Michell Instruments MDM300-IS Operating Manual

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MDM300 I.S.

Advanced Dew-Point Hygrometer

User’s Manual

- I.S.

97213 Issue 5

October 2017

Please ﬁ ll out the form(s) below for each instrument that has been purchased.

Use this information when contacting Michell Instruments for service purposes.

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- I.S.

MDM300 I.S.

Advanced Dew-Point Hygrometer

(for use in hazardous areas)

For Michell Instruments' contact information please go to

www.michell.com

This document is the property of Michell Instruments Ltd. and may not be copied or

otherwise reproduced, communicated in any way to third parties, nor stored in any Data

Processing System without the express written authorization of Michell Instruments Ltd.

MDM300 I.S. User’s Manual

Contents

Safety ...............................................................................................................................vii

Electrical Safety .........................................................................................................vii

Pressure Safety ........................................................................................................... vii

Toxic Materials ............................................................................................................vii

Repair and Maintenance ..............................................................................................vii

Calibration .................................................................................................................. vii

Safety Conformity .......................................................................................................vii

Abbreviations .................................................................................................................... viii

Warnings .......................................................................................................................... viii

1 INTRODUCTION ................................................................................................1

1.1 Controls and Indicators ....................................................................................... 3

1.2 Function Keys ..................................................................................................... 5

1.2.1 Enter Key ..................................................................................................... 5

1.2.2 Up () and Down () Keys ........................................................................... 5

1.2.3 Right () Key ............................................................................................... 5

1.2.4 Left () / Escape Key .................................................................................... 5

1.3 Instrument Display ............................................................................................. 6

1.3.1 Display Units................................................................................................. 7

1.3.2 Status Display Indications .............................................................................. 8

2 INSTALLATION ..................................................................................................9

2.1 Safety ................................................................................................................ 9

2.2 Unpacking the Instrument ................................................................................... 9

2.3 MDM300 I.S. Accessories .................................................................................. 10

2.4 Operational Requirements ................................................................................. 12

2.4.1 Environmental Requirements – MDM300 I.S. Instrument ................................ 12

2.4.2 Charger Electrical Requirements ................................................................... 12

2.5 Instrument Gas Connections ............................................................................. 12

2.5.1 Gas Inlet /Outlet Fittings ............................................................................. 13

2.6 Connect External Sensors .................................................................................. 14

2.6.1 Set up External Sensor Interface .................................................................. 15

2.6.2 Entering User Pressure ................................................................................ 15

2.7 Battery Charging .............................................................................................. 16

3 OPERATION ....................................................................................................18

3.1 Preparation for Operation .................................................................................. 18

3.2 Instrument Start-Up ........................................................................................ 19

3.3 Overall Menu Structure and Operation................................................................ 20

3.3.1 SET-UP Menu .............................................................................................. 20

3.3.2 Chart Page ................................................................................................. 20

3.4 SET-UP Menu Parameters .................................................................................. 22

3.4.1 SETTINGS .................................................................................................. 22

3.4.2 LOGGING ................................................................................................... 23

3.4.3 BLUETOOTH ............................................................................................... 24

3.4.3.1 Bluetooth Pairing Procedure ................................................................... 25

3.4.4 EXTERNAL (Sensor Interface) ..................................................................... 26

3.4.5 CLOCK ....................................................................................................... 27

3.4.6 HMI ........................................................................................................... 28

3.4.7 INFO .......................................................................................................... 29

3.4.8 CHART Page ............................................................................................... 29

3.4.9 LOG FILES Page .......................................................................................... 30

3.4.10 LOGS Page ................................................................................................. 30

3.4.11 CALIBRATION ............................................................................................. 31

3.5 Default Parameters ........................................................................................... 32

iv 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

3.6 Guide to Measurement and Sampling ................................................................. 33

3.6.1 Measuring at Atmospheric or System Pressure .............................................. 34

3.6.2 Measurement Guide .................................................................................... 35

3.6.3 Conditional Sensor Purge ............................................................................. 37

3.7 Battery Management ........................................................................................ 37

3.7.1 Battery Troubleshooting ............................................................................... 37

4 GOOD MEASUREMENT PRACTICE .....................................................................38

4.1 Sampling Hints ................................................................................................. 39

5 APPLICATION SOFTWARE ................................................................................42

6 CALIBRATION ..................................................................................................43

6.1 Traceability ...................................................................................................... 43

6.2 Calibration Method ........................................................................................... 44

6.3 Calibration Correction Method ........................................................................... 45

7 SHIPPING .......................................................................................................46

Appendices

Appendix A Technical Speciﬁ cations .............................................................................. 48

A.1 Dimensions ................................................................................. 49

Appendix B Datalog Status Display ............................................................................... 51

Appendix C Hazardous Area Certiﬁ cation ...................................................................... 54

C.1 Product Standards ....................................................................... 54

C.2 Product Certiﬁ cation .................................................................... 54

C.3 Global Certiﬁ cates/Approvals ........................................................54

C.4 Input Terminal Parameters .......................................................... 54

C.5 Special Conditions of Use ............................................................. 55

C.6 Maintenance and Installation ........................................................ 55

Appendix D FCC Declaration .........................................................................................57

Appendix E Quality, Recycling & Warranty Information ...................................................59

Appendix F Return Document & Decontamination Declaration ........................................ 61

Michell Instruments v

MDM300 I.S. User’s Manual

Figures

Figure 1 MDM300 I.S. Advanced Dew-Point Hygrometer .............................................2

Figure 2 User Connections, Controls and Indicators ....................................................3

Figure 3 Instrument Display .....................................................................................6

Figure 4 Packing Method ..........................................................................................9

Figure 5 Gas Port Adaptors ....................................................................................10

Figure 6 Accessories .............................................................................................. 11

Figure 7 Bonded Seal Fitting ..................................................................................13

Figure 8 Gas Coupling Examples for Atmospheric Pressure Measurement ...................13

Figure 9 MDM300 I.S. Remote Sensor Interface .......................................................14

Figure 10 External Sensor Connection .......................................................................14

Figure 11 Typical External Dew-Point Display .............................................................15

Figure 12 Battery Charger Connection ......................................................................16

Figure 13 Start-Up Sequence ...................................................................................19

Figure 14 Menu Structure ........................................................................................21

Figure 15 SETTINGS Page ........................................................................................22

Figure 16 LOGGING Page .........................................................................................23

Figure 17 BLUETOOTH Page ....................................................................................24

Figure 18 Typical Bluetooth Pairing Sequence ............................................................25

Figure 19 EXTERNAL SET-UP Page ............................................................................26

Figure 20 CLOCK Page .............................................................................................27

Figure 21 HMI Page .................................................................................................28

Figure 22 INFO Page ............................................................................................... 29

Figure 23 CHART Page .............................................................................................29

Figure 24 LOG FILES Page ....................................................................................... 30

Figure 25 LOGS Page ...............................................................................................30

Figure 26 CALIBRATION Page ..................................................................................31

Figure 27 Easi-Fit Sample Kit MDM300 Panel-Mount Sampling System ......... 33

Figure 28 Large and Small Oriﬁ ce Fitting ...................................................................34

Figure 29 Typical Application Software Screen ...........................................................42

Figure 30 Typical 7-point Calibration Certiﬁ cate .........................................................43

Figure 31 Calibration Menu Page ..............................................................................45

Figure 34 Instrument Packing Details ........................................................................ 46

Figure 35 Dimensions - MDM300 I.S. ........................................................................49

Figure 36 Current Datalog File Display ......................................................................51

Figure 37 MDM300 I.S. Status Register ..................................................................... 51

Figure 38 MDM300 I.S. Status Register (Hex 28) .......................................................51

Tables

Table 1 Controls and Indicators ................................................................................4

Table 2 Instrument Display Descriptions ...................................................................6

Table 3 Adaptor Fittings ......................................................................................... 12

Table 4 SETTINGS Parameters ...............................................................................22

Table 5 LOGGING Parameters ................................................................................ 23

Table 6 BLUETOOTH Parameters ............................................................................ 24

Table 7 EXTERNAL Sensor Parameters ....................................................................26

Table 8 CLOCK Parameters .................................................................................... 27

Table 9 HMI Parameters ........................................................................................ 28

Table 10 MDM300 I.S. Default Parameters ................................................................ 32

Table 11 MDM300 I.S. Measurement Procedures ....................................................... 35

Table 12 Example Of Calibration Run Readings .......................................................... 44

Table 13 Status Register Flags ................................................................................. 52

vi 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

Safety

The manufacturer has designed this equipment to be safe when operated using the procedures detailed in this manual. The user must not use this equipment for any other purpose than that stated. Do not apply values greater than the maximum value stated.

This manual contains operating and safety instructions, which must be followed to ensure the safe operation and to maintain the equipment in a safe condition. The safety instructions are either warnings or cautions issued to protect the user and the equipment from injury or damage. Use competent personnel using good engineering practice for all procedures in this manual.

Electrical Safety

The instrument is designed to be completely safe when used with options and accessories supplied by the manufacturer for use with the instrument. The instrument is powered by an internally mounted rechargeable battery - this battery should never be allowed to fully discharge. The input power supply voltage limits for the battery charger supplied with the instrument are 100 to 240 V AC, 50/60 Hz.

NOTE: No other battery charger unit, other than that supplied with the instrument should be used.

NOTE: Do not allow the battery to fully discharge.

Pressure Safety

DO NOT permit pressures greater than the safe working pressure to be applied to the instrument. The speciﬁ ed safe working pressure (SWP), for this instrument is 350 barg (5076 psig).

Toxic Materials

The use of hazardous materials in the construction of this instrument has been minimized. During normal operation it is not possible for the user to come into contact with any hazardous substance which might be employed in the construction of the instrument. Care should, however, be exercised during maintenance and the disposal of certain parts.

Repair and Maintenance

The instrument must be maintained either by the manufacturer or an accredited service agent. Refer to www.michell.com for details of Michell Instruments’ worldwide ofﬁ ces contact information.

Calibration

The recommended calibration interval for the MDM300 I.S. is 12 months. The instrument should be returned to the manufacturer, Michell Instruments Ltd., or one of their accredited service agents for re-calibration.

Safety Conformity

This product meets the essential protection requirements of the relevant EU directives. Further details of applied standards may be found in Appendix F.

Michell Instruments vii

Abbreviations

The following abbreviations are used in this manual:

AC alternating current atm pressure unit (atmosphere) barg pressure unit (=100 kP or 0.987 atm) gauge bara bar absolute °C degrees Celsius °F degrees Fahrenheit K Kelvin (absolute temperature) COM common DC direct current ft foot (feet) Hz Hertz kg kilogram(s) lb pound Nl/min liters per minute m meter(s) mA milliampere Mb megabytes max maximum min minute(s) mm millimeter(s) MPa megapascal No. number PIN personal identification number ppm

parts per million (by volume)

ppm

parts per million (by weight)

psig pounds per square inch scfh standard cubic feet per hour SWP safe working pressure sec second(s) V volts

MDM300 I.S. User’s Manual

Warnings

The following general warning listed below is applicable to this instrument. It is repeated in the text in the appropriate locations.

Where this hazard warning symbol appears in the following

sections it is used to indicate areas where potentially

hazardous operations need to be carried out.

viii 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

1 INTRODUCTION

The MDM300 I.S. Advanced Dew-Point Hygrometer is a portable instrument designed for online measurement of moisture content in non-corrosive gases in hazardous areas, over an operational range of

The instrument is independently assessed and certificated as being intrinsically safe and fully compatible with safe operation within defined Zone 0 hazardous areas.

The instrument is contained within a steel fiber-loaded high-impact polyamide 6 case, sealed to IP66 / NEMA4 standard and is powered by an internally mounted Nickel Metal Hydride (NiMH) battery, designed to typically provide 24 hours continuous use between charges. Continuous battery charge status indication is provided. Additional battery status information is provided by a battery indicator icon, in addition to a warning beep and Shutdown Mode.

The MDM300 I.S. is fitted with an internally mounted ceramic sensor, which is enhanced for a quicker response to dew points as dry as -75°Cdp (-103°Fdp).

-100 to +20°C (-148 to +68°F).

INTRODUCTION

The MDM300 I.S. can also be used to read the dew-point signal from a Michell Instruments’ Easidew I.S. transmitter. To do this, the MDM300 I.S. Remote Sensor Interface is used to connect to the Easidew I.S. transmitter.

No other sensor can be connected to the MDM300 I.S.

A graphical display presents the dew-point data in large format characters and simultaneously provides a primary display of real time dew-point readings and a secondary display, in smaller characters, for the external sensor input. If no external input is programmed, gas temperature (measured by the internal sensor) is displayed by default.

A fully programmable, real-time, datalogging facility is provided which has an internal memory capacity of 8Mb, capable of storing up to 10,000 logs per file (typically giving a maximum of 64 log files).

A Bluetooth, wireless, communication system is provided, giving access to a dedicated, PC based, MDM300 I.S. Software Application Package which provides the facility for handling the logged data files and uploading and downloading instrument parameters.

A user-friendly operator interface provides easy access to all levels of the instrument’s functionality.

An easy-to-follow calibration routine is built into the instrument’s software.

Michell Instruments 1

INTRODUCTION

Two versions of the instrument are available, an MDM300 (standard) version and an MDM300 I.S. (intrinsically safe) version.

This manual covers the MDM300 I.S. version only.

For information about the MDM300 contact your local Michell Instruments’ representative (contact information at www.michell.com).

MDM300 I.S. User’s Manual

- I.S.

Figure 1

MDM300 I.S. Advanced Dew-Point Hygrometer

(for use in hazardous areas)

2 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

1.1 Controls and Indicators

The controls and indicators associated with the MDM300 I.S. instrument are located on the front panel of the instrument.

Connections to the MDM300 I.S. dew-point hygrometer, comprising the gas ports, battery charger input connector and input connector for the external sensor are all made to the top panel.

INTRODUCTION

Figure 2

operational functions.

shows the layout of these controls and Table 1 describes their respective

- I.S.

Figure 2

Michell Instruments 3

User Connections, Controls and Indicators

INTRODUCTION

Item Panel Description

MDM300 I.S. User’s Manual

1 Front

2 Front

3Top

4 Top Gas Output port. Refer to Section 2.5.

5 Top Gas Input port. Refer to Section 2.5.

Function keys. Refer to Section 1.2 for the details of these keys.

Instrument display, partitioned to show 3 main panels:

The primary display shows internal sensor parameters.

The secondary display indicates the external sensor parameter.

The status display area shows icons representing battery charge state, initialization in progress, data logging in progress, keyboard lock status and keyboard beep status.

Instrument ON/OFF switch.

NOTE: The instrument does not need be switched ON in order to charge the internal NiMH battery.

Analog input connector for external sensor.

By default, this signal is displayed in the secondary display area but may be conﬁ gured to be displayed as the primary display.

6Top

7 Top

If no external input is selected, the internal sensor temperature is shown, on the secondary display, by default (refer to Section 3.4.6).

NOTE: The hinged rubber protection cover should be kept closed when the connector is not in use.

Socket for connection of battery charger secured cover).

The secured cover should be kept screwed on when the connector is not in use.

(located behind

Connection to the battery charger should always be made in a safe area - never in a hazardous area environment

ONLY USE THE CHARGER PROVIDED

Table 1 Controls and Indicators

Never allow the battery to fully discharge

4 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

1.2 Function Keys

The function keys, located on the front panel, are used to select operations from the menus and to select and enter parameter variables within those menu levels.

The function key described is shaded darker and the operation of the keys is as follows:

1.2.1 Enter Key

The Enter key is used within the menus to highlight and select options and to accept entered values.

Operation of this key from the Main Display causes the Passcode entry page (for entry to the SET-UP Menu) to be displayed.

1.2.2 Up () and Down () Keys

Within the SET-UP Menu and sub-menus these  and  keys are used to scroll down and highlight options.

INTRODUCTION

Within sub-menu levels requiring the entry of alpha numeric values, these keys are used to change the values. Pressing the key once increases or decreases the selected field by one step. Pressing and holding the key will cause the selected field to be continuously increased or decreased until the key is released.

1.2.3 Right () Key

Within sub-menu levels requiring the entry of alpha numeric values, this  key is used to shift the insertion point right in the file name entry field.

From the Main Display, pressing this  key moves to the Chart Page.

From the Chart Page, pressing this  key moves to the Logging Pages.

1.2.4 Left () / Escape Key

Within sub-menu levels requiring the entry of alpha numeric values, this  key is used to shift the insertion point left in the file name entry field. As the insertion point is shifted to the left, the entry at the former position is deleted.

Within any menu or sub-menu level, pressing this  key escapes to the previous menu above the current level.

Michell Instruments 5

INTRODUCTION

1.3 Instrument Display

MDM300 I.S. User’s Manual

The graphics display and the associated function keypad ( interface of the equipment. after the instrument’s initialization period has completed.

Table 2 details the elements of the display:

Figure 3

shows all the elements of a typical display page

Dewpoint Internal

°C

6.9

12.7

°C Temp.

Measurement in progress

Figure 3

Item Description

Secondary display

Shows reading from external sensor, if conﬁ gured; or internal temperature if external sensor is not conﬁ gured (refer to Section 3.4.6).

Battery charge indicator icon

Flashes when the battery needs charging. A warning beep sounds when the

battery charge level is critical - followed immediately by Shutdown Mode.

NOTE: The icon becomes animated when the charger is connected. Keyboard beep indicator

Indicates that the keyboard beep is switched on.

Keyboard lock indicator

Indicates that the keyboard is locked.

Datalog status indicator

Indicates that logging is enabled and running.

Sensor initializing indicator

Indicates that the initialization process is in progress and that the sensor heating

is on. The presence of this symbol is accompanied by status message.

Primary display

During normal operation, the internal sensor readings are shown in the

primary display. If the external sensor has been conﬁ gured then this reading can be shown in this display (refer to Section 3.4.6).

8 Status message display area

Displays status and error messages.

Instrument Display

Figure 2),

form the operator

12346785

Initializing internal sensor

Table 2 Instrument Display Descriptions

6 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

1.3.1 Display Units

The instrument can display the measured reading in the following units:

Absolute Humidity

INTRODUCTION

• lb/MMscf

• g/m

• g/m3 NG

Moisture Content

• ppmV NG

• ppmV

• ppmW (AIR, USER, H

Dew Point

• °C

• °F

• K

Relative Humidity (%)

Mixing Ratio

• g/kg (AIR, USER, H

, SF6, CO2 or N2)

To toggle between displayed units, press either the  or  key.

Michell Instruments 7

INTRODUCTION

1.3.2 Status Display Indications

‘Initializing Internal Sensor’

This is displayed immediately after the instrument has been powered up, and indicates that the sensor is being heated up to accelerate equilibrium with the moisture in the sample gas. This has the effect of drying the sensor out, and results in the ‘undershoot’ seen in the first stage of the measurement process.

‘Measurement in Progress’

This is displayed after the sensor initialization has finished, and indicates that the sensor is running through the following initial measurement procedure:

1. Undershooting the dew-point

2. Making a first estimate

3. Running a QRA (Quick Response Algorithm), if necessary

MDM300 I.S. User’s Manual

Once the message has disappeared, this indicates that the instrument has finished its accelerated approach to the actual dew point. Depending on the conditions, it may continue to respond for a number of minutes more, before settling on (or tracking) the actual measured dew point.

Other Status Display Indications

Internal sensor error

Internal thermistor error

External sensor error

Battery low Battery low -

recharge now

Log  nished

Internal sensor not found

Default CONFIG  le used

Dew-point reading out of range (> +30 / < -120°C)

Sensor internal temperature reading out of range (> +100 / < -40°C) or Thermistor fault

External Sensor Input out of range (< 4 mA / > 20 mA)

Battery level low - recharge as soon as possible

Battery level critical - recharge immediately

Log ﬁ le has reached the maximum of 10,000 logs and logging has been stopped

Could not detect internal sensor on power up

Conﬁ g. ﬁ le missing, new ﬁ le created and default settings used

8 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

MDM300 I.S.

Advanced Dew-Point Hygrometer

User’s Manual

- I.S.

97213 Issue 4 September 2012

2 INSTALLATION

2.1 Safety

It is essential that the installation of the electrical and

gas supplies to this instrument be undertaken by qualiﬁ ed

2.2 Unpacking the Instrument

The MDM300 I.S. instrument is packed into a standard box and the method of unpacking is shown below:

INSTALLATION

personnel.

00000 Issue 1 October 08

00000 Issue 1

October 08

- I.S .

Figure 4

Packing Method

1. Open the box (1) and unpack carefully.

2. Remove the MDM300 I.S. (2), the user’s manual (3) and the accessories box (4).

3. Save all the packing materials for the purpose of returning the instrument for re-calibration or any warranty claims.

4. If the optional carry bag has been ordered it will be located underneath the foam insert, in a cardboard box.

Michell Instruments 9

INSTALLATION

2.3 MDM300 I.S. Accessories

MDM300 I.S. User’s Manual

The accessories for the MDM300 I.S. are shown in as standard and item 8 is optional. Please check that all the standard components are present after unpacking. Report any shortages immediately.

1. Calibration certificate

2. User’s manual

3. Charger unit

4. Country specific mains lead

5. Gas Input/Output port adaptors

(three provided - two fitted to the instrument - see

6. Application Software CD

7. Quick-start card

8. Carrying case - made from anti-static materials suitable for use in hazardous areas (optional)

Three gas port adaptors are provided, two with a large bore orifice and one with a small bore orifice. Depending upon configuration, this permits the instrument to be run at either system pressure or atmospheric pressure and facilitates the connection of external flow monitoring and control.

Figure 6

Figure 5

. Items 1 to 7 are supplied

)

NOTE: On delivery the two large orifice adaptors are fitted into the instrument’s gas ports (1 and 2) as shown in as a loose spare in the accessory pack (see Section 2.5).

Figure 5

- I.S.

. One small orifice adaptor is provided

Small orice

Large orice

Gas In Gas Out

Figure 5

Gas Port Adaptors

10 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

MDM300 & MDM300 I.S. Quick Start Guide

97244 Issue 02, July 2011

Atmospheric

System

Yes

Connect the MDM to the sample gas stream

Determine the approximate

dew point by using the ‘initial check’

procedure on the reverse

The instrument will begin Measurement mode. During the first few minutes of this, the displayed moisture value will drop rapidly below the actual

moisture value, before returning

to a stable reading.

The instrument’s display will show an initial

measured value, and the status display will show ‘Measurement in progress’.

Do you want to measure at Atmospheric pressure or System pressure?

After the initialization period is complete, close the outlet flow control valve and fully open the inlet flow control valve . Then adjust the flow rate using the outlet flow control valve to between 0.2 and

0.5 l/min.

Is the

equivalent dew point > - 40Cdp?

Turn the instrument

on. The status display

will read ‘Initializing

internal sensor’

Turn the instrument on. The status display

will read ‘Initializing

internal sensor’

Turn the instrument on.

The status display will read

‘Initializing internal sensor’.

Adjust the flow rate

using the

inlet flow control valve

between

0.2 and 0.5 l/min

Adjust the flow rate

using the

inlet flow control valve

between

0.2 and 0.5 l/min

Adjust the flow rate

using the

outlet flow control

valve to between

0.2 and 0.5 l/min

Typical MDM300 Sampling Arrangement

VENT

SAMPLE FLOW

Coalescing Filter Particulate Filter Inlet Flow Control Valve Outlet Flow Control Valve

Once ‘Measurement in progress’

has disappeared, the instrument is close

to the final dew point. Depending on the conditions, it may continue to respond for a number of

minutes before tracking the measured dew point.

HIGH PRESSURE! High pressure gases are potentially hazardous. Energy stored in these

JDVHVFDQEHUHOHDVHGVXGGHQO\DQGZLWKH[WUHPHIRUFH+LJKSUHVVXUHV\VWHPVVKRXOGEH DVVHPEOHGDQGRSHUDWHGRQO\E\SHRSOHZKRKDYHEHHQWUDLQHGLQSURSHUVDIHW\SUDFWLFHV

MDM300 I.S.

Advanced Dew-Point Hygrometer

User’s Manual

- I.S.

97213 Issue 4.1

June 2013

INSTALLATION

Figure 6

Accessories

Michell Instruments 11

INSTALLATION

MDM300 I.S. User’s Manual

2.4 Operational Requirements

Operational requirements are as follows:

Sample gas flow rate: 0.2 to 0.5 Nl/min (0.5 to 1 scfh) Operating pressure: 0 to 350 barg (0 to 5076 psig)

2.4.1 Environmental Requirements – MDM300 I.S. Instrument

Operating temperature range: -20 to +50°C (-4 to +122°F)

Humidity: 0 to 100% RH (non-condensing)

Altitude: Up to 2000m (6562 ft)

2.4.2 Charger Electrical Requirements

Charger supply voltage: 100 to 240 V AC (+10%, -15%) 50/60 Hz (±5%), 8 VA

2.5 Instrument Gas Connections

POSSIBLE INJURY! The tubing, valves and other apparatus

attached to this instrument must be adequate for the

maximum pressure which will be applied, otherwise physical

injury to the operator or bystander is possible.

Sample gas connections are made via the Gas In (2) and Gas Out (1) ports located on the rear of the instrument as shown in

The MDM300 I.S. is supplied with a large bore orifice fitting installed into the Gas In and Gas Out ports. These fittings have an 1/8” NPT female thread to allow the user to connect other components of their choice.

Atmospheric pressure or system pressure dew point can be measured depending on the configuration of the adaptor fittings as shown in Table 3.

For gas pressures outside the range 2.5 to 10 barg, the instrument requires external flow control components, as shown in

Dew point at

Atmospheric Small bore oriﬁ ce Large bore oriﬁ ce

System Large bore oriﬁ ce Small bore oriﬁ ce

Either (using

other ﬂ ow control

components)

Gas Inlet port

ﬁ tting

Large bore oriﬁ ce Large bore oriﬁ ce

Figure 5

Figure 8.

Gas Outlet port

ﬁ tting

Sample gas

pressure

2.5 to 10 barg

(36 to 145 psig)

2.5 to 10 barg

(36 to 145 psig)

0 to 350 barg

(0 to 5076 psig)

Table 3 Adaptor Fittings

12 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

2.5.1 Gas Inlet /Outlet Fittings

HIGH PRESSURE! High pressure gases are potentially

hazardous. Energy stored in these gases can be released

suddenly and with extreme force. High pressure systems

should be assembled and operated only by people who have

Before making a measurement, the gas fittings should be attached to the instrument as shown in Table 3

1. Fit the required orifice fittings with supplied bonded seals. Ensure bonded seals are correctly seated in recessed grooves.

INSTALLATION

been trained in proper safety practices.

PTFE tape here

Adaptor

Figure 7

I.S

Bonded seal

Bonded Seal Fitting

)

1/8” Swagelok

tting

2. Fit any other adaptors that might be required.

3. If the small bore orifice fitting is not being utilized then one of the optional application kits could be fitted (as shown below

Figure 8

NOTE: The application kit shown above (excluding the orifice fittings) is not supplied as standard, but is part of a range of kits which can be ordered from Michell Instruments, on request.

NOTE: The bonded seals used for the MDM300 I.S. are Dowty part number 400-228-4490-74 (from Michell Instruments, part number MDM300-DS).

Gas Coupling Examples for Atmospheric Pressure Measurement

Michell Instruments 13

INSTALLATION

2.6 Connect External Sensors

The MDM300 I.S. can be configured for connection to a Michell Instruments’ Easidew I.S. transmitter (ATEX Baseefa 06ATEX0330X, IECEx BAS06.0090X), via the MDM300 I.S. Remote Sensor Interface, when the Easidew I.S. transmitter is installed within a hazardous area.

The MDM300 I.S. Remote Sensor Interface is a passive device. The combined terminal parameters of the MDM300 I.S. and of the barrier used with the Easidew I.S. system must not exceed the input terminal parameters of the Easidew I.S. as specified in the System Drawing (System Certificate No. Baseefa 07Y0027).

To view any of these certificates go to: http://www.michell.com

MDM300 I.S.

Connect to



MDM300 I.S. User’s Manual



Connect to

EASIDEW I.S. SYSTEM

Figure 9

MDM300 I.S. Remote Sensor Interface

Refer to Appendix C (Hazardous Area Certification) for the MDM300 I.S. terminal parameters.

Figure 10

shows the connection of the MDM300 I.S. Remote Sensor Interface to the

MDM300 I.S. and the Easidew I.S. transmitter.

HAZARDOUS AREA SAFE AREA

REMOTE SENSOR INTERFACE

- I.S.

MDM300 I.S.

Connect to

S . I

C A F

Connect to

e S .

S .

sid

EASIDEW I.S. SYSTEM

20mA 0Hz 28Vdc Li = 0

Ci = 37nF

Pi = 651m

Ii = 93mA

Ui = 28V

Entity Ex90385 Terminal

Safe Ex ia Class 1, Division 1, Group A,B,

E416-051

Ex ia IIC T4 -20C to +60C IECEx BAS 06.0090X Baseefa06ATEX0330X

EASIDEW I.S. Dew Point Tran

www.michell.com

,5 Nm Ely, Cambs UK

EASIDEW I.S.

EASIDEW I.S. SENSOR BARRIER ASSEMBLY

SYSTEM CERT Baseefa 07Y0027

MDM300 I.S.

Figure 10

External Sensor Connection

14 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

2.6.1 Set up External Sensor Interface

After connecting the Easidew I.S. transmitter, the following parameters must be defined:

INSTALLATION

Switch on the instrument and set the required the SETTINGS Menu (refer to Section 3.4.1). Set up the required pressure units.

Using the external Easidew input as follows (refer to Section 3.4.4):

EXTERNAL option from the SET-UP Menu, set up the instrument for an

DP/TEMP units to either °C, °F or K from

EXTERNAL TYPE Select EASIDEW

EXTERNAL ZERO

-100°C (DP Temp represented by 4 mA input - can be reset)

EXTERNAL SPAN 20°C (DP Temp represented by 20 mA input - can be reset)

USER PRESSURE Refer to Section 2.6.2. NOTE: Pressure compensation does not

affect the reading of the external sensor.

After completion of the above settings, return to the Main Display. The instrument will now display dew point from the external sensor in the secondary display area and the selected units. (Refer to Section 3.4.6 for more information.)

An example is shown below

Figure 11

2.6.2 Entering User Pressure

The MDM300 I.S. can be programmed with a pressure to be used in the calculation of atmospheric equivalent or pressure dew point, moisture content or absolute humidity.

NOTE: Care should be taken to ensure that the entered pressure is correct as it may have a considerable effect on the measurement.

Using the

1. Scroll to

2. Use the  and  keys to select either

EXTERNAL option in the SET-UP Menu, set a user pressure as follows.

USER PRESSURE.

the required pressure.

Dewpoint External

-26.9

°C

Typical External Dew-Point Display

-25.7

°C dp

ATM (for atmospheric pressure) or

NOTE: The pressure units are selected in the Settings Menu.

Michell Instruments 15

INSTALLATION

2.7 Battery Charging

WARNING: The battery charger must NOT be connected within

The MDM300 I.S. is powered from an internally mounted, rechargeable Nickel Metal Hydride (NiMH) battery. Typically, depending upon the instrument settings, the battery will provide approximately 24 hours of continuous operation when fully charged.

A graphical display of battery charge state is provided and an audible warning is given as the battery approaches full discharge.

Loosen the securing screw and swing aside the sealing cover (2). Insert the battery charger connector (1) into the charger connector as shown in

MDM300 I.S. User’s Manual

the hazardous area.

The battery charger socket cover MUST be closed when the

product is in use within a hazardous area.

Figure 12.

- I.S.

Figure 12

Connect an AC power supply, 100 to 240 V AC, 50/60 Hz, to the battery charger unit.

Battery Charger Connection

NOTE: The MDM300 I.S. instrument does not need to be switched on in order to charge the battery.

16 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

The battery charger supplied is a ‘Smart’ charger.

WARNING: DO NOT use any other charger than that supplied

The use of any charger other than that supplied for use will

The smart charger goes through three charging stages:

• pre-charge

• fast-charge

• trickle charge

INSTALLATION

with this product.

invalidate the product warranty.

If the battery has been damaged then the charger will not begin the fast-charge stage. Please contact Michell Instruments’ service department for advice.

Once the charger has finished the fast-charge stage it can be safely disconnected. Switch off the AC power supply, remove the charger unit and close the instrument’s charge connector protection cover.

A complete charge cycle will take 2 to 4 hours for a fully discharged battery.

The table below shows the different charging stages and durations.

Stage / Charger

Pre-charge Flashes Orange Orange Up to 5 minutes

Rapid-charge Flashes Green (Fast) Red 2 to 4 hours

Trickle-charge Flashes Green (Slow)

Charging complete

FW 7219 Type

(Older)

Green Green N/A

Cell-con

(Newer)

Green, ﬂ ashes

Orange

Duration

Indeﬁ nite - Cell-con

One hour - FW

FW 7219

Cell-con

Michell Instruments 17

OPERATION

3 OPERATION

High pressure gases are potentially dangerous.

POSSIBLE INJURY! The tubing, valves and other apparatus

attached to this instrument must be adequate for the

maximum pressure which will be applied, otherwise physical

injury to the operator or bystander is possible.

3.1 Preparation for Operation

MDM300 I.S. User’s Manual

The MDM300 I.S. has a user-friendly system of operation. Before operation it is recommended that the user becomes familiar with Section 1 of this manual in which the equipment controls and indicators, and the elements of the display are described.

Prior to making a measurement, the instrument must have been connected to a sample gas stream, see Section 2.5.

It is recommended that the battery is charged before conducting any tests (refer to Section 3.7).

The instrument will have been set up with a number of factory default parameters. These default parameters are shown in Table 10, together with a reference to the relevant part of this manual which details the method of changing these default values.

18 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

3.2 Instrument Start-Up

At switch on, the instrument goes through an initialization process of between 4 and 7 minutes, depending on the sensor and sample gas characteristics. During this time the internal sensor is heated to a maximum of +60°C (+140°F). The heating process increases the mobility of water molecules and accelerates equilibrium with the passing sample gas

During this period the sample gas flow purges the system. After this period, the sensor will be dried to below the dew point of the gas to be measured. The heating is then switched off and the display becomes dynamic.

Figure 13

shows a typical start-up sequence.

OPERATION

MDM300 I.S.

System Initializing

Initializing: 04:32

Initializing internal sensor

Dewpoint

ppmv

19.216

10.3

Measurement in progress

°C

Internal

60.0

°C Temp.

Internal

22.3

°C Temp.

At switch-on, the System Initializing Page is displayed for several minutes during which the page will show a

countdown of the remaining initialization time. NOTE:

Dewpoint

9.1

°C

Internal

22.3

°C Temp.

The initialization stage is skipped if the initial dew point is detected to be within 2°C of the dew point when the instrument was switched

Figure 13

Start-Up Sequence

off.

During this period, gas will be flowing through the sensor and can be externally regulated to meet the instrument’s flow requirements, and the real time sensor temperature is indicated in the secondary display area. The initializing icon (item 6 in

Figure 3)

is displayed in the status area and the keyboard is locked out until the initialization period has expired.

It is possible to terminate the initialization process before the initialization period has timed out by pressing the  and  keys simultaneously. This action aborts the instrument’s response enhancement system and allows the operator to make an immediate measurement if the measured dew point is wetter than -20°Cdp (-4°Fdp).

While the initialization process is in progress, the backlight time-out is inhibited and, if any external sensor has been configured and connected to the instrument, display of the external sensor reading is also inhibited.

After the end of the initialization period, the display reverts to Measurement Mode displaying dew point (in the currently selected unit) in the primary display area, and any external sensor reading in the secondary display area. By default, the internal temperature is displayed in the secondary display area if no external sensor is configured.

If an external sensor has been selected but has either not been connected or is giving an over-range indication, a flashing

External Sensor Error message (alternating with a

Measurement in progress message) will be displayed.

While the Quick Response Algorithm is in operation a message is displayed. After this, depending on the sample conditions, the instrument may continue to respond to the final dew-point for a number of minutes. This is further explained in Section 3.6.

Measurement in progress

Michell Instruments 19

OPERATION

3.3 Overall Menu Structure and Operation

3.3.1 SET-UP Menu

All instrument settings are made from the SET-UP Menu which is accessible from the Main Display by pressing the

On the first occasion after switch-on the Passcode Entry page will be displayed. Enter the passcode

7316 as follows:

Enter key.

MDM300 I.S. User’s Manual

• With the first digit of the passcode highlighted, enter the first digit ( using the  and  keys.

• Press the position.

• Repeat this procedure until all the passcode digits have been entered. On successful entry of the last digit, the SET-UP Menu will be displayed.

NOTE: If the passcode is incorrectly entered, the passcode page remains displayed

showing the entries that have been made. To accept any digit as correct and to move to the next digit position, press the

or  keys, and when the correct passcode has been entered, the SET-UP Menu will be displayed.

Within this SET-UP Menu, eight options are available:

Enter key to accept this entry and move to the next digit

Enter key. Change the incorrect entry, using the

SETTINGS, LOGGING, BLUETOOTH,



EXTERNAL, CLOCK, HMI, CALIBRATION and INFO. For more detailed information on

these options refer to Section 3.4.

These options are selected by means of the  and  keys. Pressing the provides access to a sub-menu which permits the variables associated with that option to be edited, as follows:

Enter key then

• Press the  and  keys to highlight the required field.

• Press the

• Press the  and  keys to edit the parameter value associated with that field.

• Press the

Quit the sub-menu by pressing the  key and return to the SET-UP Menu. From the SET-UP Menu either select another sub-menu with the  key or press the  key to return to the Main Display.

3.3.2 Chart Page

The Chart Page is reached from the Main Display, by pressing the  key. The chart interval is set up under the SETTINGS Menu. For more information on the Chart Page refer to Section 3.4.8.

Pressing the  key when the chart is displayed will show either the Log Files (if Logging

is not selected), or the current data Logs Page (if Logging is selected). If Logging is

not selected press the

Where more than one page of data is available, the  and  keys are used to scroll up or down.

Enter key to select the field.

Enter key to enter the new value.

Enter key for a shortcut to the LOGGING Menu.

20 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

OPERATION

Main Display (Primary, Secondary and Status

PASSCODE FOR

SETUP (on start-up

only)

=7316

PASSCODE

SET-UP

SETTINGS LOGGING

BLUETOOTH

EXTERNAL

CALIBRATION

Scroll menu items

Scroll Unit

to view

Windows)

Scroll to

Adjust Digit

CLOCK

HMI

INFO

To select

item

Chart Page

(only if internal sensor

available)

Chart Reset Page

Scroll to

adjust digit

PASSCODE FOR CAL

=4876

PASSCODE

OK?

YES

LOGGING?

YES

Scroll

menu items

and edit

Files Page

Logs Page

To return to

previous screen

PRIMARY DP AT

DP/TEMP UNIT

PRESSURE UNIT

GAS TYPE

MOL WEIGHT

CHART INTERVAL

FILE NAME

PARAMETER

LOG INTERVAL

START?

ENABLE

NAME

EXTERNAL TYPE EXTERNAL ZERO

EXTERNAL SPAN USER PRESSURE

YEAR

MONTH

DAY

HOUR

MIN

CONTRAST

BRIGHTNESS

KEY TONE

BL TIMEOUT

LANGUAGE

PRIMARY DISP

To toggle

selection of

item

Figure 14

LEGEND

Enter Key

Left Right Keys

Menu Structure

POINT

REF

MDM300

INFO PAGE

Up/Down Keys

Michell Instruments 21

OPERATION

3.4 SET-UP Menu Parameters

Follow the instructions in Section 3.3.1 to select the required parameters.

3.4.1 SETTINGS

MDM300 I.S. User’s Manual

PRIMARY DP AT ATMOS

DP/TEMP UNIT °C PRESSURE UNIT Psig GAS TYPE AIR MOL WEIGHT N/A CHART INTERVAL 5 s

Parameter Description

Indicates if the primary display sensor is at atmospheric or system

PRIMARY DP AT

pressure. Available Input:

DP/TEMP UNIT

PRESSURE UNIT

Sets system temperature units. Available Input:

Sets system pressure units. Available Input:

Deﬁ nes the sample gas type.

NOTE: The

GAS TYPE

gases other than For any other type of sample gas, the molecular weight of the gas

must be deﬁ ned in the Available Input:

MOL WEIGHT

CHART INTERVAL

Sets molecular weight of user-deﬁ ned sample gas, default value 1. Available Input: Range

Sets chart time interval, default value 5. Available Input: Range

Figure 15

ATMOS or PRESS (Atmospheric or Pressure)

°C, K, °F

psig, MPa, psia, bara, KPa, barg,

MOL WEIGHT ﬁ eld automatically reads N/A for all

Air, USER, H2, SF6, CO2, N2

SETTINGS

SETTINGS Page

USER.

MOL WEIGHT ﬁ eld.

1 to 99

1 to 60 seconds

Table 4 SETTINGS Parameters

22 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

3.4.2 LOGGING

Logging can be set up either from the SETTINGS Menu or from the Chart Page (see Section 3.4.8). Both methods of entry lead to the same LOGGING SET-UP menu as shown below:

OPERATION

Parameter Description

Deﬁ nes datalog ﬁ le name. Field width up to eight alphanumeric characters.

NOTE:  key deletes characters

FILE NAME

NOTE: If a ﬁ le name is not entered, a logging cycle cannot be started.

Available Input: numbers to letters or vice-versa)

Sets parameter to be logged. This need not necessarily be the same as that displayed on the Main Display.

PARAMETER

NOTE: Only one parameter may be logged at one time

Available Input:

GM3(NG), LBMMSCF, PPMV(NG)

LOG INTERVAL

START ?

Sets log interval in 5 sec increments. Available Input: Range

Starts the log cycle after logging parameters are set-up.

NOTE: If a ﬁ le name is not entered, a logging cycle cannot be started.

Once logging has started, log ﬁ le parameter ﬁ elds are locked out and cannot be changed.

Available Input:

FILE NAME

PARAMETER LOG INTERVAL START?

Figure 16

DEWP 5 STOPPED

LOGGING

LOGGING Page

0 - 9, A - Z (keying up and down will change the

DEWP, GM3, GKG, RH, PPMW, PPMV, CALC DP,

5 to 600 seconds

STOPPED, STARTED

Table 5 LOGGING Parameters

NOTE: If a duplicate file name has been entered an error message will be shown when attempting to start logging.

A maximum of 64 log files can be stored in the instrument memory before it is necessary to download or remove them. The

START ? option will not be

available if this limit is exceeded.

Cycling power will stop the logging.

The size of any one log file is limited to 60kb. If the unit is left logging, and the file size exceeds 60kb, then the log file will finish automatically. To ensure that the log file you initiate collects all the data from your test, an

Michell Instruments 23

OPERATION

appropriate sample time should be chosen. The table below can be used as a rough guide:

3.4.3 BLUETOOTH

Bluetooth mode is used, in conjunction with a dedicated MDM300 I.S. application software package, for the purpose of uploading datalog files to a PC using a wireless connection. Within the PC the dedicated Michell application software package is used to upload the files to the PC’s desktop, from where they can be loaded into other programs, e.g. Microsoft Excel, for further examination and processing.

MDM300 I.S. User’s Manual

Sample time (sec) Logging duration

5 3 hours 10 6 hours 30 18 hours 60 36 hours

100 60 hours 200 120 hours 400 240 hours 600 360 hours

ENABLE NO

NAME MDM300

Figure 17

Parameter Description

Turns the Bluetooth facility on or off.

When Bluetooth is turned ON - a status message *in

ENABLE

Bluetooth mode* will be displayed. No other menu options

can be selected at this time and this page remains until the Bluetooth mode is cancelled by pressing the  key.

Available Input:

Before enabling Bluetooth (above) set up a Bluetooth name (address)

for the instrument. Maximum eight alphanumeric characters. Default

NAME

name set is MDM300. Available Input: 0 - 9, A - Z (keying up and down will change the

numbers to letters or vice-versa)

BLUETOOTH

BLUETOOTH Page

ON or OFF

Table 6 BLUETOOTH Parameters

24 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

3.4.3.1 Bluetooth Pairing Procedure

When the instrument is in Bluetooth mode, a pairing procedure needs to be carried out in order for the PC system to recognize the instrument. This procedure only needs to be carried out once for each instrument. A typical pairing procedure is outlined in procedure is as follows:

1. From the PC’s Bluetooth menu, search for devices in range. This yields the instrument named, i.e. MDM300.

2. Double click the instrument icon and enter the instrument’s pairing passcode (

will be shown only briefly as it is entered and then hidden.

7316) for all MDM300 I.S. instruments. NOTE: Each digit

OPERATION

Figure 18.

The

3. When all digits have been entered click

4. With the serial link established, click

the COM port allocated, i.e. COM7, will need to be entered when starting the Michell application software.

(6)

(1)

(3)

(7)

Next.

Configure. NOTE: The name of

Figure 18

Typical Bluetooth Pairing Sequence

Michell Instruments 25

OPERATION

3.4.4 EXTERNAL (Sensor Interface)

The MDM300 I.S. is designed to be connected ONLY to a

Michell Instruments’ remotely mounted Easidew I.S. or

Easidew PRO I.S. transmitter. Connection to any other type of

The Easidew I.S. or Easidew PRO I.S. must be connected retaining the associated I.S. barriers and using a Michell

Remote Sensor Interface module. See Section 2.6.

MDM300 I.S. User’s Manual

sensor could impair safety.

Figure 19

Parameter Description

Deﬁ nes use of Easidew I.S. transmitter.

EXTERNAL TYPE

EXTERNAL ZERO

EXTERNAL SPAN

USER PRESSURE

NOTE: The ZERO and SPAN limits are automatically added for this transmitter.

Available Input: Deﬁ nes external zero (lower limit).

ZERO default limit is pre-programmed but can be redeﬁ ned.

The Available Input: Range:

Deﬁ nes external span (upper limit).

SPAN default limit is pre-programmed but can be redeﬁ ned.

The Available Input: Range:

Used in the calculation of dew point at pressure, moisture content and absolute humidity. If a user pressure is not selected then the MDM300 I.S. assumes atmospheric pressure. (Refer to Section 2.6.2.)

NOTE: Pressure compensation does not affect the reading of the external sensor.

Available Input: Range units).

EXTERNAL TYPE NONE

EXTERNAL ZERO N/A EXTERNAL SPAN N/A USER PRESSURE ATM Psig

EXTERNAL SET-UP Page

NONE, EASIDEW

-120 to +30°C

AT M, 0 to 300 barg (or equivalent in other

EXTERNAL

Table 7 EXTERNAL Sensor Parameters

26 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

3.4.5 CLOCK

YEAR 11 CLOCK

MONTH 03 DAY 26 HOUR 09 MIN 32

OPERATION

Parameter Description

YEAR

MONTH

DAY

HOUR

MIN

Current year

Available Input: Range: 00 to 99

Current month

Available Input: Range: 01 to 12

Current day

Available Input: Range: 01 to 31

Current hour

Available Input: Range: 00 to 23

Current minute

Available Input: Range: 00 to 59

Figure 20

CLOCK Page

Table 8 CLOCK Parameters

Michell Instruments 27

OPERATION

3.4.6 HMI

MDM300 I.S. User’s Manual

CONTRAST 80 %

BRIGHTNESS 75 % KEY TONE ON BL TIMEOUT 30 s LANGUAGE ENG PRIMARY DISP INTERN

Parameter Description

CONTRAST

BRIGHTNESS

KEY TONE

BL TIME-OUT

LANGUAGE

Sets the contrast on the screen. Available Input: Range:

Sets the brightness of the screen. Available Input: Range:

Turns the key tone on or off. Available Input:

Backlight control. Available Input:

Sets the language required. Available Input:

Sets the display option.

PRIMARY DISP

NOTE: This option is only accessible if an external sensor has been conﬁ gured - see below.

Available Input:

HMI

Figure 21

HMI Page

0 to 100% in 5% increments

ON, OFF

OFF, 15 to 60 sec in 15 sec increments

ENG, DEU, ESP, FRA, ITA, POR

INTERN, EXTERN

Table 9 HMI Parameters

If no external input is selected, the internal sensor temperature is shown, on the secondary display, by default.

When an Easidew I.S. transmitter has been configured, the primary and secondary displays can be interchanged to show the external sensor reading as the main display and the internal sensor reading as the secondary display.

With an Easidew I.S. transmitter connected, the ability to display the output of the external device as the main (large character) display can be particularly advantageous for a number of applications such as:

• Remote monitoring

• Calibration checks on an existing installation

• High pressure measurements

28 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

3.4.7 INFO

MDM300 I.S. Portable Hygrometer

Firmware 36176 Ver 0.01 Sensor serial number E050-035 Sensor next cal due 03/09/12 Sensor hours used

www.michell.com

20 hr

OPERATION

This page contains system information and no changes can be made.

Information available:

• Firmware number and version

• Sensor serial number

• Date of sensor calibration next due

• Hours that the sensor has been used

3.4.8 CHART Page

At any time while the Main Display is indicating internal sensor parameters, a graphical display of the output can be obtained by pressing the  key from the Main Display.

Figure 22

INFO Page

The chart can be reset at any time by pressing the

Enter key. Reset the chart by

pressing the  key or return to the chart, without resetting, by pressing the  key.

A typical chart plot is shown below:

t-5

Figure 23

CHART Page

Val 55.6 Min 55.3 Max 68.7

%RH

tMinutes

The X-axis (time) has a default range of 5 minutes and the graph is incremented (drawn) at the interval set up under the SETTINGS Menu (see Section 3.4.1). The Y-axis shows the measured value, with respect to time.

The current, maximum and minimum values of the displayed parameter are shown to the right of the graph and the unit of the selected parameter is displayed below.

Michell Instruments 29

OPERATION

3.4.9 LOG FILES Page

If the instrument is not logging, pressing the  key, while the chart is displayed, will

show the FILES Page. This page provides a list of all the previously saved log files, together with an indication of the available memory capacity (see through the list, use the  and  keys as required.

MDM300 I.S. User’s Manual

11 les

1.txt 1K 0130 1318

2.txt 1K 0130 1319

3.txt 15K 0305 1352

4.txt 4K 0315 1738

Not logging, press ENTER to setup logging



169K used 8397K Free



Figure 24)

. To scroll

The content of the datalog files cannot be examined but, by enabling the instrument’s Bluetooth mode, (see Section 3.4.3), the MDM300 I.S. application software may be used to upload the datalog files to a PC.

In the FILES Page a shortcut to the LOGGING Set-Up Menu is provided by pressing the

Enter key. Refer to Section 3.4.2 for logging set-up details.

3.4.10 LOGS Page

If the instrument is logging, pressing the  key, while the chart is displayed, will show

the LOGS Page. The page shows the current log file.

In the LOGS Page a shortcut to the LOGGING Set-Up Menu is provided by pressing the

Enter key. Refer to Section 3.4.2 for logging set-up details.

The  and  keys are both active while the log file is being displayed. To view log points taken earlier in the logging cycle, press the  key. To continuously scroll back, keep the  key pressed down.

Figure 24

LOG FILES Page

Similarly, to move forward in the list press the  key, once for a single step, or press and hold to continuously scroll forward.

106 107 108 109 110

INT

26.8

26.2

25.9

25.8

25.5

EXT

-100.0

-90.0

-80.0

-70.0

-60.0

Figure 25

0028 0028 0028 0028 0028

File CR030911 INT RH EXT. EXT_DP INTVAL 05 Sec D# 110903 T# 123606

LOGS Page

30 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

The display shows:

OPERATION

INT

EXT

Indicates a log number for each set of log points

Value of primary display parameter

Value of secondary display parameter Status column which reports the status of the instrument at each log

point in hexadecimal code. The status codes are explained in Appendix B.

•

FILE File name

INT Primary display parameter being logged

EXT Secondary display parameter being logged

INTVAL Logging interval

D# Current date in YYMMDD format

T# Current time in HHMMSS format

NOTE: The chart and datalogging are independent functions; therefore the parameter displayed on the chart may not necessarily reflect what is being logged.

3.4.11 CALIBRATION

Entry to the CALIBRATION Menu is protected by a passcode (4876). The passcode is entered in a similar manner to that described in Section 3.3.1.

This page gives access to the internal sensor’s calibration look-up table and provides the facility to select and change any single point, or number of points.

WARNING: These procedures require the use of specialized

test equipment and calibration adjustments should only be

carried out by qualiﬁ ed personnel.

POINT

-100

-90

-80

-70

-60

Figure 26

REF

-90.0

-80.0

-70.0

-60.0

MDM300

-100.0

-90.0

-80.0

-70.0

-60.0

-100.0

CALIBRATION Page

CALIBRATION

The values in both the corresponding

REF level input) columns can be edited.

REF (reference dew-point) and MDM300 I.S. (reading at the

Section 6 details the use of the calibration routines.

Michell Instruments 31

OPERATION

3.5 Default Parameters

MDM300 I.S. User’s Manual

Parameter Default Value

SETTINGS

PRIMARY DP AT ATMOS DP/TEMP UNIT °C PRESS UNIT psig GAS TYPE AIR MOL WEIGHT N/A CHART INTERVAL 5 sec

LOGGING

FILE NAME PARAMETER DEWP LOG INTERVAL 5 sec

START? STOPPED

BLUETOOTH

ENABLE NO NAME MDM300 I.S.

EXTERNAL

EXTERNAL TYPE NONE EXTERNAL ZERO N/A EXTERNAL SPAN N/A

Associated Section

Reference

Section 3.4.1,

Section 3.4.2,

Section 3.4.3,

Section 3.4.4,

Figure 15

Figure 16

Figure 17

Figure 19

CLOCK

Current UK time & date

HMI

CONTRAST 80% BRIGHTNESS 40% KEYTONE OFF BL TIME-OUT OFF LANGUAGE ENG PRIMARY DISP INTERN

CALIBRATION & INFO

Default values not

applicable

Table 10 MDM300 I.S. Default Parameters

Section 3.4.5,

Section 3.4.6,

Section 3.4.11 & Section 6

Figure 20

Figure 21

32 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

3.6 Guide to Measurement and Sampling

Operating the MDM300 I.S. is very straightforward, but sampling conditions can vary greatly from one application to another. To get the best possible response speed, the appropriate procedure should be followed.

HIGH PRESSURE! High pressure gases are potentially

hazardous. Energy stored in these gases can be released

suddenly and with extreme force. High pressure systems

should be assembled and operated only by people who have

been trained in proper safety practices.

POSSIBLE INJURY! The tubing, valves and other apparatus

attached to this instrument must be adequate for the

maximum pressure which will be applied, otherwise physical

injury to the operator or bystander is possible.

OPERATION

For the most basic measurement it is recommended to have a flow meter (0 to 1 l/min), and at least one metering valve.

A number of sampling kits are available from Michell Instruments:

• The Easi-fit sample kit is a low cost sampling system consisting

of 2 metering valves and a flow meter which is suitable for many applications.

• The MDM300 panel-mount sampling system offers a complete package

for conditioning of a sample, prior to measurement with an MDM300. It is contained within an optional flight case which allows for easy transport of everything required to make the measurements. The antistatic construction of the case makes it suitable for use in hazardous areas.

Figure 27

Specialized kits are available for the measurement of atmospheric pressure samples, compressed air, medical gas and SF6. Contact a Michell Instruments’ representative for more information.

Michell Instruments 33

Easi-Fit Sample Kit MDM300 Panel-Mount Sampling System

OPERATION

It is highly recommended that a ﬁ lter is installed upstream of the MDM300. Refer to the Sample Conditioning section of the

Sampling Hints found in Section 4.1.

3.6.1 Measuring at Atmospheric or System Pressure

Without a metering valve

The large and small orifice fittings can be used to restrict flow at pressures up to 10 barg (145 psig).

To measure at atmospheric pressure, fit the small orifice fitting to the inlet of the instrument. Fit a large orifice fitting to the outlet of the instrument.

To measure at system pressure, fit the small orifice fitting to the outlet of the instrument. Fit a large orifice fitting to the inlet of the instrument.

MDM300 I.S. User’s Manual

Figure 28

With one metering valve

Ensure that large orifice fittings are fitted to both the inlet and the outlet of the instrument.

To measure at atmospheric pressure the metering valve used to control the sample flow should be fitted to the inlet of the instrument.

To measure at system pressure the metering valve used to control the sample flow should be fitted to the outlet of the instrument.

With two metering valves

Ensure that large orifice fittings are fitted to both the inlet and the outlet of the instrument.

To measure at atmospheric pressure the metering valve on the instrument outlet should be fully open. The metering valve on the inlet should be used to control the sample flow.

Large and Small Oriﬁ ce Fitting

To measure at system pressure the metering valve on the instrument inlet should be fully open. The metering valve on the outlet should be used to control the sample flow.

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3.6.2 Measurement Guide

1. Follow procedure A and note the result.

2. Turn the instrument off.

3. If you wish to measure at sample pressure then use the Michell Humidity Calculator (http://www.michell.com/uk/downloads/humidity_calculator. msi) to convert this result back to the equivalent at your sample pressure.

4. Using this converted result, and the table below, find the appropriate procedure to measure your sample.

OPERATION

Measure at

Dew Point

>-40°C Procedure B Procedure A <-40°C Procedure C Procedure A

Table 11 MDM300 I.S. Measurement Procedures

A Standard Purge (Atmospheric Measurement)

1. Connect the MDM300 I.S. to the sample gas stream.

2. Adjust the flow rate, using the inlet flow control valve, to between 0.2

& 0.5 Nl/min (0.5 & 1 scfh). The outlet flow control valve should be fully open.

3. Turn the instrument on - the initialization period begins automatically. The page will show a countdown of the remaining initialization time. The status display will read

Sample Pressure

> 2.5 barg

‘Initializing internal sensor’.

Measure at

Atmospheric Pressure

4. After Initialization, the instrument will begin Measurement mode. During the first few minutes of Measurement mode, the displayed moisture value will drop rapidly below the actual moisture value, before returning to a stable reading. The instrument display will show an initial measured

value, and the status display will show ‘

5. Once ‘ close to the final dew point. Depending on the conditions, it may continue to respond for a number of minutes before tracking the measured dew point.

Measurement in progress’ has disappeared, the instrument is

Measurement in progress’.

Michell Instruments 35

OPERATION

B Standard Purge (Pressure Measurement)

1. Connect the MDM300 I.S. to the sample gas stream.

2. Adjust the flow rate, using the outlet flow control valve, to between

0.2 & 0.5 Nl/min (0.5 & 1 scfh). The inlet flow control valve should be fully open.

3. Turn the instrument on - the initialization period begins automatically. The page will show a countdown of the remaining initialization time. The

status display will read ‘

MDM300 I.S. User’s Manual

Initializing internal sensor’.

Measurement in progress’.

5. Once ‘ close to the final dew point. Depending on the conditions, it may continue to respond for a number of minutes before tracking the measured dew point.

C Enhanced Purge

1. Connect the MDM300 I.S. to the sample gas stream.

2. Adjust the flow rate, using the inlet flow control valve, to between 0.2

& 0.5 Nl/min (0.5 & 1 scfh). The outlet flow control valve should be fully open.

3. Turn the instrument on - the initialization period begins automatically. The page will show a countdown of the remaining initialization time. The

status display will read

4. Once 2-3 minutes of the initialization period have elapsed, close the outlet flow control valve and fully open the inlet flow control valve. Then adjust the flow rate using the outlet flow control valve to between 0.2 & 0.5 Nl/ min (0.5 & 1 scfh).

Measurement in progress’ has disappeared, the instrument is

‘Initializing internal sensor’.

5. After Initialization, the instrument will begin Measurement mode. During the first few minutes of Measurement mode, the displayed moisture value will drop rapidly below the actual moisture value, before returning to a stable reading. The instrument display will show an initial measured value, and the status display will show ‘

6. Once ‘ close to the final dew point. Depending on the conditions, it may continue to respond for a number of minutes before tracking the measured dew point.

Measurement in progress’ has disappeared, the instrument is

Measurement in progress’.

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MDM300 I.S. User’s Manual

3.6.3 Conditional Sensor Purge

In order to ensure consistently fast measurement response speeds after power Off/On, the sensor will not be automatically purged when the measured dew point is deemed to be sufficiently close to the previously measured dew point.

3.7 Battery Management

The battery will typically provide 24 hours of continuous operation from full charge. When the battery approaches discharge, the instrument will display the warning

message ‘

Following this, the instrument will enter a Shutdown Mode, accompanied by an audible beep. This mode will disable the operation of the keypad and display backlight, preventing further usage of the unit. Upon connecting the instrument to the battery charger it will exit Shutdown Mode within 30 seconds.

When Shutdown Mode occurs, connect the instrument to the battery charger as soon as possible to prevent complete discharge. Complete discharge may occur if the unit is not connected to a battery charger within a 24 hour period - see below.

Battery low – recharge now’.

OPERATION

WARNING: If complete discharge does occur, then

difﬁ culties may be encountered when attempting to

If this problem is experienced, refer below for a possible

3.7.1 Battery Troubleshooting

Problem: Instrument battery is flat and will not charge. (NOTE: OLDER FW 7219 MODEL BATTERY CHARGER ONLY).

Cause: If the instrument has been left in a completely discharged state for

several days then it is possible that the FW 7219 charger will not recharge the battery.

Solution: The instrument will need to be connected to a 6 V (500 mA max) power

supply – via its normal charging port – for a maximum of 15 seconds before switching to the FW 7219 charger, which should now behave normally.

recharge the battery.

solution.

DO NOT leave this 6 V power supply connected to the

instrument for any longer than the recommended 15 seconds

or the battery may be damaged.

NOTE: Michell Instruments will replace the older FW 7219 charger with the new Cell Con model free of charge. The Cell Con will re-charge batteries which have completely discharged.

Michell Instruments 37

GOOD MEASUREMENT PRACTICE

4 GOOD MEASUREMENT PRACTICE

The MDM300 I.S. is designed to operate in a flowing gas stream with flow rates between

0.2 and 0.5 Nl/min (0.5 and 1 scfh). Flow regulation is provided with the MDM300 I.S.

instrument between 2.5 and 10 barg. Outside of this, the sample flow must be regulated outside the unit.

For all applications, the sample gas is taken into the instrument via the Gas In port (2)

Figure 5

internal sensor and out via the Gas Out port (1) is normally measured externally, on the output side of the instrument.

There are a number of options for sample conditioning including a purpose built sampling system and a variety of application kits. The flow rate can be regulated on the inlet or outlet depending on whether the intention is to measure at atmospheric or sample pressure. Up to 10 barg, this can be achieved by use of the orifice fittings supplied with the instrument. Section 2.5.1 and non-hazardous gas at atmospheric or elevated pressure.

In applications where the sample gas has a very high flow rate it is advisable to use an instrument by-pass arrangement to provide the minimal flow rates which the sensor requires. Excessive flow restriction can cause back-pressure across the sensor, leading to a discrepancy between the readings recorded and those expected.

located on the top of the instrument, from where it passes through the

Figure 8

MDM300 I.S. User’s Manual

Figure 5

show a typical arrangement for measuring

. Gas flow rate (if monitored)

Note: Dew-point is dramatically affected by changes in pressure - in order to ensure the best performance from the instrument it is essential to adequately regulate the sample pressure.

Ideally, a good quality pressure regulator should be used in conjunction with a fine adjustment needle valve. Using a needle valve exclusively is acceptable, but only if the sample pressure downstream of the nearest regulator is not susceptible to pressure fluctuations greater than ±250 millibar.

Measurement of Dew Points Drier than -70°Cdp

The MDM300 I.S. Sampling System is optimized for fast response. Therefore, when measuring very dry dew points, certain steps need to be taken to ensure that the best accuracy is achieved:

Make sure that all tubing and fittings used are made from stainless steel.

This should reduce the possibility of any moisture being trapped upstream of the sensor prolonging the dry-down process, or permeating into the sample line through unsuitable tubing - such as PTFE.

Due to the significantly lower levels of moisture present at dew points of this level, the response times of the sensor will be significantly increased. The table below offers an approximate guide to the times taken for the instrument to stabilize at a given dew point (from a starting point of 10°Cdp ambient):

Target Dew Point (°C) T100 response time from ambient (hours)

-80 12

-90 48

-100 96

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4.1 Sampling Hints

Measurement of moisture content is a complex subject, but does not need to be difficult. This section aims to explain the common mistakes made in measurement situations, the causes of the problem, and how to avoid them. Mistakes and bad practices can cause the measurement to vary from the expectation; therefore a good sampling technique is crucial for accurate and reliable results.

Transpiration and Sampling Materials

- 20

- 30

GOOD MEASUREMENT PRACTICE

- 40

- 50

Dew point (ºC)

- 60

- 70

12345

nickel

stainless steel

Time (hours)

nylon

copper

polyethylene

PTFE

All materials are permeable to water vapor, as the water molecule is extremely small compared to the structure of solids, even when compared to the crystalline structure of metals. The graph to the right shows the dew point inside tubing of different materials when purged with very dry gas, where the exterior of the tubing is in the ambient environment.

Many materials contain moisture as part of their structure, particularly organic materials (natural or synthetic), salts (or anything which contains them) and anything which has small pores. It is important to ensure that the materials used are suitable for the application.

If the partial water vapor pressure exerted on the outside of a compressed air line is higher than on the inside, the atmospheric water vapor will naturally push through the porous medium causing water to migrate into the pressurized air line. This effect is called transpiration.

Adsorption and Desorption

Adsorption is the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to the surface of a material, creating a film. The rate of adsorption is increased at higher pressures and lower temperatures.

Desorption is the release of a substance from or through the surface of a material. In constant environmental conditions, an adsorbed substance will remain on a surface almost indefinitely. However, as the temperature rises, so does the likelihood of desorption occurring.

In practical terms, as the temperature of the environment fluctuates, water molecules are adsorbed and desorbed from the internal surfaces of the sample tubing, causing small fluctuations in the measured dew point.

Michell Instruments 39

GOOD MEASUREMENT PRACTICE

Sample Tubing Length

The sample point should always be as close to the critical measurement point as possible, in order to obtain a truly representative measurement. The length of the sample line to the sensor or instrument should be as short as possible. Interconnection points and valves trap moisture, so using the simplest sampling arrangement possible will reduce the time it takes for the sample system to dry out when purged with dry gas.

Over a long tubing run, water will inevitably migrate into any line, and the effects of adsorption and desorption will become more apparent. It is clear from the graph shown above that the best materials to resist transpiration are stainless steel and PTFE.

Trapped Moisture

Dead volumes (areas which are not in a direct flow path) in sample lines, hold onto water molecules which are slowly released into the passing gas; this results in increased purge and response times, and wetter than expected readings. Hygroscopic materials in filters, valves (e.g. rubber from pressure regulators) or any other parts of the system can also trap moisture.

MDM300 I.S. User’s Manual

Sample Conditioning

Sample conditioning is often necessary to avoid exposure of sensitive measuring components to liquids and other contaminants which may cause damage or affect the accuracy over time, depending on the measurement technology.

Particulate filters are used for removing dirt, rust, scale and any other solids that may be in a sample stream. For protection against liquids, a coalescing filter should be used. The membrane filter is a more expensive but highly effective alternative to a coalescing filter. It provides protection from liquid droplets, and can even stop flow to the analyzer completely when a large slug of liquid is encountered.

Condensation and Leaks

Dewpoint > T Dewpoint < T

Maintaining the temperature of the sample system tubing above the dew point of the sample is vital to prevent condensation. Any condensation invalidates the sampling process as it changes the water vapor content of the gas being measured. Condensed liquid can alter the humidity elsewhere by dripping or running to other locations where it may re-evaporate.

The integrity of all connections is also an important consideration, especially when sampling low dew points at an elevated pressure. If a small leak occurs in a high pressure line, gas will leak out but vortices at the leak point and a negative vapor pressure differential will also allow water vapor to contaminate the flow.

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MDM300 I.S. User’s Manual

Flow Rates

Theoretically flow rate has no direct effect on the measured moisture content, but in practice it can have unanticipated effects on response speed and accuracy. The optimal flow rate varies depending on the measurement technology, and can always be found in the instrument or sensor manual.

An inadequate flow rate can:

• Accentuate adsorption and desorption effects on the gas passing

through the sampling system.

• Allow pockets of wet gas to remain undisturbed in a complex sampling

system, which will then gradually be released into the sample flow.

• Increase the chance of contamination from back diffusion: ambient air

that is wetter than the sample can flow from the exhaust back into the system. A longer exhaust (sometimes called a pigtail) can also help alleviate this problem.

GOOD MEASUREMENT PRACTICE

• Slow the response of the sensor to changes in moisture content.

An excessively high flow rate can:

• Introduce back pressure, causing slower response times and

unpredictable effects on equipment such as humidity generators.

• Result in a reduction in heating capabilities of the sensor tile during

the initialization period. This is most apparent with gases that have a high thermal conductivity such as hydrogen and helium.

POSSIBLE INJURY! The tubing, valves and other apparatus

attached to this instrument must be adequate for the

maximum pressure which will be applied, otherwise physical

injury to the operator or bystander is possible.

Before disconnecting the MDM300 I.S. from the gas line

it is essential to vent the system to atmospheric pressure,

otherwise severe injury could result.

Michell Instruments 41

APPLICATION SOFTWARE

5 APPLICATION SOFTWARE

Application software for the MDM300 I.S. is supplied on a CD.

The latest version of this application software is also available for download from the Michell website – http://www.michell.com/uk/support/sware-downloads.htm.

To install on a PC: place the CD in the CD drive and follow the instructions in the application set-up wizard. If the CD does not auto-run, double-click the application set-up file on the CD. The following authorization code will be required during the

installation process:

Once the software has been installed and run, the MDM300 I.S. can be linked to the PC by activating the Bluetooth on the MDM300 I.S. and then connecting with the application software (see Section 3.4.3 for details).

The application software allows modification of all the instrument parameters from the connected PC. The settings currently stored on the MDM300 I.S. can be downloaded to

the PC by clicking the ‘ stored by clicking the ‘

MDM-300-7392

Download from MDM300’ button, and can then be changed and

Upload to MDM300’ button.

MDM300 I.S. User’s Manual

The software gives access to all logging files stored on the instrument’s internal memory. These can be downloaded to a specific location by right clicking, and selecting

download’.

‘

A context sensitive help file provides further details on the use of the application software.

Figure 29

Typical Application Software Screen

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MDM300 I.S. User’s Manual

6 CALIBRATION

6.1 Traceability

The calibration of this instrument is traceable to national standards. For this reason the instrument should only be calibrated in an accredited, e.g. UKAS or NIST (U.S.) standards laboratory.

If these facilities do not exist it is recommended that the instrument be returned to the manufacturer, Michell Instruments Ltd., or one of the approved agents.

A calibration certificate bearing a seven point calibration is issued with each instrument.

CALIBRATION

Figure 30

shows a typical seven point calibration certificate.

Figure 30

Typical 7-point Calibration Certiﬁ cate

Michell Instruments 43

CALIBRATION

6.2 Calibration Method

equipment and calibration adjustments should only be carried

out by qualiﬁ ed personnel. If not correctly carried out, the

The calibration procedure for the instrument is as follows:

1. Switch on the instrument. Wait for the initialization period to complete and allow sufficient time for it to stabilize.

MDM300 I.S. User’s Manual

WARNING:

These procedures require the use of specialized test

instrument’s calibration can be lost.

2. Ensure the instrument is set up with sample gas as

ATMOS.

3. Ensure that the temperature units are set up as reading

4. Ensure that all sample tubing and connectors are made from stainless steel and are of suitable quality.

5. Connect the MDM300 I.S. to a dew-point generator and establish a gas flow through the instrument.

6. Apply a dew point of -100°C and allow the instrument’s reading to stabilize for a minimum of 96 hours (including dry down).

7. Record the applied reading.

8. Repeat steps 6 and 7 at all the required dew-point values over the operating range of the instrument, as shown in Table 12, allowing the stabilization times shown before recording consecutive readings.

A set of results similar to that shown below could be generated over the calibration range of the instrument.

Dew point.

REF dew point and the corresponding MDM300 I.S. display

AIR and operating pressure

°C and the primary display is

DP REF

°C

-100 96 -99.8 -30 1 -30.1

-80 12 -79.7 -20 1 -19.9

-70 8 -70 -10 1 -10

-60 4 -59.8 0 1 0.1

-50 2 -49.8 10 1 10

-40 1 -39.9 20 1 20

Stabilize

Time

(Hours)

Table 12 Example Of Calibration Run Readings

MDM300 I.S.

Rdg °C

DP REF

°C

Stabilize

Time

(Hours)

MDM300 I.S.

Rdg °C

44 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

6.3 Calibration Correction Method

NOTE: Any logging procedure currently in operation must be cancelled before the calibration procedures can be entered.

CALIBRATION

To enter the CALIBRATION Menu page, highlight

CALIBRATION from the SET-UP Menu

by using the  or  keys and press the Enter key.

Entry to the CALIBRATION Menu is protected by a passcode (

4876).

Once the passcode has been successfully entered, the following page will be shown.

POINT

-100

-90

-80

-70

-60

Figure 31

REF

-100.0

-90.0

-80.0

-70.0

-60.0

MDM300

-100.0

-90.0

-80.0

-70.0

-60.0

CALIBRATION

Calibration Menu Page

The MDM300 I.S. Calibration look-up table is divided into three columns.

The values in the first column

POINT represent the thirteen nominal calibration points,

spread at 10°C intervals over the instruments operating range of -100 to +20°C (-148 to +68°F). These points cannot be edited.

The second column

REF represents the value of the reference dew-point standard

applied at that particular point.

The third column at the corresponding

The values in both the

and  keys. The  and  keys provide the means of switching between corresponding



MDM300 represents the reading that the MDM300 I.S. was showing

REF level input.

REF and MDM300 I.S. columns can be edited by means of the

table columns.

After changes have been made press the

Enter key to reach the Exit page. No changes

are implemented until the  key is pressed at the Exit page.

To exit without implementing any changes, press the

Enter key to reach the Exit page.

Press the  key, from the Exit page, to return to the SET-UP Menu.

Michell Instruments 45

SHIPPING

MDM300 I.S.

Advanced Dew-Point Hygrometer

User’s Manual

- I.S.

97213 Issue 4

September 2012

7 SHIPPING

For shipping purposes the instrument should be packed into its original carton which will provide the recommended degree of protection during transit.

To prepare the instrument for shipping, proceed as follows:

1. Switch the instrument off and remove any connections to the Gas In and Gas Out ports and any external sensors connected to it.

2. If fitted, remove the instrument from its carrying case.

3. Pack the instrument in its original carton (1) as shown below.

NOTE: It is not necessary to return any accessories unless they require repair/replacement. Any returned accessories can be packed in the box (4).

4. Create a packing list detailing all equipment contained in the box, place it inside the box and seal the box.

MDM300 I.S. User’s Manual

Before disconnecting the MDM300 I.S. from the gas line it is essential to

vent the system to atmospheric pressure, otherwise severe injury could

result.

er 08

r 08

00 Issue 1 Octob

000

00000 Issue 1 Octobe

- I.S.

Figure 34

46 97213 Issue 5, October 2017

Instrument Packing Details

MDM300 I.S. User’s Manual

APPENDIX A

Appendix A

Technical Speciﬁ cations

Michell Instruments 47

APPENDIX A

Appendix A Technical Speciﬁ cations

Performance

Measurement Technology Michell Ceramic Sensor

±1°C from -60 to +20°Cdp (-76 to +68°Fdp)

Accuracy

±2°C from -100 to -60°Cdp (-148 to -76°Fdp) ±0.2°C (0.3°F) temperature

MDM300 I.S. User’s Manual

Calibrated Measurement Range

Uncalibrated Readings From +20 to +30°Cdp (+68 to +86°Fdp)

Measurement Units

Pressure Units psig, barg, KPa, bara, psia, MPa

Resolution (display) 0.1 for all dew-point derived units & auto ranging where appropriate

Resolution (measurement) Better than 0.1°Cdp (0.2°Fdp)

Typical Response Speed T95 in ≤30 minutes to -60°Cdp (-76°Fdp)

Sample Gas Flow 0.2 to 0.5 Nl/min (0.5 to 1 scfh)

For Spot Checks -70 to +20°Cdp (-95 to +68°Fdp) For Online Analysis -100 to -70°Cdp (-148 to -95°Fdp)

°C, °F, K dew point & gas temperature % RH, ppm ppmW & g/kg (for air, N2, H2, CO2, SF6, user-deﬁ ned mw) ppmV, lb/mmscf & g/m3 for natural gas

, g/m

Electrical Speciﬁ cations

Auxiliary Inputs

Battery 4.8 V internally mounted Nickel Metal Hydride (NiMH) battery

Battery Operating Life Up to 24 hours of typical usage between charges

Connection to Michell Easidew I.S. or Easidew PRO I.S. via Remote Sensor Interface

Battery Charger

Intelligent charger, NOT certiﬁ ed for hazardous area use Charger supply voltage: 100 to 240 V AC, 50/60 Hz, 8 VA

Operating Conditions

Operating Pressure 0 to 35 MPa (0 to 350 barg / 0 to 5076 psig)

Operating Environment Outdoors 0 to +100% RH (non-condensing)

Operating Temperature -20 to +50°C (-4 to +122°F)

Storage / Transport Temperature -40 to +70°C (-40 to +158°F)

Altitude Up to 2000m (6562ft)

Mechanical Speciﬁ cations

Display Blue LCD graphical display

Enclosure Type Steel ﬁ ber-loaded high-impact polyamide 6

IP/NEMA Rating IP66/NEMA 4

Gas Connections 1/8” NPT female (other options available)

Gas Wetted Materials AISI 316L stainless steel, PTFE Seal, Borosilicate glass, ceramic

Outline Dimensions 218 x 170 x 90mm (8.6 x 6.7 x 3.5ft) (d x w x h)

Weight 1.5kg (3.3lbs)

48 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

Capacity: 8Mb

Data Logging

Communications (Wireless) Bluetooth

Languages English, German, Spanish, French, Italian, Portuguese

Hazardous Area Certiﬁ cation

Certiﬁ cation Codes

A.1 Dimensions

Log interval: 5 to 60 sec Maximum log ﬁ le size: 60kb

range up to 5m (16ft) (Version 2.0)

ATEX II 1G Ex ia IIC T4 Ga (-20°C to +50°C) IECEx Ex ia IIC T4 Ga (-20°C to +50°C) INMETRO Ex ia IIC T4 Ga (-20°C to +50°C) TC TR Ex 0Ex ia IIC T4 Ga FM Class I, Division 1, Groups A B C D, T4 CSA Class I, Division 1, Groups A B C D, T4

APPENDIX A

218mm (8.56”)

Figure 35

170mm (6.69”)

90mm (3.54”)

Dimensions - MDM300 I.S.

Michell Instruments 49

APPENDIX B

MDM300 I.S. User’s Manual

Appendix B

Datalog Status Display

50 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

Appendix B Datalog Status Display

APPENDIX B

When the status of the current log file is displayed, see the current log file display represents the instrument’s status at the time that each log point is recorded.

106 107 108 109 110

This column shows a hexadecimal representation of the instrument’s 16-bit status register shown below in significant bits 13 to 16 are for Michell Instruments’ service use and so the first character in any MDM300 I.S. ST display will always read 0.

INT

26.8

26.2

25.9

25.8

25.5

EXT

-100.0

-90.0

-80.0

-70.0

-60.0

Figure 36

0028 0028 0028 0028 0028

Current Datalog File Display

. Bit 1 is the least significant bit. The four most

File CR270309 INT RH EXT. EXT_DP INTVAL 05 Sec D# 090327 T# 123606

Figure 33

, the ST column in

Status register bit position

16151413121110987654321

N/A N/A N/A N/A

For the example given for each of the log plots shown in output pattern of the status register will be as shown in

16151413121110987654321

N/A N/A N/A N/A

0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 N/A

Figure 37

Status register bit position

00000010100N/A

Figure 38

MDM300 I.S. Status Register (Hex 28)

MDM300 I.S. Status Register

Figure 35

Figure 37

(Hex 0028), the

Each of the error bits set high (1) represents a specific status or error condition. In this example, bits 4 and 6 are set high indicating that two (status) conditions exist.

Michell Instruments 51

APPENDIX B

Table 13 shows the status flags associated with each bit of the status register. If a status flag is set high then the associated condition exists. If it is set low, then that condition does not exist.

MDM300 I.S. User’s Manual

Status Register bit in Hex

0x0002 = BIT 2

0x0004 = BIT 3

0x0008 = BIT 4

0x0010 = BIT 5

0x0020 = BIT 6

0x0040 = BIT 7

0x0080 = BIT 8

0x0100 = BIT 9

0x0200 = BIT 10

0x0800 = BIT 12

Message Details

Internal sensor error

Internal thermistor error

External sensor error

Battery low Measurement in

progress

Log  nished

Internal sensor not found

Default CONFIG  le used

Initializing Internal Sensor

Dew-point reading out of range (> +30 / <

-120°C)

Sensor internal temperature reading out of range (> +100 / < -40°C) or Thermistor fault

External Sensor Input out of range (< 4 mA / > 20 mA)

Battery level low - recharge as soon as possible

Internal dew point not stable

Internal dew point changing <0.2°Cdp over a 3 minute interval

Log ﬁ le has reached the maximum of 10,000 logs and logging has been stopped

Could not detect internal sensor on power up

Conﬁ g. ﬁ le missing, new ﬁ le created and default settings used

Indicates system in purging phase

Table 13 Status Register Flags

For the example given in to left, as bit 4 set ‘

Therefore, at the time that these log points were taken, the external sensor was out of range and the internal dew point was not stable.

Figure 35

External sensor error’ and bit 6 set ‘Measurement in progress’.

, from Table 13, Hex 28 translates, reading from right

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MDM300 I.S. User’s Manual

APPENDIX C

Appendix C

Hazardous Area

Certiﬁ cation

Michell Instruments 53

APPENDIX C

Appendix C Hazardous Area Certiﬁ cation

The MDM300 I.S is certified compliant to the ATEX Directive (2014/34/EU) and IECEx for use within Zone 0 Hazardous Area, and has been assessed so by Baseefa Ltd (Notified Body 1180).

The MDM300 I.S is certified compliant to North American Standards (USA and Canada) for use within Class I, Division 1, Groups A, B, C & D Hazardous Locations and has been assessed so by CSA and FM.

C.1 Product Standards

This product conforms to the Standards:

EN60079-0:2009 IEC60079-11:2006 EN60079-26:2007 IEC60079-0:2007-10 EN60079-11:2007 IEC60079-26:2006 CAN/CSA-C22.2 No.0-M10 FM CLASS 3600:1998 CAN/CSA-C22.2 No. 157-92(R2012) FM CLASS 3610:2010 CAN/CSA-C22.2 No.142-M1987(R2009) FM CLASS 3810:2005 ANSI/IEC 60529:2004

MDM300 I.S. User’s Manual

C.2 Product Certiﬁ cation

This product is attributed with the product certification codes:

ATEX & IECEx II 1 G Ex ia IIC T4 Ga (-20°C to +50°C)

North American IS - Class I, Division 1, Groups A, B, C, D, T4

C.3 Global Certiﬁ cates/Approvals

ATEX BASEEFA09ATEX0149 IECEx IECEX BAS09.0063 FM 3036712 CSA 2318983 TC TR Ex RU C-GB. ГБ05.B.00229 INMETRO NCC14.03165

These certificates can be viewed or downloaded from our website at: http://www.michell.com

C.4 Input Terminal Parameters

External Sensor Socket Charging Socket

= 28 V U

= 93 mA

= 650 mW

= 18V

PO = 0

= 0

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MDM300 I.S. User’s Manual

C.5 Special Conditions of Use

None

C.6 Maintenance and Installation

The MDM300 I.S. must only be installed by suitably qualified personnel and in accordance with the instructions provided and the terms of the applicable product certificates.

Maintenance and servicing of the product must only be carried out by suitably trained personnel or returned to an approved Michell Instruments’ Service Center.

APPENDIX C

Michell Instruments 55

APPENDIX D

MDM300 I.S. User’s Manual

Appendix D

FCC Declaration

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MDM300 I.S. User’s Manual

Appendix D FCC Declaration

APPENDIX D

MDM300 I.S. Advanced Dewpoint Hygrometer.

This Device complies with FCC Rules Part 15 Subpart B Unintentional Radiators Class B digital devices. Operation is subject to the following conditions:

1) This device may not cause harmful interference

2) This device must accept any interference received, including interference that may cause

undesired operation.

Note: This product has been tested and found to comply with the limits or Class B digital devices, pursuant to Part 15 of the FCC rules. This product generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not in a particular installation. If this product does cause harmful interference to radio reception, which may be determined by turning the product on & off, the user is encouraged to try to correct the interference by one or more of the following measures:

Reorient or relocate the receiving antenna, Increase the separation between the product and receiver, Connect the equipment into an outlet on a circuit different from that to which the receiver is

connected

Consult the dealer or an experienced radio/TV technician for help.

This product must be operated as per the operating instructions provided. Do not make any alterations or modifications to the product. Any unauthorised alterations or modifications made to this product may require you to stop operating the product.

Canadian Radio Interference Regulations. This Class B digital product complies with Canadian ICES-003, CISPR 22 :1997. Règlement canadien sur les interférences radio. Ce produit numérique de classe B est conforme à la norme NMB-003, CISPR 22: 1997.

Signed for, and on behalf of, Michell Instruments Ltd.

Andrew M.V. Stokes, Technical Director

Issue date: 05/2011

Michell Instruments 57

APPENDIX E

MDM300 I.S. User’s Manual

Appendix E

Quality, Recycling

& Warranty

Information

58 97213 Issue 5, October 2017

MDM300 I.S. User’s Manual

APPENDIX E

Appendix E Quality, Recycling & Warranty Information

Michell Instruments is dedicated to complying to all relevant legislation and directives. Full information can be found on our website at:

www.michell.com/compliance

This page contains information on the following directives:

• ATEX Directive

• Calibration Facilities

• Conflict Minerals

• FCC Statement

• Manufacturing Quality

• Modern Slavery Statement

• Pressure Equipment Directive

• REACH

• RoHS2

• WEEE2

• Recycling Policy

• Warranty and Returns

This information is also available in PDF format.

Michell Instruments 59

APPENDIX F

MDM300 I.S. User’s Manual

Appendix F

Return Document &

Decontamination Declaration

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MDM300 I.S. User’s Manual

APPENDIX F

Appendix F Return Document & Decontamination Declaration

'HFRQWDPLQDWLRQ&HUWL¿FDWH

IMPORTANT NOTE: Please complete this form prior to this instrument, or any components, leaving your site and being returned to us, or, where applicable, prior to any work being carried out by a Michell engineer at your site.

Instrument Serial Number Warranty Repair? YES NO Original PO # Company Name Contact Name

Address

Telephone # E-mail address Reason for Return /Description of Fault:

Has this equipment been exposed (internally or externally) to any of the following? Please circle (YES/NO) as applicable and provide details below

Biohazards YES NO Biological agents YES NO Hazardous chemicals YES NO Radioactive substances YES NO Other hazards YES NO Please provide details of any hazardous materials used with this equipment as indicated above (use continuation sheet

if necessary)

Your method of cleaning/decontamination

Has the equipment been cleaned and decontaminated? YES NOT NECESSARY Michell Instruments will not accept instruments that have been exposed to toxins, radio-activity or bio-hazardous

PDWHULDOV)RUPRVWDSSOLFDWLRQVLQYROYLQJVROYHQWVDFLGLFEDVLFÀDPPDEOH RUWR[LFJDVHVDVLPSOHSXUJHZLWKGU\ JDVGHZSRLQW&RYHUKRXUVVKRXOGEHVXI¿FLHQWWRGHFRQWDPLQDWHWKHXQLWSULRUWRUHWXUQ

Work will not be carried out on any unit that does not have a completed decontamination declaration.

Decontamination Declaration

I declare that the information above is true and complete to the best of my knowledge, and it is safe for Michell personnel to service or repair the returned instrument.

Name (Print) Position

Signature Date

F0121, Issue 2, December 2011

Michell Instruments 61

NOTES:

MDM300 I.S. User’s Manual

62 97213 Issue 5, October 2017

http://www.michell.com

Michell Instruments MDM300-IS Operating Manual

Specifications and Main Features

Frequently Asked Questions

User Manual