Michell Instruments Liquidew EExd User manual

Liquidew EExd
Process Moisture Analyzer
User’s Manual
97097 Issue 14.1
November 2019

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© 2019 Michell Instruments
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.
Liquidew EExd
For Michell Instruments' contact information please go to
www.michell.com

Liquidew EExd User’s Manual
iv 97097 Issue 14.1, November 2019
1 INTRODUCTION ................................................................................................1
1.1 General .............................................................................................................. 1
1.2 Liquid Sample Path ............................................................................................. 1
1.3 Operating Overview ............................................................................................ 2
1.4 User Display and Interface .................................................................................. 2
1.5 Advanced Sensor Technology .............................................................................. 2
1.6 Measurement Units ............................................................................................. 2
1.7 Elimination of Temperature Effects ....................................................................... 3
1.8 Calibration ........................................................................................................ 3
1.9 Liquidew EExd Sampling System .......................................................................... 4
2 INSTALLATION ..................................................................................................5
2.1 Electrical Safety .................................................................................................. 5
2.1.1 Equipment Ratings and Installation Details ...................................................... 5
2.2 Hazardous Area Safety ........................................................................................ 8
2.3 Pressure Safety .................................................................................................. 9
2.4 Lifting and Handling ........................................................................................... 9
2.5 Analyzer System ............................................................................................... 10
2.5.1 Pipework ................................................................................................... 11
2.5.2 Power Connections ...................................................................................... 12
2.5.3 Analog and Digital Communications ............................................................. 13
2.5.4 Process Alarms and Analyzer Status Alarms .................................................. 13
2.6 Liquidew EExd Start-up Purge Procedure ............................................................ 14
2.7 Sample Flows ................................................................................................... 15
3 OPERATION ....................................................................................................16
3.1 System Operation ............................................................................................. 16
3.2 User Interface .................................................................................................. 16
3.2.1 Interface Controls ....................................................................................... 16
3.2.2 ‘Up/Down Arrow’ Buttons ............................................................................. 17
3.2.3 ‘SELECT’ Button .......................................................................................... 17
3.2.4 ‘MENU/MAIN’ Button ................................................................................... 17
3.3 Menu Structure ................................................................................................ 18
3.4 MAIN MENU Page ............................................................................................. 19
3.5 STATUS Page ................................................................................................... 19
3.6 LOGGING MENU Page ....................................................................................... 20
3.6.1 VIEW LOGGED DATA Page ........................................................................... 20
3.6.2 VIEW STATISTICS ....................................................................................... 21
3.6.3 VIEW SYSTEM FAULTS Page ........................................................................ 21
3.7 VIEW/ADJ VARIABLES Page .............................................................................. 22
3.7.1 Password .................................................................................................... 22
3.7.2 VARIABLES Pages ....................................................................................... 22
3.7.3 Single Channel Configuration Variables Pages ................................................ 23
3.7.4 Dual Channel Configuration Variables Pages .................................................. 24
3.7.5 User-Defined Solutes ................................................................................... 25
Contents
Safety ...............................................................................................................................vii
Electrical Safety ..........................................................................................................vii
Pressure Safety ...........................................................................................................vii
Toxic Materials ............................................................................................................vii
Repair and Maintenance ..............................................................................................vii
Calibration (factory validation) .....................................................................................vii
Safety Conformity .......................................................................................................vii
Abbreviations .................................................................................................................... viii
Warnings .......................................................................................................................... viii

Liquidew EExd User’s Manual
Michell Instruments v
3.7.5.1 Editing the Table of Cs Values ................................................................ 25
3.7.5.2 Editing the Label for the User-defined Solute .......................................... 25
3.8 SENSOR INFO Page ......................................................................................... 26
3.9 CONTACT INFO Page ....................................................................................... 26
4 MAINTENANCE ................................................................................................27
4.1 Enclosure Cover and User Interface ................................................................... 27
4.2 Replacement of the Sensor Assembly ................................................................. 28
4.3 Replacement of the Flow Meter ......................................................................... 30
4.4 Troubleshooting ................................................................................................ 31
4.4.1 Error Messages ........................................................................................... 31
4.4.2 Error Messages Flashing over Displayed Values ............................................. 31
4.4.3 Logged Error Codes ..................................................................................... 32
4.4.4 Analyzer Fault Alarm Relay ........................................................................... 33
Figures
Figure 1 Liquidew EExd Sampling System ..................................................................4
Figure 2 Power Connection Connector .......................................................................5
Figure 3 Earthing Stud And Nut Washer Assembly .....................................................6
Figure 4 Liquidew EExd Dimensions ........................................................................10
Figure 5 Pipework Connections ...............................................................................11
Figure 6 Hook-up Wiring Diagram ...........................................................................13
Figure 7 Minimum Requirements for Start-up Purging ..............................................15
Figure 8 MAIN Page in Single Channel (top) and Dual Channel Modes .......................16
Figure 9 User Interface ..........................................................................................16
Figure 10 Up/Down Arrow Buttons ...........................................................................17
Figure 11 ‘SELECT’ Button ........................................................................................17
Figure 12 ‘MENU/MAIN’ Button .................................................................................17
Figure 13 Menu Structure ........................................................................................18
Figure 14 MAIN MENU Page .....................................................................................19
Figure 15 STATUS Page ...........................................................................................19
Figure 16 LOGGED DATA Page .................................................................................20
Figure 17 STATISTICS Page .....................................................................................21
Figure 18 SYSTEM FAULTS Page ...............................................................................21
Figure 19 PASSWORD Page ......................................................................................22
Figure 20 VARIABLES Pages (Examples) ...................................................................23
Figure 21 SENSOR INFO Page ..................................................................................26
Figure 22 CONTACT INFO Page ................................................................................26
Figure 23 Ribbon Cable Connection ..........................................................................28
Figure 24 Moisture Sensor Assembly Replacement .....................................................29
Figure 25 Flow Meter Replacement ...........................................................................30
Figure 26 Error Message Line ...................................................................................31
Figure 27 Logged Error Codes ..................................................................................32
Figure 28 Mounting Drawing ....................................................................................37
Figure 29 Pipework Connections ...............................................................................38
Figure 30 System Wiring Diagram .............................................................................39
Figure 31 Calibration Correction Data........................................................................49
Figure 32 Reading Holding Registers State Diagram ...................................................64
Figure 33 Write Single Register State Diagram ...........................................................66

Liquidew EExd User’s Manual
vi 97097 Issue 14.1, November 2019
Appendices
Appendix A Technical Specification ...............................................................................35
A.1 Mounting Drawing .......................................................................37
A.2 Pipework Connections .................................................................. 38
A.3 System Wiring Diagram ................................................................39
Appendix B Variable Definitions ....................................................................................41
Appendix C Software ...................................................................................................46
C.1 System Requirements ..................................................................46
Appendix D Calibration Correction ................................................................................48
D.1 Overview .................................................................................... 48
D.2 Calibration Software ..................................................................... 49
D.3 Calibration Procedure ................................................................... 50
Appendix E Modbus RTU Communications .................................................................... 53
E.1 Introduction ................................................................................ 53
E.2 Modbus RTU Basics ......................................................................53
E.3 Physical Layer ............................................................................. 53
E.4 Termination Resistor ....................................................................54
E.5 Register Map ...............................................................................54
Appendix F Modbus RTU Details ..................................................................................63
F.1 Message Framing .........................................................................63
F.2 Implemented Functions ................................................................64
F.3 Exceptions ..................................................................................68
Appendix G Register Number Formats...........................................................................70
Appendix H Hazardous Area Certification ...................................................................... 75
H.1 Product Standards ......................................................................75
H.2 Product Certification ................................................................... 75
H.3 Global Certificates/Approvals .......................................................75
H.4 Special Conditions of Use ............................................................. 76
H.5 Maintenance and Installation ........................................................76
Appendix I Quality, Recycling & Warranty Information ................................................... 78
Appendix J Return Document & Decontamination Declaration ........................................ 80

Liquidew EExd User’s Manual
Michell Instruments vii
Safety
This manual contains all the required information to install, operate and maintain the Liquidew EExd. Prior
to installation and use of this instrument, this entire manual should be read and understood. Installation
and operation of this product should be carried out by suitably competent personnel only. The operation
of this product must be in accordance with the terms of this manual and associated safety certificates.
Incorrect installation and use of this product for other than its intended purpose will render all warranties
void.
This product is intended for use in a Hazardous Area and is awarded an ATEX, IECEx and CSA Certificate.
The relevant certificates should be fully examined prior to installation or use of this product.
!
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 and where particular attention to
personal and personnel safety must be observed.
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 input power supply voltage limits are 90 to 260 V AC,
47/63 Hz.
Pressure Safety
DO NOT permit pressures greater than the safe working pressure to be applied directly to the instrument.
Refer to the Technical Specifications in Appendix A.
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 only be maintained either by the manufacturer or an accredited service agent. Refer
to www.michell.com for details of Michell Instruments’ worldwide offices contact information.
Calibration (factory validation)
Prior to shipment, the analyzer undergoes stringent factory calibration to internationally traceable
standards, NPL (UK) and NIST (USA). Due to the inherent stability of the instrument, only periodic
calibration is required under normal operating conditions.
Michell Instruments recommends that calibration of the sensor should be maintained on a 12 monthly
basis to ensure optimum operation. Michell Instruments offers a calibration exchange program, where
a refurbished and re-certified sensor is supplied as an operational replacement and the original item
returned to Michell to complete the exchange.
NOTE: This interval may need to be reduced if the operation of the sensor is within potentially
aggressive or corrosive sample media (such as sour natural gas). The calibration interval
may therefore need to be shortened to 6 months (or lower in extreme cases) in order to
maintain satisfactory analyzer performance.
Safety Conformity
This product meets the essential protection requirements of the relevant EU directives.

Liquidew EExd User’s Manual
viii 97097 Issue 14.1, November 2019
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
°C degrees Celsius
°F degrees Fahrenheit
dp dew point
EU European Union
GPM gallons per minute
Hz Hertz
IEC International Electrotechnical Commission
kg kilogram
l/min liters per minute
ml/min milliliters per minute
l/min normal liters per minute
lb pound
mA milliampere
max maximum
min minute(s)
mV millivolt(s)
N/C normally closed
N/O normally open
No number
ppmW parts per million (by weight)
psig pound(s) per square inch (gauge)
RH relative humidity
RTU Remote Terminal Unit
temp temperature
V Volts
" Inch
Warnings
The following general warnings listed below are applicable to this instrument. They are
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.
DANGER
Electric
Shock Risk
Where this symbol appears in the following
sections it is used to indicate areas of
potential risk of electric shock.

Liquidew EExd User’s Manual
Michell Instruments 1
INTRODUCTION
1 INTRODUCTION
1.1 General
The Liquidew EExd is designed for continuous, automatic measurement of the moisture
content in hydrocarbon solutes, utilizing the Michell Ceramic Moisture Sensor. It is the
result of more than 30 years' experience in the supply of analyzers to the worldwide oil,
gas and petrochemical industry.
The analyzer comprises either a single or a dual channel moisture measurement sensor
cell, control electronics and a display interface housed in an Exd enclosure. The analyzer
is ATEX Directive, IECEx or cCSAus compliant for use in a Zone 1 or 2 Hazardous Area
and Class I, Div 1 Hazardous Location. See marking label located on right hand side of
analyzer to identify approvals. An accompanying sample handling panel, designed to be
positioned close to the process sample point to prepare the sample prior to entry into
the Liquidew EExd, can also be supplied.
The instrument offers several user-selectable display options based on a calibrated
dew-point measurement range of -100 to +20°C (-148 to +68°F), traceable to the
humidity metrology standards of NPL (UK) and NIST (USA). The instrument provides
indication in moisture in liquids (ppmW).
The requirements for operation are a 90 to 260 V AC, 47/63 Hz power supply of 180W
and field communications Modbus RTU and/or 4-20 mA. Refer to the System Wiring
Diagram in Appendix B.3.
1.2 Liquid Sample Path
The Liquidew EExd analyzer system must be supplied with a liquid sample at a pressure
up to 80 barg (1160 psig), via a sample handling panel providing filtration & flow
control. Sufficient differential pressure will be required (typically greater than 0.5 barg
(7.2 psig)) between the process sample source and return points. This should enable a
flow between 0.1 and 0.3 l/min (0.03 and 0.08 GPM) through the Liquidew EExd and its
associated sampling system. Sample entry and exit ports direct the liquid through flame
arrestors which, along with the Exd enclosure, provide the explosion proof protection.
The measurement system components are housed within a cast aluminum Exd rated
enclosure. The enclosure has a screw cover incorporating a sealed window. It is
chromate primed, polyester coated in black, and provides environmental protection to
IP66/NEMA 4. An enclosure breather is fitted in the form of an additional flame arrestor.
It is important that no pipe connection is made to this breather and that no restriction
is allowed to occur.
For accuracy and long term reliability, the temperature of the sample entering the
Liquidew EExd should be less than +40°C (+104°F) and higher than +10°C (+50°F).
The sample and operating temperature must not exceed the T ambient rating of +60°C
(+140°F).
All sample wetted metallic parts are manufactured in AISI 316L stainless steel with
Viton soft parts that comply with the NACE standard MR-01-75 (latest edition). Tube
fittings are twin ferrule compression type. All electrical and liquid connections are made
through the base of the enclosure. Refer to the Mounting Drawing in Appendix A.1.
Flow components for Channels 1 & 2 comprise the following:
Flow Meter: Provides indication of low, OK or high flow that is present
throughout the sample measurement stream.
Measurement Cell: The point of measurement that incorporates the Michell Ceramic
Moisture Sensor.

Liquidew EExd User’s Manual
297097 Issue 14.1, November 2019
INTRODUCTION
1.3 Operating Overview
The system continually measures moisture and temperature in an uninterrupted liquid
sample flow rate. Moisture content is determined in part per million by weight (ppmW)
through Henry’s Law, from the measured dew-point temperature and liquid temperature.
It uses an extensive list of saturation concentration data pre-programmed for a variety
of petrochemical liquids, with provision for easy entry of ‘custom’ characteristics data
by the user.
Moisture and temperature for each channel are logged at a user-defined interval. The
logs are available through the user interface or via the serial communications. Two
4–20 mA outputs for each channel are available to remotely read the humidity and
temperature in real time.
1.4 User Display and Interface
The Liquidew EExd User Display and Interface Unit is presented via the circular window
of the enclosure. Operation is achieved by a unique system, which allows full control
through the glass of the enclosure cover. The cover is fully detachable for greater
access into the enclosure during the installation and initial set-up of the instrument.
During normal operation of the instrument the cover must remain fully secured.
1.5 Advanced Sensor Technology
Liquidew EExd utilizes the Michell Ceramic Moisture Sensor, an advanced impedance
sensor technology, with integrated temperature measurement. This sensor is used in
more than 1,000 natural gas and petrochemical installations worldwide.
Semiconductor thick- and thin-film technologies combine in metallized ceramics,
producing an exceedingly durable sensor with the physical resilience to provide long-
term reliable service in liquid phase measurements.
The Ceramic Sensor responds to the partial pressure of water vapor in the fluid being
measured, which is directly related to the dew-point temperature. Every Liquidew EExd
sensor is calibrated against fundamental dew-point measurement systems in Michell’s
laboratory, which is internationally accredited and directly traceable to both NPL(UK)
and NIST(USA) metrology standards.
1.6 Measurement Units
The hygrometric unit can be set by the user to °C/°F dew point or moisture content in
ppmW.
The advanced firmware of the Liquidew EExd provides moisture measurements in ppmW
through the application of Henry’s Law. It uses pre-programmed saturation concentration
(Cs) values for the following common pure hydrocarbon liquid applications:
Hexane, Propane, Isopropylbenzene, Benzene, Butane, Isobutane, Propylene,
Cyclohexane, 1-Butene and Octene. See Appendix B for instrument display names.

Liquidew EExd User’s Manual
Michell Instruments 3
INTRODUCTION
Four user-programmable tables enable the Liquidew EExd to be applied to virtually any
immiscible solute. For simple mixtures of hydrocarbons, a proportional combination
of the Cs values for two or three individual substances can be applied, although with
increased measurement uncertainty. For applications with complex mixture fluids,
customers can enter their own Cs values (in ppmW for temperatures from 0 to +50°C
(+32 to +122°F)) from their own library sources or from actual laboratory titration
analysis of the fluid concerned.
1.7 Elimination of Temperature Effects
To ensure continuous optimum analysis conditions the Liquidew EExd Main Unit is
temperature controlled (internally) at a stable level. The control temperature level is
selected to suit the climate at the point of installation, being set to the normal maximum
temperature. Such steady state control within the analyzer greatly reduces the effects of
diurnal (day-night) swings in temperature. These temperature changes could otherwise
induce transitional adsorption and desorption effects of the flowing sample and result
in erroneous measurements.
In addition, the Liquidew EExd features an advanced temperature compensation
algorithm that automatically maintains best possible measurement accuracy in the
event of heater failure or if the prevailing climate exceeds the set temperature level.
1.8 Calibration
Maintenance of calibration is essential to the lifetime performance of all analyzers. To
ensure that all customers worldwide can maintain the performance of their Liquidew
EExd, the unique Michell Calibration Exchange Service offers freshly calibrated
replacement Ceramic Sensors certified traceable to NPL and NIST. The calibration
characterization data for each Liquidew EExd Sensor is programmed into on-board
non-volatile memory. Fitting the Calibration Exchange Sensor refreshes the calibration,
returning the measurement performance to day-one. This takes only a few minutes of
downtime while the interchange is made. No programming or data input is required by
the user to complete this.
The calibration exchange is available globally, typically taking less than two weeks, with
comparable cost of a traditional ‘return to manufacturer’ re-calibration service.
The recommended calibration maintenance interval is 12 months.

Liquidew EExd User’s Manual
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INTRODUCTION
1.9 Liquidew EExd Sampling System
(Optional – see separate manual if you have purchased this item)
Figure 1 Liquidew EExd Sampling System
Good sample conditioning and handling is particularly important in the field of moisture
measurement. As the moisture sensor has to be exposed directly to the process liquid
stream in order to detect the dissolved moisture present, key sampling issues such as the
avoidance of particulate contamination are imperative to successful operation. Michell's
30 years of expertise in on-line process moisture analyzers are used to optimize the
design of the Liquidew EExd Sampling Systems. Contact Michell Instruments for further
details: www.michell.com.

Liquidew EExd User’s Manual
Michell Instruments 5
INSTALLATION
2 INSTALLATION
2.1 Electrical Safety
!
WARNING:
During the installation of this product ensure that all
applicable national and local electrical safety regulations
are observed.
WARNING:
Isolate the power prior to installation.
WARNING:
Always ensure that power is switched off prior to accessing
the product for any purpose other than normal operation or
prior to disconnecting any cables.
2.1.1 Equipment Ratings and Installation Details
The mandatory statements contained within refer to the Ex certified Liquidew EExd
Analyzer only (not including the sampling system).
This equipment must be supplied with a voltage between the range of 90 to 260 V AC,
47/63 Hz. Maximum power rating is 180W.
The power is connected via PL1 on the mains connector PCB.
Figure 2 Power Connection Connector
All input and output connectors are 2-part PCB mounted type, rated at 300 V 10 A.
The detachable, screw terminal half of each connector is designed to accept 0.5 to
2.5mm2 [24 -12 AWG] stranded or solid conductors.

Liquidew EExd User’s Manual
697097 Issue 14.1, November 2019
INSTALLATION
Any power connection cable should be 3 core over sleeved, with minimum 0.5mm
insulation and rated at 300 V. Cables should have Live (L), Neutral (N) and Earth
[Ground] (E) conductors. Ensure suitably rated power supply cables and glands are
used to ensure that electrical safety is maintained. Connect each of the Live (L), Neutral
(N) and Earth [Ground] (E) conductors to the similarly marked terminals (L, N, E) on the
Power In connector shown in Figure 3 . Ensure the power supply can deliver sufficient
power consumption requirement.
Any power supply terminals and voltages must be suitably separated from the other I/O
requirements of this product.
Before applying power, perform a continuity test to ensure that the power supply cable
and product are effectively connected to the protective Earth.
The Protective Earth terminal is mounted internally and the Earth wire connected to it
should never be disconnected. The product enclosure is supplied with an external earth
stud at the lower right hand side. At installation, connect this earth stud to plant earth
by a minimum 4mm2 earthing bonding. M6 stud and 2 off M6 nuts and washers, all
nickel plated.
Figure 3 Earthing Stud And Nut Washer Assembly
Fuse: A replacement fuse can be obtained by contacting Michell Instruments' technical
support. Fuse rating = 5 x 20mm 2.5 A anti-surge to IEC 60127-2.
This product is designed to be safe at least under the following conditions: between a
temperature range of -40 to +60°C (-40 to +148°F), in maximum 80% relative humidity
for temperatures up to +31°C (+88°F) decreasing linearly to 50% RH at +50°C
(+122°F). Supply voltages of ±10% and transient over voltages up to Overvoltage
Category II. Pollution Degree 2. Altitudes up to 2000m. Outdoor mounting is permitted
using suitably rated glands equivalent to NEMA 4 / IP66. See Appendix A, Technical
Specification, for full operating parameters.
Do not remove or exchange any of the cables or electrical components supplied with
this product. Doing so will invalidate all warranties.
There are no additional or special electrical safety requirements other than those
referred to in this manual.

Liquidew EExd User’s Manual
Michell Instruments 7
INSTALLATION
Location and mounting arrangements - refer to the relevant sections of this manual for
the location and mounting details.
Installation of this equipment must include the provision of a suitable and locally
positioned power isolation switch or circuit breaker. Indication of the purpose of the
switch or circuit breaker is strongly recommended. An over-current protection device
should be rated to a maximum of 10 A.
This equipment and all power isolation devices must be installed in a location and
position that allows safe and easy access to their operation and is able to rigidly support
the equipment.
Do not install this equipment in a location that would expose it to impact or high levels
of vibration.
Operation of this equipment, other than in a manner specified by the manufacturer, may
impair the safety protections provided.
The safe installation of this equipment and any system incorporating this equipment is
the responsibility of the installer. Ensure local regulations and requirements are referred
to prior to any installation commencing.

Liquidew EExd User’s Manual
897097 Issue 14.1, November 2019
INSTALLATION
2.2 Hazardous Area Safety
Refer to Appendix H for the Hazardous Area Certification of this product.
This product is fitted with a marking label that contains Hazardous Area information
pertinent to the suitable location and installation.
During all installation and operation activities, local regulations and permitted working
routines must be observed. Installation should only be performed by competent personnel
and in accordance with the latest version of IEC/EN60079-14 or local equivalent.
Repair and servicing of this equipment must only be carried out by the manufacturer.
An Installation and Maintenance Information Sheet is supplied separately to the manual.
WARNING:
This product is certified safe for use in a Zone 1 and Zone 2
area only. This product must not be installed or used within
a Zone 0 area.
!
WARNING:
This product must not be operated within an explosive
atmosphere greater than 1.1 bara.
WARNING:
This product must not be operated with enriched oxygen gas
samples (more than 21% oxygen content).
WARNING:
This product must not be operated outside of the
temperature range of -40 to +60°C (-40 to +140°F).
WARNING:
The enclosure of this product provides Exd protection, partly
through the threads used for mounting the lid, stopping
plugs and cable gland. At all times effort should be made to
ensure these threads are suitably protected from damage
and that only appropriately rated mating parts are applied
to them, in accordance with the certifying requirements.

Liquidew EExd User’s Manual
Michell Instruments 9
INSTALLATION
2.3 Pressure Safety
!
WARNING:
This product is used in conjunction with pressurized gases.
Observe pressurized gas handling precautions.
!
WARNING:
Pressurized gas is dangerous.
Pressurized gas should only handled by suitably trained
personnel.
This product requires pressurized gas to be connected to it. Observe pressurized gas
handling regulations. Only suitably trained personnel should carry out tasks that include
the use of pressurized gas mediums.
2.4 Lifting and Handling
!
WARNING:
This instrument is in excess of 18kg (40lbs).
Personnel must observe suitable lifting and handling
precautions.
This product is not designed as portable or transportable equipment. It should be rigidly
fixed in position as per the full installation instructions.
The weight of the analyzer is in excess of 18kg (40lbs). Therefore, appropriate lifting and
handling techniques should be used during the installation process. Before commencing
any lifting or handling ensure that its intended location is suitable and appropriately
prepared. Make sure that mounting point design considerations have employed locally
approved safety factors.
When handling and installing this product (particularly after removal from its packaging)
ensure that it is not dropped, impacted or subjected to high levels of vibration or
environmental conditions that may impair its operation.

Liquidew EExd User’s Manual
10 97097 Issue 14.1, November 2019
INSTALLATION
2.5 Analyzer System
Refer to the Installation & Maintenance Information sheet (supplied separately) and the
System Drawings in Appendix A.
The instrument is housed in an aluminum EExd enclosure suitable for wall or panel
mounting. Four mounting points are available with M12 clearance holes on fixing centres
of X = 270mm x Y = 318mm.
Height: 355mm (13.9”) 500mm (19.68”) including installation clearance
Width: 310mm (12.20”) 500mm (19.68”) including installation clearance
Depth: 245mm (9.64”)
The enclosure provides environmental ingress protection IP66 and should be mounted
vertically in a location free of any appreciable vibration. It should be placed in a shaded
position to prevent heating effects through sun radiation.
The weight of the analyzer is 21kg (46lbs).
270mm 10.63"
318mm 12.52"
355mm [13.9"]
245mm 9.65"
290mm [11.41"]
4 o M12 (1/2")
Clearance
Enclosure Breather
Flame Arrestor
Do NOT obscure
Sample in - Channel 2 (Optional)
Flame Arrestor
1/8" NPT Female (ATEX/IECEx/CSA)
Sample out - Channel 2 (Optional)
Flame Arrestor
1/8" NPT Female (ATEX/IECEx/CSA)
Sample in - Channel 1
Flame Arrestor
1/8" NPT Female (ATEX/IECEx/CSA)
Sample out - Channel 1
Flame Arrestor
1/8" NPT Female (ATEX/IECEx/CSA)
310mm [12.20"]
Cable Entry Glands
3 o M20 (ATEX)
3 o 1/2" NPT (CSA)
Figure 4
Liquidew EExd Dimensions

Liquidew EExd User’s Manual
Michell Instruments 11
INSTALLATION
2.5.1 Pipework
FLOW
METER
CHANNEL 1
FLAME
ARRESTOR
SAMPLING BLOCK
MICHELL MOISTURE
SENSOR
SAMPLE IN SAMPLE OUT SAMPLE IN SAMPLE OUT
MICHELL MOISTURE
SENSOR


FLAME
ARRESTOR
FLAME
ARRESTOR
BREATHER
 
FLAME
ARRESTOR

FLAME
ARRESTOR

FLOW
METER
SAMPLING BLOCK

{
CHANNEL 2
OPTIONAL
{
Figure 5 Pipework Connections
NOTE: Ensure that the process sample gas supply line is well flushed
through to clear any debris present, prior to connection to the instrument.
A sample handling system must prepare the liquid in terms of filtration and
temperature reduction (if greater than +40°C (+104°F) before entering into
the measurement system.
In accordance with the Certification requirements, the Liquidew EExd must have, as a
minimum, those components described in the Sample System Flow Diagram shown in
Figure 6.
The pipework connections are:
Moisture Channel 1 Sample inlet
(Maximum pressure of 80 barg (1160 psig))
1/8" NPT(F)
Moisture Channel 1 Sample outlet
Moisture Channel 2 Sample inlet
(Maximum pressure of 80 barg (1160 psig))
Moisture Channel 2 Sample outlet

Liquidew EExd User’s Manual
12 97097 Issue 14.1, November 2019
INSTALLATION
The following points should be considered when installing the sample liquid supply line:
PTFE tape is recommended for pipe connections. Solvent based pipe thread sealant
should not be used, as condensable components or contaminates can be leached during
the curing period.
It is recommended that Viton is used for all O-rings.
Filtration is critically important to avoid particulate contamination. For process fluids
with high levels of particulates present, two-stage filtration may be required.
For elevated temperature processes, the sample flow temperature should be moderated,
preferably to less than +40°C (+104°F) (max. +60°C (+140°F)), prior to entering the
Liquidew EExd Main Unit.
There should be sufficient differential pressure between sample source and return points
to enable a flow of between 0.1 and 0.3 l/min (0.03 and 0.08 GPM) through the analyzer.
The internal volume of the impulse tubing between the process line and any sampling
system should be as low as possible (sample lines should be kept as short as possible)
to minimize response lag time to changing process conditions.
Piping should be lagged and/or trace heated if ambient temperatures could cause the
sample liquid to fall below its saturation temperature.
It should be standard procedure to isolate the measurement system during shutdowns
or when plant problems are being experienced. The supply lines must be fully purged
before restarting.
2.5.2 Power Connections
A single-phase AC power connection is required.
The power supply can accommodate voltages from 90 to 260 V AC, 47/63 Hz. The unit
requires a maximum of 180W to function correctly.
The connection is made via a two-part connector mounted at the base of the unit. See
Appendix A.
Cable entry into the measurement system is made through the bottom of the enclosure.
• For ATEX/IECEx compliant versions of the product, 3 off ISO M20 tapped
holes are provided.
• For cCSAus compliant version of the product, 3 off ½” NPT entries are
provided.
NOTE: EExd Stopping Glands MUST be used for ATEX/IECEx installations.
Refer to the separate installation & maintenance information sheet supplied.
The terminals are marked:
L = Live
N = Neutral
E = Earth