn off the sensor diagnostics.

If the symptoms disappear, interference was coming into the transmitter along one of the sensor wires. The measurement system can be operated permanently with simplified wiring.

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If symptoms still persist, go to Step 4.

4. Check for extra ground connections or reduced noise.

The electrode system is connected to earth ground through the process. If other ground connections exist, there are multiple paths and ground loops are present. Noise enters the measurement either by a direct connection, usually between the cable and grounded metal, or by an indirect connection, usually EMI/RFI picked up by the cable.

a) If the sensor cable is run inside conduit, there may be a short between the

cable and the conduit. Re-run the cable outside the conduit. If symptoms disappear, then a short exists between the table and the conduit. Likely a shield is exposed and is touching the conduit. Repair the cable and reinstall it in the conduit.

b) To avoid induced noise in the sensor cable, run it as far away as possible from

the power cables, relays, and electric motors. Keep sensor wiring out of crowded panels and cable trays.

c) Occasionally, noise can travel into the transmitter housing from the metal it

is mounted on. The noise is then radiated into the transmitter electronics. If isolating the transmitter from its metal mounting eliminates the symptoms, move the transmitter to a different location or mount it with isolating materials.

If ground loop problems persist, consult the factory. It may require a visit from an experienced service technician to solve plant-induced problems.

Temperature reading is inaccurate

Recommended actions

1. To troubleshoot temperature problems, refer to tEMP HI and tEMP LO.

2. Calibrate the temperature response of the sensor.

3. If necessary, automatic temperature compensation can be temporarily disabled

and the transmitter placed in manual temperature compensation. For manual temperature, choose a temperature equal to the average temperature of the process. The resulting pH reading will be in error. The more variable the temperature and the further from pH 7, the greater the error.

HART® communication problems

Recommended actions

1. If the handheld communicator software does not recognize the =transmitter, order

an upgrade from Rosemount at 800 999 9307.

2. Be sure the HART load and voltage requirements are met.

• HART communications requires a minimum 250 ohm load in the current loop.

• Install a 250 - 500 ohm resistor in series with the current loop. Check the actual

resistor value with an ohmmeter.

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• For HART communications, the power supply voltage must be at least 18 Vdc.

3. Be sure the HART communicator is properly connected.

• The communicator leads must be connected across the load.

• The communicator can be connected across the power terminals (TB-15 and

TB-16).

4. Verify that the handheld communicator is working correctly by testing it with another HART Smart device. If the communicator is working, the transmitter electronics may have failed. Call Rosemount for assistance.

If the communicator seems to be malfunctioning, call Rosemount at 800 999 9307 for assistance.

No display

Recommended actions

1. Be sure power requirements are being met.

a. The positive voltage lead must be connected to TB-16.

b. Check dc voltage requirements and load restrictions.

2. Check for bad connections between the circuit boards. Be sure the ribbon cable between the display and CPU boards is firmly seated in the socket on the CPU board. Be sure the socket connection between the CPU and analog boards is firm.

Display segments missing

Recommended action

Replace the display board.

Transmitter locks up

Recommended actions

1. Turn the dc power off; then turn it back on.

2. If the problem persists, replace the electronic board stack (HART®: PN 23992-02; FOUNDATION™ Fieldbus: PN 23992-03).

Transmitter periodically restarts itself

Recommended actions

1. The problem is usually related to improperly wired resistance temperature device (RTD) input terminals.

a) The RTD return wire must be connected to TB-3. The RTD sense wire must be

connected to TB-4, and the RTD in wire must be connected to TB-5. If the pH sensor does not have an RTD, connect a jumper wire across the terminals TB-3 and TB-4 and a second jumper across TB-4 and TB-5.

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b) If you have jumpered the RTD connections as described in 1.a, turn off

automatic temperature compensation and operate the transmitter in manual temperature mode.

2. If RTD wiring is correct and problems still persist:

a) Monitor the power supply. Be sure the power is not intermittent and the

correct voltage is present.

b) Try connecting the transmitter to a different power supply.

8.2.5 Displaying diagnostic variables

This section describes how to display the diagnostic variables listed below:

Diagnostic measurements

1. Sensor voltage in mv (InPut)

2. Glass impedance in megohms (GIMP)

3. Reference temperature in kilohms (rIMP)

(1)

4. Temperature in °C

Diagnostic messages

1. Software version (VEr)

2. Display last three fault messages (ShoW FLt)

Note

Displays are read only.

Procedure

1. Press DIAG on the IRC to enter the Diagnostic menu. Sensor voltage in mV (InPut) appears.

2. Press NEXT. The temperature corrected glass impedance in megohms (GIMP) appears.

3. Press NEXT. The reference impedance (rIMP) appears. For conventional low impedance silver/ silver chloride reference electrodes, the reference impedance has units of kilohms. For the rare occasions when a high impedance reference is used, the units are megohms.

4. Press NEXT. The model number and software version (Ver) appears.

5. Press NEXT. The temperature (tEMP) measured by the sensor appears.

6. Press NEXT. The ShoW Fit submenu appears.

For high impedance reference electrodes, the reference impedance is in megohms.

(1)

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7. Press ENTER. The most recent fault message appears in the display.

8. Press NEXT repeatedly to scroll through the stored messages. The transmitter only remembers the three most recent messages. nonE appears if there are no faults. Press EXIT to clear all the stored messages and return the transmitter to the ShoW Fit display. If the transmitter loses power, all stored warnings and fault messages are lost.

9. Press EXIT to return to the process display.

8.2.6 Testing the transmitter by simulating the pH

Overview of simulating a pH input

This section describes how to simulate a pH input into the Rosemount 5081-P pH/ORP transmitter. pH is directly proportionsl to voltage.

To simulate the pH measurement, connect a standard millivolt source to the transmitter. If the transmitter is working properly, it will accurately measure the input voltage and convert it to pH. Although the general procedure is the same, the wiring details depend on the location of the preamplifier. Consult the table to find the correct procedure.

Preamplifier located in Section

Transmitter Simulate pH when the preamplifier is located in the transmitter

Remote junction box Simulate pH when the preamplifier is located in a remote junction box or in a

sensor-mounted junction box

Sensor-mounted junction box Simulate pH when the preamplifier is located in a remote junction box or in a

sensor-mounted junction box

Sensor Simulate pH when preamplifier is in sensor

Simulate pH when the preamplifier is located in the transmitter

Procedure

1. Program PAMP to transmitter.

2. Turn off sensor diagnostics.

3. Turn off automatic temperature compensation. Set manual temperature compensation to 77 °F (25 °C).

4. Disconnect the sensor and wire transmitter as shown in Figure 8-5.

5. Attach a jumper between TB-7 (Reference IN) and TB-10 (pH IN).

6. Measure the voltage. Press DIAG on the infrared remote control (IRC). The InPut voltage in millivolts appears in the temperature-output area. The main display continues to show pH. The measured voltage should be 0 mV, and the pH should be approximately 7. Because the calibration data in the transmitter may be offsetting the input voltage, the displayed pH may not be exactly 7.0. If the actual readings are close to expected, the transmitter is probably operating normally.

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7. If a standard millivolt source is available, remove the jumper between TB-7 and TB-10 and connect the voltage source.

8. Calibrate the transmitter. Use 0.0 mV for pH 7 (bF1) and -177.4 mV for pH 10 (bF2). If the transmitter is working, it should accept the calibration.

9. To check linearity, leave autocalibration and return to the main display. Set the voltage source to the values in the table and verify that the pH reading matches the expected value.

Voltage (mV) pH

295.8 2.00

118.3 5.00

-118.3 9.00

-295.8 12.00

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Example

Figure 8-5: pH simulation when the preamplifier is located in the transmitter

A. Transmitter B. Earth ground C. Shield

D. Resistance temperature device (RTD) return

E. -RTD sense

F. RTD in G. Reference ground H. Reference in

I. Solution ground J. pH guard

K. pH in

L. +RTD sense

M. mV source

Simulate pH when the preamplifier is located in a remote junction box or in a sensor-mounted junction box

Procedure

1. Program PAMP to sensor.

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2. Turn off sensor diagnostics.

3. Turn off automatic temperature compensation. Set manual temperature compensation to 77 °F (25 °C).

4. Disconnect the sensor and wire the sensor side of the junction box as shown in

Figure 8-5. Leave the interconnecting cable between the junction box and

transmitter in place.

5. Attach a jumper between TB1-7 (Reference IN) and TB1-10 (pH IN)

6. From this point on, continue with steps 6 through 9 in Simulate pH when the

preamplifier is located in the transmitter.

For testing using a standard millivolt source. Be sure to remove the jumper between TB1-7 and TB1-10 before connecting the standard millivolt source.

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Example

Figure 8-6: pH simulation when the preamplifier is located in a remote junction box or in a sensor mounted junction box

A. Remote junction box: PN 23555-00 (includes preamplifier). Board PN 23557-00 B. mV source C. Jumpers

D. No connection

E. Normally closed

F. Far side G. Extension cable point to point wiring terminals 2 to 12 H. Earth ground

I. Shield J. Resistance temperature device (RTD) return

K. -RTD sense

L. RTD in

M. Reference ground

N. Solution ground O. pH guard

P. pH in Q. +RTD sense

R. Transmitter

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Simulate pH when preamplifier is in sensor

The preamplifier in the sensor simply converts the high impedance signal into a low impedance signal without amplifying it.

8.3 Contacting and toroidal conductivity diagnostics and troubleshooting

8.3.1 Diagnose menu

The transmitter automatically monitors for fault conditions. The Diagnose menu displays current variable settings and fault messages. The messages are defined in Table 8-2.

Troubleshoot contacting conductivity analyzers

Procedure

1. Look for a diagnostic fault message on the display to help pinpoint the problem. Refer to Diagnostic messages for an explanation of the message recommended

actions to solve it.

2. Refer to Troubleshooting when no diagnostic message is showing for common loop problems and the recommended actions to resolve them.

Display diagnostic values

Use the DIAG key on the IRC is used to access the Diagnose menu. The messages are defined in Table 8-2.

Use the FAuLtS submenu to show the last three faults/warnings. The most recent is displayed first. Use NEXT to scroll through the remaining faults. Press EXIT to clear all fault/warnings and returns the FAuLtS segment. Disconnecting the transmitter removes all fault messages from memory. The nonE message is displayed when no faults/warnings

have occurred.

Table 8-2: Diagnostic variables mnemonics

AbS Absolute conductivity (µS/cm or mS/cm)

0 A ir Sensor zero in air

CELL ConSt Sensor cell constant (used in C mode)

tSLOPE Temperature slope in %/° C

CAL F Calibration factor

SoFt Software version

HArd Hardware version

FAuLtS Show fault messages

nonE No fault messages in memory

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8.3.2 Fault conditions

The diagnostic program detects and diffentiates three classes of error conditions/ problems. System disabling problems are faults caused by failures in the loop or significant variations in the process. System non-disabling problems are warnings and deal with input or A to D conversion settings. The third class of detection problems are error messages and occur when the calibration limits are exceeded.

Disabling faults

When a disabling fault occurs:

1. Both FAULT and HOLD annunciation fields become active (Figure 8-7).

2. The process variable flashes at the rate of 1 second on and 1 second off.

3. The appropriate fault message alternates with the normal Temperature/Current output display (see Figure 8-7).

4. The output current loop is forced to run the non-zero fault value last entered or held at last value if fault value = 0 if the transmitter is not in the TEST, HOLD, or Multidrop operational modes.

5. A 0-1 mA output signal is available for external use when system disability conditions are active. These conditions drive this output to 1 mA. Please contact factory for specific application information.

Figure 8-7: Disabling Fault Annunciation

Non-disabling warnings

When a non-system-disabling condition occurs, a warning message is displayed.

The process variable does not flash. The appropriate message alternates with the Temperature/Current output display (see Figure 8-8).

If more than one fault exists, the display will sequence through each diagnostic message. This will continue until the cause of the fault has been corrected.

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Figure 8-8: Warning Annunciation

8.3.3 Diagnostic messages

The transmitter's diagnostics constantly monitor the conductivity loop for possible problems. If an operational problem is encountered, check the display for a fault or error message. These are displayed in the Temperature/Current output segment of the display. Note the message and refer to the following sections for a description of possible problems that may have triggered the diagnostic message.

Faults

tEmP LO

Temperature is too low.

Recommended actions

1. Check wiring or sensor/process temperature.

2. Check resistance temperature device (RTD).

tEmP HI

Temperature is too high.

Recommended actions

1. Check wiring or sensor/process temperature.

2. Check resistance temperature device (RTD).

rtd FAIL

The resistance temperature device (RTD) sensor line fault limits have been exceeded into the sensor.

Recommended action

Check wiring or check Program/Temp menu setting to verify the 100-3 or 100-4 sensor type connected.

CPU FAIL

The CPU has failed during RAM or EEPROM verification.

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Recommended action

Recycle. If persistent, contact the factory.

FACt FAIL

FACt FAIL appears if the transmitter factory calibration message has been triggered.

A stray noise spike can cause this message to appear.

Recommended actions

1. If the pH reading seems acceptable, reset the calibration flag.

a) Press 2 on the infrared remote control (IRC) ten times to enter the factory

calibration menu. The display does not change.

b) Press 3.

FActorYCAL appears in the display.

c) Press NEXT.

rEPAir appears in the display.

d) Press NEXT.

ConFIG appears in the display.

e) Press NEXT.

rESEt appears in the display.

f) Press NEXT.

rESEtCFG appears in the display.

g) Press ENTER.

rESET appears again.

h) Press NEXT.

FActorYCAL reappears.

i) Press ENTER.

FactOn appears in the display.

j) Press 3.

FactOFF appears.

k) Press ENTER to store the settings.

l) Press EXIT repeatedly until the main display reappears.

If the message does not clear or problems persist, the electronics have failed. Replace the electronic board stack.

2. Contact factory.

rOm FAIL

The PROM failed the check-sum test.

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Recommended action

Contact factory.

CyCLE PoWr

A wrong value was detected during power-up.

Recommended action

Recycle the power.

SEnSor FAIL

Bad sensor means that the sensor current is a large negative number. SEnSor FAIL may appear for a while when the sensor is first placed in service.

Recommended actions

1. Observe the sensor. Go to SEnSor Cur under the Diagnostic menu. If the sensor is moving in the positive direction, there is probably nothing wrong. The error message should soon disappear.

2. Verify that wiring is correct. Pay particular attention to the anode and cathode connections.

3. Verify that the transmitter is configured for the correct measurment. Configuring the measurement sets several things, including the polarizing voltage.

Applying the wrong polarizing voltage to the sensor can cause a negative current.

4. Replace the sensor membrane and electrolyte solution and clean the cathode if necessary.

See the sensor reference manual for details.

5. Replace the sensor.

Warnings

InPUt WArn

InPUt WArn means that the input value or the calculated pH is outside the measurement

range. The measured pH is less than -2 or greater than 16.

Recommended actions

• If correcting a wiring problem clears the message, the system is in good

condition.

• If the message is still showing, go to Step 2.

2. Check that the transmitter is working properly by simulating a pH input. See Testing

the transmitter by simulating the pH.

• If the transmitter does not respond to simulated inputs, replace the board stack.

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• If the transmitter performs satisfactorily and the preamplifier is located in a

remote junction box or in a sensor-mounted junction box, go to Step 3.

• If the transmitter performs properly and the preamplifier is located in the

transmitter, the sensor has failed and should be replaced.

3. The problem may lie with the remote preamplifier or with the cable connecting the preamplifier and junction box to the transmitter.

a) Be sure all wires between the junction box and transmitter are connected.

b) Use Rosemount cable.

Generic cable may not work.

• If the disagnostic message clears, the interconnecting cable was the problem.

• If the message remains, go to Step 4.

4. Confirm that the problem is with the remote preamplifier.

a) Wire the pH sensor directly to the transmitter.

b) Change the menu from PAMP=SnSr to trAnS for the test and return it to SnSr

afterwards.

• If the error message clears, the remote preamplifier is faulty. Replace the

preamplifier.

• If the error message remains, the sensor has failed. Replace the sensor.

OvEr rAnGE and AMP FAIL

The current range setting has been exceeded or the measurment exceeds the display limit.

This error message appears if the sensor current is too high. Normally, excessive sensor current implies that the sensor is miswired or the sensor has failed.

Recommended actions

1. Verify the 4 and 20 mA settings in the Program/output menu.

2. Verify that the wiring is correct and connections are tight. Be sure to check connections at the junction box if one is being used.

3. Replace the sensor membrane and electrolyte solution and clean the cathode if necessary.

See the sensor reference manual for details.

4. Replace the sensor.

AdC Error

AdC Error means the analog to digital converter has failed.

Recommended actions

1. Verify that the sensor wiring is correct and connections are tight. Be sure to check connections at the junction box if one is being used.

2. Disconnect sensor(s) and simulate temperature and sensor input.

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If the transmitter does not respond to simulated signals, the analog PCB has probably failed.

3. Recycle the power.

4. Call the factory for assistance.

nEEd 0 CAL

The message nEEd 0 CAL means that the concentration of the analyte is too negative.

Recommended actions

1. Check the zero current (go to 0 CurrEnt under the Diagnose menu). If the zero current is appreciably greater than the measurement current, the nEEd

0 CAL warning appears.

2. Verify that the zero current is close to the value given in the calibration section for the analyte being determined.

3. Rezero the sensor. Refer to the calibration and troubleshooting sections of the sensor reference

manual for more information.

Errors

CAl Err or OFFSEt Err

A calibration error has occurred between the standard and process.

Recommended action

Press RESET and repeat. Check calibration standards and unit configuration.

tSLOPE Err

The limit for T-2 in a two point calibration has been exceeded.

Recommended action

Press RESET and repeat the calibration/temp. slope menu setting.

-0- Err

Sensor zero limit has been exceeded.

Recommended actions

Press RESET and repeat the calibrate/sensor menu setting.

WritE Err

An attempt to write on the EEPROM has failed.

The jumper JP-1 on the CPU board has been removed.

SenSE OPEn

Most Rosemount sensors use a Pt100 or Pt1000 in a three-wire configuration. The in and return leads connect the resistance temperature device (RTD) to the measuring circuit in the transmitter. A third wire, called the sense line, is connected to the return lead. The

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sense line allows the transmitter to correct for the resistance of the in and return leads and to correct for changes in lead wire resistance with changes in ambient temperature.

Recommended actions

1. Verify all wiring connections, including wiring in a junction box if one is being used.

2. Disconnect the RTD SENSE and RTD RETURN wires. Measure the resistance between the leads.

It should be less than 5 Ω.

3. If the sense line is open, replace the sensor as soon as possible. The transmitter can be operated with the sense line open. The measurement will be

less accurate, because the transmitter can no longer compensate for lead wire resistance. However, if using the sensor at approximately constant ambient temperatures, you can eliminate the lead wire resistance error by calibrating the sensor to the measurement temperature. Errors caused by changes in ambient temperature cannot be eliminated.

4. To make the error message disappear, connect the RTD SENSE and RETURN terminals with a jumper.

8.3.4

Troubleshooting when no diagnostic message is showing

The following sections identify some of the more common symptoms and suggest actions to help resolve a problem. In general, wiring is the most common cause.

Wrong temperature reading

Recommended actions

1. Perform a temperature standardization.

2. Verify sensor's resistance temperature device (RTD).

Suspected temperature compensation problem

Recommended action

Check wiring.

Display segments missing

Recommended action

Replace the display board.

Transmitter locks up

The transmitter won't respond

Recommended actions

1. Replace PCB stack.

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2. Press RESET.

3. Check batteries in infrared remote control (IRC).

Erratic displays

Recommended action

Check sensors in process.

Transmitter won't respond to infrared remote control (IRC) key presses

Recommended actions

1. Verify and clean ribbon cable connection on CPU board.

2. Check batteries in IRC.

Key press gives wrong selection

Recommended actions

1. Replace infrared remote control (IRC).

2. Check ribbon cable connection on CPU board.

Wrong or no current output

Recommended actions

1. Verify that output is not being overloaded.

2. Remove load.

3. Replace PCB stack.

No display or indicators

Recommended action

Replace PCB stack.

Excess input

Recommended action

Check sensor wiring.

Reverse input

Recommended action

Perform sensor zero.

Check sensor zero

The transmitter will not zero.

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Recommended action

Place the sensor in the air and access zero routine.

8.3.5 Troubleshoot in the field

When it is apparent by grab sample analysis that the transmitter is giving inaccurate readings, try the following:

Prerequisites

Make sure the sensor surfaces are totally wetted by the process and that air bubbles are not trapped in the vicinity of electrodes. If you find air bubbles, change the installation technique to eliminate air bubbles.

Procedure

1. Visually inspect the installation.

a) Check that the transmitter is mounted securely and that its internal parts are

properly connected.

b) Check all input and output wiring.

8.3.6

2. If Step 1 did not indicate the source of the problem, isolate the problem to either the transmitter or the sensor.

3. To troubleshoot the sensor:

a) Disconnect the sensor from the transmitter.

b) Remove the sensor from the process.

c) Thoroughly dry the sensor electrodes.

Refer to the sensor reference manual for additional troubleshooting checks.

4. To troubleshoot the transmitter independently of the sensor, use an appropriate resistor across the temperature input connectors and connect the conductivity inputs to resistance decade box.

Troubleshoot conductivity measurement

If troubleshooting in the field does not resolve the error, try the following procedure to troubleshoot a conductivity measurement problem in the process.

Note

Before starting this procedure, make sure that all wiring is correct.

Procedure

1. Remove the sensor from process and place the sensor in air. Zero the transmitter. This step is for normal contacting only, not for low conductivity or resistivity. If the transmitter zeros correctly, place the sensor in the process and standardize.

2. If the transmitter does not zero correctly:

a) Check diagnostic messages.

Refer to Diagnostic messages.

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b) Check wiring for short.

c) Consult service center.

3. If the sensor does not standardize:

a) Remove the sensor from the process and test it in a known conductivity

solution or against a certified conductivity instrument.

b) Check for ground loops and/or improper installation.

8.3.7 Resistance temperature device (RTD) resistance values

Table 8-3 is a ready reference of RTD resistance values at various temperatures. Use these

values to test and evaluate the sensor.

Note

Resistance values are read across the RTD element and are based on the manufacturer's stated values (±1%). Allow enough time for the RTD element in the sensor to stabilize to the surrounding temperature.

Table 8-3: RTD Resistance Values

Temperature Pt-100 resistance (ohms) Pt-1000 resistance (ohms)

32 °F (0 °C) 100.00 1000

50 °F (10 °C) 103.9 1039

68 °F (20 °C) 107.79 1078

77 °F (25 °C) 109.62 1096

86 °F (30 °C) 111.67 1117

104 °F (40 °C) 115.54 1155

122 °F (50 °C) 119.40 1194

140 °F (60 °C) 123.24 1232

158 °F (70 °C) 127.07 1271

176 °F (80 °C) 130.89 1309

194 °F (90 °C) 134.70 1347

212 °F (100 °C) 138.50 1385

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Figure 8-9: Conductivity Determination

Use the formula to determine the appropriate resistance value to use to simulate a conductivity value.

8.4 Chlorine, dissolved oxygen, and ozone diagnostics

8.4.1 Diagnostics overview

The Rosemount 5081 transmitter can display diagnostic information that is useful in troubleshooting. The diagnostics available depend on the measurement being made. To read diagnostic information, go to the main display and press DIAG on the infrared remote controller. Press NEXT until the desired diagnostic message appears. Refer to the appropriate section below for more information.

8.4.2

Diagnostic messages for dissolved oxygen

Message See section

TYPE O2 TYPE O2

SEnSor Cur SEnSor Cur

SEnSitvtY SEnSitviTY

0 CurrEnt 0 CurrEnt.

bAr PreSS bAr PreSS.

5081-A-Ht 5081-A-Ht.

FAULtS FAULtS

TYPE O2

Transmitter is measuring oxygen.

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Specifications and Main Features

Frequently Asked Questions

User Manual

Contents

1 Start-up

2 Description and specifications

2.1 Features and applications

2.2 General specifications

2.3 Rosemount 5081 - (A/P/C/T) product certifications

2.3.1 European Directive Information

2.3.2 Ordinary Location Certification

Installing equipment in North America

USA

2.3.5 Canada

2.3.6 Europe

Rosemount 5081-A and 5081-P liquid transmitters

Rosemount 5081-C liquid transmitter

Rosemount 5081-T liquid transmitter

International

2.4 Functional specifications

2.4.1 pH/ORP specifications

2.4.2 Contacting conductivity specifications

2.4.3 Toroidal conductivity specifications

2.4.4 Dissolved oxygen specifications

2.4.5 Free chlorine specifications

2.4.6 Total chlorine specifications

2.4.7 Ozone specifications

2.4.8 Percent oxygen in gas

2.5 Ordering information

3 Install

3.1 Unpack and inspect

3.2 Installation guidelines

3.3 Orient the display board

3.4 Mount on a flat surface

3.5 Mount on a pipe

4 Wire

4.1 Wiring overview

4.2 Power supply/current loop

4.2.1 Power supply overview

4.2.2 Wire to HART® or FOUNDATION™ Fieldbus communication protocol

5 Display and operate

5.1 User interface and main display

5.2 Infrared remote control (IRC)

5.3 Menu system

6 Programming basics

6.1 Programming

6.2 Test 4-20 mA outputs and current generated during hold and faults

6.3 Correct temperature

6.4 Set up a custom curve (conductivity measurements only)

6.5 Restore to factory default settings

6.6 Set access (security) code

6.6.1 Security overview

Enter the access (security) code

6.6.3 Retrieve a lost security code

6.7 Activate or deactivate HOLD

7 Measurements

7.1 Calibrating pH sensors

7.1.1 Calibration overview

Calibration standards (buffer solutions)

Auto-calibrate

Calibrate manually

Standardize for pH

7.2 Calibrating oxidation reduction potential (ORP) sensors

7.2.1 Oxidation reduction potential (ORP) overview

Calibrate temperature with an oxidation reduction potential (ORP) sensor

Standardize with an oxidation reduction potential (ORP) sensor

Match transmitter to oxidation reduction potential (ORP) sensor's temperature element

7.3 Calibrating contacting and toroidal conductivity sensors

7.3.1 Overview of calibrating contacting conductivity sensors

7.3.2 Calibrate contacting conductivity sensors

Zero the sensor

Adjust temperature

7.3.5 Calibrate in-process

7.3.6 Calibrate temperature slope

Calibrate output

7.4 Calibrating dissolved oxygen, ozone, free chlorine, total chlorine, and ozone sensors

7.4.1 Calibrating amperometric sensors

Zero the sensor

7.4.3 Calibrate in air (dissolved oxygen)