Easidew
Dew-Point Transmitter
User’s Manual
97504 Issue 3.1
May 2019
Please ll out the form(s) below for each instrument that has been purchased.
Use this information when contacting Michell Instruments for service purposes.
Transmitter
Code
Serial Number
Invoice Date
Location of Instrument
Tag No
Transmitter
Code
Serial Number
Invoice Date
Location of Instrument
Tag No
Transmitter
Code
Serial Number
Invoice Date
Location of Instrument
Tag No
Easidew
For Michell Instruments' contact information please go to
www.michell.com
© 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.
Easidew Transmitter User’s Manual
Contents
Safety .......................................................................................................................................v
Electrical Safety .................................................................................................................. v
Pressure Safety ..................................................................................................................v
Toxic Materials .................................................................................................................... v
Repair and Maintenance ......................................................................................................v
Calibration ..........................................................................................................................v
Safety Conformity ............................................................................................................... v
Abbreviations ............................................................................................................................ vi
Warnings .................................................................................................................................. vi
1 INTRODUCTION .......................................................................................................... 1
2 INSTALLATION ............................................................................................................. 2
2.1 Unpacking the Instrument ......................................................................................... 2
2.2 Preparation of the Sensor Cable ................................................................................. 3
2.3 Cable Connection ......................................................................................................4
2.4 Electrical Schematic ..................................................................................................5
2.4.1 Electrical Boundaries ...........................................................................................6
2.4.2 Digital Communication (M12 Version only) ............................................................6
2.5 Transmitter Installation .............................................................................................6
2.5.1 Sampling Considerations ......................................................................................6
2.5.2 Sampling Hints ...................................................................................................8
2.5.3 Transmitter Mounting ........................................................................................ 11
2.5.3.1 5/8” 18 UNF Version ................................................................................... 11
2.5.3.2 3/4” - 16 UNF Version ................................................................................. 12
2.5.3.3 G1/2" BSPP Version .................................................................................... 12
2.5.3.4 Installation using Additional Thread Adaptor ................................................. 12
3 MAINTENANCE .......................................................................................................... 14
Figures
Figure 1 DIN43650 Transmitter Unpacking Method ......................................................... 2
Figure 2 Connector Terminal Block Removal ................................................................... 3
Figure 3 Wiring Connections ......................................................................................... 3
Figure 4 Connector Installation...................................................................................... 4
Figure 5 Connector Installation...................................................................................... 5
Figure 6 2-Wire Connection Diagram ............................................................................. 5
Figure 7 Maximum Load of Easidew - Including Cable Resistance .................................... 6
Figure 8 Installation Location ........................................................................................ 7
Figure 9 Transmitter Mounting - Sensor Block ................................................................. 8
Figure 10 Material Permeability Comparison ..................................................................... 9
Figure 11 Dead volume ................................................................................................ 10
Figure 12 Transmitter Mounting - Pipe or Duct ............................................................... 11
Figure 13 Transmitter Mounting with Adapter ................................................................ 13
Figure 14 Replacement of HDPE Guard .......................................................................... 14
Figure 15 Dimensions - Easidew ................................................................................... 17
Appendices
Appendix A Technical Specications ...................................................................................17
Appendix B Quality, Recycling & Warranty Information ........................................................20
Appendix C Return Document & Decontamination Declaration ..............................................22
Appendix D Modbus Register Map ......................................................................................24
iv 97504 Issue 3.1, May 2019
Easidew Transmitter 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.
Pressure Safety
DO NOT permit pressures greater than the safe working pressure to be applied to the instrument.
The specied safe working pressure is 45 MPa (450 barg / 6500 psig). Refer to the Technical
Specications 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 be maintained either by the manufacturer or an accredited service agent. For
Michell Instruments’ contact information please go to www.michell.com.
Calibration
The recommended calibration interval for this instrument is 12 months unless it is to be used in a
mission-critical application or in a dirty or contaminated environment in which case the calibration
interval should be reduced accordingly. 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 and US standards
and directives. Further details of applied standards may be found in the Technical Specications in
Appendix A.
Michell Instruments v
Abbreviations
The following abbreviations are used in this manual:
barg pressure unit (=100 kP or 0.987 atm) gauge
ºC degrees Celsius
ºF degrees Fahrenheit
DC direct current
ft-lbs foot-pound force
g grams
in inch(es)
µm micrometer
m/sec meters per second
mA milliampere
max maximum
mm millimetres
MPa megapascal
Nl/min normal liters per minute
Nm Newton meter
oz ounces
ppm
V
psig pounds per square inch
RH relative humidity
scfh standard cubic feet per hour
scfs standard cubic feet per second
T temperature
V Volts
Ω Ohms
ø diameter
Easidew Transmitter User’s Manual
parts per million by volume
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.
vi 97504 Issue 3.1, May 2019
Easidew Transmitter User’s Manual
1 INTRODUCTION
The Michell Instruments Easidew is a 4-20mA loop-powered dew-point transmitter,
designed to make dew point measurements in a owing sample. The Easidew transmitter
is available with 3 dierent process connections:
• 5/8" - 18 UNF : Easidew 2-wire, Easidew M12
• 3/4" - 16 UNF : Easidew 34, Easidew M12
• G1/2 : Easidew M12
The Easidew 2-wire is available with a choice of electrical connections:
• DIN 43650 Form C
• M12 5-Pin
INTRODUCTION
Michell Instruments 1
INSTALLATION
87653 421
2 INSTALLATION
2.1 Unpacking the Instrument
On delivery, please check that all the following standard components are in the packing
tube:
• Easidew Transmitter
• Certicate of Calibration
• Connector (for sensor/cable)
The Transmitter will also be supplied with a process seal, which will be tted to the
unit. Depending on the version, this will either be a bonded seal (5/8" or G1/2" thread
versions) or an o-ring seal (3/4" thread versions).
Unpack the dew-point transmitter tube as follows:
Easidew Transmitter User’s Manual
Figure 1
1. Unscrew the cap (1) from the packing tube (8).
2. Remove the foam block (3) containing the connector (2).
3. Pull out the transmitter (5) from the tube, complete with the two foam
covers (6) and (7) and the red protective cap (4).
4. Remove the foam covers from the transmitter but leave the blue plastic
protective cover (5) and the red cap (4) in place until ready for installation.
NOTE: The transmitter sensing element is protected while in transit by a blue
cover containing a small desiccant capsule. The connection pins are protected
by a red plastic cap. None of these plastic items are required for the operation
of the transmitter.
NOTE: Keep the connector (2) in a safe place until the transmitter is ready
for wiring.
DIN43650 Transmitter Unpacking Method
2 97504 Issue 3.1, May 2019
Easidew Transmitter User’s Manual
2.2 Preparation of the Sensor Cable
The sensor cable is NOT supplied as standard. Cables can be obtained by contacting your
local Michell Instruments representative (see www.michell.com for details).
DIN 43650 Version
Cable connection to the Easidew transmitter is made via the removable connector. Removing
the central screw enables the connector terminal block to be removed from the outer
housing by using a small screwdriver to prise it clear.
O-ring
and washer
INSTALLATION
Figure 2
Connector Terminal Block Removal
Caution: When removing the central screw ensure that the
small sealing O-ring and the washer are retained on the screw
and are present during re-installation.
The sensor cables are terminated as per the following diagram:
BRAID
SCALE 2:1
SHORT
AS POSSIBLE
+POWER
GREEN
SIGNAL (SOURCE)
1
3
RED
2
VIEW ON REAR
OF CONNECTOR
BLUE
GND
4
Figure 3
BRAID
SCREEN
GREEN
YELLOW
BLUE
RED
Wiring Connections
GN
RD
BL
GREEN 4-20 mA
RED + POWER
BLUE - GND / SCREEN
GREEN 4-20 mA
(SOURCE)
BLUE - GND / SCREEN
RED + POWER
Note: The screen should only be connected to a ground point at either the
transmitter installation side, or at the receiving equipment. Failure to observe
this precaution can result in ground loops and equipment malfunction.
Michell Instruments 3
INSTALLATION
M12 5-Pin Version
Cables with moulded M12 connectors are available from Michell Instruments in the
following lengths:
• 0.8m
• 2m
• 5m
Easidew Transmitter User’s Manual
Always connect the 4-20 mA return signal to a suitable load
(see
Figure 3)
connection, the transmitter may be damaged if allowed to
PIN 1 Modbus B
PIN 2 Modbus A
PIN 3 4-20 mA
PIN 4 Power supply
PIN 5 0V
before the power is applied. Without this
operate for prolonged periods.
4-20 mA 2-wire
M12 5-WAY
A CODED
12
5
3 4
Figure 4
The other end of the sensor cable is unterminated, for straightforward connection into
the desired monitoring system.
CABLE ASSEMBLY CONNECTIONS
FUNCTION PIN WIRE COLOUR
MODBUS B 1 BROWN
MODBUS A 2 WHITE
4 - 20 mA 3 BLUE
POWER SUPPLY 4 BLACK
Ov 5 GREY
Sensor Connector Installation
Figure 5
If longer cable runs are required, o-the-shelf 5-pin M12 cables can be connected
between the Easidew transmitter and the cable provided by Michell Instruments.
Note: The screen should only be connected to a ground point at either the
transmitter installation side, or at the receiving equipment. Failure to observe
this precaution can result in ground loops and equipment malfunction.
Cable connections
4 97504 Issue 3.1, May 2019
Easidew Transmitter User’s Manual
2.3 Cable Connection
DIN 43650 Version
To ensure the specied ingress protection is achieved, when installing the connector, the
securing screw (with the O-ring and washer) must be tightened to a minimum torque of 3.4
Nm (2.5 ft-lbs). The sensor cable used must be a minimum diameter of 4.6mm (0.2”).
INSTALLATION
O-ring
and washer
M12 5-Pin Version
The connector should be installed by aligning the locating pin on the transmitter with
the slot on the cable. The connector can then be pushed into place and rotated until
nger-tight.
2.4 Electrical Schematic
Note: The screen should only be connected to a ground point at either the
transmitter installation side, or at the receiving equipment. Failure to observe
this precaution can result in ground loops and equipment malfunction.
3
1
Figure 6
Connector Installation
Screen/
Shield
Max Load
200R @ 12V
500R @ 24V
+
Supply
12V Min
28V Max
Figure 7
2-Wire Connection Diagram
Michell Instruments 5
INSTALLATION
2.4.1 Electrical Boundaries
600
500
400
300
Resistance (ohms)
200
Easidew Transmitter User’s Manual
100
12 14 16 18 20 22 24 26 28
Supply Voltage
Figure 8
2.4.2 Digital Communication (M12 Version only)
Modbus RTU over RS485 communication is available on the Easidew M12, and can be
used simultaneously with the 2-wire current output. Section 2.2 describes the electrical
connections to the transmitter.
The Modbus register map can be found at the end of this manual.
2.5 Transmitter Installation
Maximum Load of Easidew - Including Cable Resistance
2.5.1 Sampling Considerations
There are two basic methods of measuring a sample with the Easidew Transmitter:
In-situ measurements are made by placing the transmitter inside the environment to
be measured.
Extractive measurements are made by installing the sensor into a block within a sample
handling system, and owing the sample outside of the environment to be measured
through this system.
Extractive measurements are recommended when the conditions in the environment
to be measured are not conducive to making reliable measurements with the product.
6 97504 Issue 3.1, May 2019
Easidew Transmitter User’s Manual
Examples of such conditional limitations are:
• Excessive ow rate
• Presence of particulates matter
• Presence of entrained liquids
• Excessive sample temperature
The basic considerations for each measurement type are as follows:
In-Situ
1. Dew-Point Sensor Position – will the sensor see an area of the
environment that is representative of what you want to measure?
For example, if the sensor is to be mounted into a glove box, there are three dierent
positions in which it could be installed – each giving a dierent measurement:
• Position A is on the purge inlet. In this position the sensor will conrm the
dew point of the gas entering the glove box, but will not detect any leaks
in the glove box itself, or any moisture released from the work piece.
INSTALLATION
• Position B is on the gas outlet. In this position the sensor will be exposed
to the gas leaving the glove box, and will therefore be detecting any
moisture which has entered into the system (e.g. ingress/leaks), or has
been released by the work piece.
• Position C is in the glovebox itself, in this position the sensor will be
only detecting any moisture in its immediate vicinity. Leaks not in close
proximity to the measurement point may not be detected as this moisture
could be drawn directly to the outlet.
A
1 2
B
C
1. Purge Inlet
2. Gas Outlet
Figure 9
If the transmitter is to be mounted directly into a pipe or duct, then consider that the
installation point should not be too close to the bottom of a bend where oil or other
condensate may collect.
Installation Location
Michell Instruments 7
INSTALLATION
Easidew Transmitter User’s Manual
Figure 10
2. Gas speed – if you are planning on installing the sensor in a duct, consider
how fast the sample gas is moving through it.
If the gas speed is very low, or occasionally static, then the moisture content through
the length (and width, if it is more than a few cm across) of the duct is unlikely to be
uniform.
Extremely high gas speeds can cause damage to the sensor. Direct insertion is not
recommended in gas speeds in excess of 10m/s (32.8ft/s).
3. Particulates – Particulates travelling at speed can cause severe and
irreversible damage to the sensor. At low velocity they can cling to the sensor,
reducing its’ surface area, and therefore response speed.
The sensor is provided with a basic level of particulate protection in the form of a
sintered guard; either HDPE (10μm pore size) or Stainless Steel (80μm pore size). If
the sample stream contains smaller particulates than this, or generally large amounts
of dust; extractive measurement is recommended to accommodate proper in-line
ltration.
Installation Location
4. Sample Temperature – Although the Easidew can be operated at sample
temperatures up to 70°C, it is advisable to keep the sample temperature as
close to ambient, and as stable as possible to keep adsorption & desorption
characteristics as consistent as possible (see section X.X Sampling Hints for
more information).
Extractive
If the sensor is to be mounted into a sample conditioning system, then the above points are
still of relevance, but it is important to consider the extraction point itself – make sure that
the chosen extraction point is representative of the process, i.e. that the sample of interest
is owing past the extraction point, and it is not being pulled from a dead volume.
8 97504 Issue 3.1, May 2019
Easidew Transmitter User’s Manual
2
INSTALLATION
1
2.5.2 Sampling Hints
Measurement of moisture content is a complex subject, but does not need to be dicult.
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.
2a
Figure 11
4
3
Transmitter Mounting - Sensor Block
Figure 12
All materials are permeable to water vapour, as the water molecule is extremely small
compared to the structure of solids, even when compared to the crystalline structure of
metals. The graph above shows the dew point inside tubing of dierent 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 vapour pressure exerted on the outside of a compressed air line is
higher than on the inside, the atmospheric water vapour will naturally push through the
Material Permeability Comparison
Michell Instruments 9
INSTALLATION
porous medium causing water to migrate into the pressurised air line. This eect 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 lm. 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 indenitely. However, as the temperature rises, so does the likelihood of desorption
occurring.
In practical terms, as the temperature of the environment uctuates, water molecules are
adsorbed and desorbed from the internal surfaces of the sample tubing, causing small
uctuations in the measured dew point.
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.
Easidew Transmitter User’s Manual
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.
Figure 13
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.
Dead volume
10 97504 Issue 3.1, May 2019
Easidew Transmitter User’s Manual
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 analyser completely when a large slug of liquid is encountered.
Condensation and Leaks
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 vapour 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
vapour pressure differential will also allow water vapour to contaminate the flow.
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.
INSTALLATION
An inadequate ow rate can:
• Accentuate adsorption and desorption eects 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 ow.
• Increase the chance of contamination from back diusion: ambient air that
is wetter than the sample can ow from the exhaust back into the system.
A longer exhaust (sometimes called a pigtail) can also help alleviate this
problem.
• Slow the response of the sensor to changes in moisture content.
2.5.3 Transmitter Mounting
Once an installation location has been chosen, this point will require a thread to match
the transmitter thread. Fixing dimensions are shown in Figure 6. For circular pipework,
to ensure the integrity of a gas tight seal, a mounting ange will be required on the
pipework in order to provide a at surface to seal against.
Michell Instruments 11
INSTALLATION
Easidew Transmitter User’s Manual
1
2
3
1
2
Figure 14
2.5.3.1 5/8” 18 UNF Version
1. Remove the protective cover and desiccant capsule from the transmitter and
retain for future use
2. Prevent any contamination of the sensor before installation by handling the
transmitter by the main body only, avoiding contact with the sensor guard.
3. Pass the bonded seal over the 5/8”- 18 UNF mounting thread.
4. Screw the transmitter into the sampling location or sample block by hand
using the wrench flats only. DO NOT grip and twist the sensor cover
when installing the sensor.
5. When installed, fully tighten using a wrench to a torque setting of 30.5 Nm
(22.5 ft-lbs)
48mm
3
Transmitter Mounting - Pipe or Duct
12 97504 Issue 3.1, May 2019
Easidew Transmitter User’s Manual
2.5.3.2 3/4” - 16 UNF Version
1. Remove the protective cover and desiccant capsule from the transmitter and
retain for future use.
2. Prevent any contamination of the sensor before installation by handling the
transmitter by the main body only, avoiding contact with the sensor guard.
3. Ensure that the O-ring is seated in the recess at the top of the transmitter
body.
4. Screw the transmitter into the sampling location or sample block by hand
using the wrench flats only. DO NOT grip and twist the sensor cover
when installing the sensor.
5. When installed, fully tighten using a wrench to a torque setting of 40 Nm
(29.5 ft-lbs).
2.5.3.3 G1/2" BSPP Version
INSTALLATION
1. Remove the protective cover and desiccant capsule from the transmitter
and retain for future use
2. Prevent any contamination of the sensor before installation by handling
the transmitter by the main body only, avoiding contact with the sensor
guard.
3. Pass the bonded seal over the G1/2" mounting thread.
4. Screw the transmitter into the sampling location or sample block by hand
using the wrench flats only. DO NOT grip and twist the sensor cover
when installing the sensor.
5. When installed, fully tighten using a wrench to a torque setting of 30.5
Nm (22.5 ft-lbs)
2.5.3.4 Installation using Additional Thread Adaptor
1. Remove the protective cover and desiccant capsule from the transmitter and
retain for future use
2. Prevent any contamination of the sensor before installation by handling the
transmitter by the main body only, avoiding contact with the sensor guard.
3. Pass the bonded seal over the 5/8”- 18 UNF mounting thread.
4. Screw the transmitter into the adaptor, and tighten to 30.5 Nm (22.5 ft-lbs)
5. NOTE: Use the flats of the hexagonal nut and not the sensor body.
6. Screw the transmitter (1) with its seal (3) and adapter (4) into the sampling
location block (and fully tighten using a wrench to the following torque settings:
• G 1/2” BSP 56 Nm (41.3 ft-lbs)
• 3/4” - 16 UNF ` 40 Nm (29.5 ft-lbs)
• 1/2” NPT Use a suitable sealant e.g. PTFE tape using correct taping
procedures
Michell Instruments 13
INSTALLATION
2
r
Easidew Transmitter User’s Manual
2a
4
1
Figure 15
Calibration
Annual recalibration of the Easidew is recommended to maintain the performance.
Calibration services traceable to the UK
US
National Institute of Standards and Technology
Instruments.
Transmitter Mounting with Adapter
National Physical Laboratory
3
MAINTENANCE
(NPL) and the
(NIST) are provided by Michell
Michell Instruments oers a variety of re-calibration and exchange sensor schemes to
suit specic needs. A Michell representative can provide detailed, custom advice (for
Michell Instruments’ contact information go to www.michell.com).
Sensor Guard Replacement
The sensor is supplied with a white HDPE guard (standard) or a stainless steel guard (if
specied at time or order).
The sensor guard should be replaced if the surface shows any damage or signs of
discolouration. When replacing a guard, make sure to wear clkean disposable gloves,
and handle by the threaded base section only.
Replacement HDPE or stainless steel guards can be ordered from your Michell Instruments
representative.
HANDLE,
USING
GLOVES, BY
BLACK PART
ON LY
E
n
e
H
m
C
u
I
r
6
t
s
0
M
n
9
I
0
Figure 16
Replacement of HDPE Guard
14 97504 Issue 3.1, May 2019
Easidew Transmitter User’s Manual
Bonded Seal
If the supplied bonded seal is damaged or lost, a pack of 5 replacement bonded seals
can be obtained by your Michell Instruments representative.
O-ring Seal
If the supplied O-ring seal is damaged or lost a pack of 5 replacement O-ring seals
can be obtained by contacting your Michell Instruments representative.
INSTALLATION
Michell Instruments 15
APPENDIX A
Easidew Transmitter User’s Manual
Appendix A
Technical Specications
16 97504 Issue 3.1, May 2019
Easidew Transmitter User’s Manual
APPENDIX A
Appendix A Technical Specications
Product Easidew, Easidew M12 and Easidew 34
Transmitter
Performance Specications
Measurement range –110 to +20°C dew point; –100 to +20°C dew point; non standard ranges available on request
Accuracy ±2°C dew point*
Response time 5 mins to T95 (dry to wet)
Repeatability 0.5°C dew point
Calibration Traceable 13 point calibration certicate
Electrical Specications
Output signal
Output Dew point or moisture content
Analog output scaled range Dew point: –110 up to +20°C; Moisture content in gas: 0– up to 3000 ppm
Supply voltage 12 to 28 V DC
Load resistance Max 250 Ω @ 14 V (500 Ω @ 24 V)
Current consumption 23 mA max, depending on output signal
CE conformity 2014/30/EU
UL approval Approved
UL61010-1 & CAN/CSA C22.2 No. 61010-1
4–20 mA (2-wire connection, current source); User congurable over range
Easidew M12: Modbus RTU over RS485
Operating Specications
Operating temperature –40 to +60°C
Compensated temperature range -20 to +50°C
Storage Temperature -40 to +60°C
Operating pressure 45 MPa (450 barg) maximum
Flow rate 1 to 5 Nl/min mounted in standard sampling block; 0 to 10 m/sec direct insertion
Mechanical Specications
Ingress protection
Intrinsically safe area certicates
Oxigen service Optional: cleaned for enriched oxygen service
Housing material 316 stainless steel
Dimensions
Filter (sensor protection)
Process connection
Weight 150g
Electrical connections
Mating Electrical Connectors
Diagnostic conditions
(factory programmed)
Approved galvanic isolators
IP66 in accordance with standard BS EN 60529:1992; NEMA 4 protection in accordance
MiniDIN 43650 form C L=132mm x ø45mm (with connector cable)
Easidew M12: M12 5 pin L = 155mm x ø45mm (with connector cable)
Optional: 316 stainless steel sintered guard <80µm
Easidew M12: 5/8” -18 UNF, 3/4” - 16 UNF, G1/2” BSP
Easidew M12: optional 0.8, 2, 5 metre M12 A coded connector/cable available
with standard NEMA 250–2003
Easidew M12: IP65
ATEX: II 1 G Ex ia IIC T4 Ga (-20 to +70 °C)
IECEx: EX ia IIC T4 Ga (-20 to +70 °C)
TC TR@ 0Ex ia IICT4 Ga (-20 to +70 °C)
FM: Class I, Division 1, Groups A B C D, T4
CSAUS: Class I, Division 1, Groups A B C D, T4
C
Standard: HDPE <10µm
Easidew: 5/8” - 18 UNF
Easidew: G1/2" BSPP
Easidew 34: 3/4” - 16 UNF
Easidew: MiniDIN 43650 form C
Easidew M12: M12 5 Pin (A coded)
Mating connector supplied as standard
Conditions
Sensor fault
Under-range dew point
Over-range dew point
Output
23 mA
4 mA
20 mA
KFD2-CR-EX1.20200
KFD2-CR-EX1.30200
KFD0-CS-EX1.50P
KFD0-CS-EX2.50P
KFD2-STC4-EX1.H
MTL5041
MTL5040
Easidew I.S. Transmitter
V;
NOTES * Over Compensated Temperature Range
Michell Instruments 17
APPENDIX A
1/8” NPT
13.0 0.512
46.0 1.811
60.3 2.374
12.7 0.500
8.0 0.315
27.0 1.063
O
5/8" UNF THREAD
BONDED SEAL
M12 5-WAY
A CODED
27.0 1.063 A/F
DIMENSIONS IN mm [INCHES]
13.0 0.512
46.0 1.811 60.3 2.374 12.7 0.500
8.0 0.315
27.0 1.063
O
G1/2 THREAD
BONDED SEAL
M12 5-WAY
A CODED
27.0 1.063 A/F
DIMENSIONS IN mm [INCHES]
13.0 0.512
44.0 1.732 62.3 2.453 12.7 0.500
10.0 0.394
27.0 1.063
O
3/4" UNF THREAD
O-RING SEAL
M12 5-WAY
A CODED
27.0 1.063 A/F
DIMENSIONS IN mm [INCHES]
Dimensions
Product Dimensions
Easidew Easidew M12
10mm
(0.39”)
132mm
(5.19”)
ø27mm
(1.06”)
10mm
(0.39”)
46mm
(1.81”)
5/8” UNF
5/8” Bonded Seal
ø25.4 x 2mm
(ø1 x 0.07”)
27mm
(1.06”)
A/F
Easidew Transmitter User’s Manual
45mm
(1.77”)
46mm
(1.81”)
G1/2” BSP
46mm
(1.81”)
3/4” UNF
G1/2” BSP Bonded Seal
ø28.65 x 2.61mm
(ø1.12 x 0.10”)
3/4” O-Ring
ø18.72 x 2.62mm
(ø0.75 x 0.09”)
Figure 6
27mm
(1.06”)
A/F
27mm
(1.06”)
A/F
45mm
(1.77”)
45mm
(1.77”)
27 A/F
1/8” NPT
(see accessories and spare parts)
55.2mm
Optional Sample Block
Dimensions - Easidew
ø30mm
30mm
5/8”-18 UNF
3/4” UNF
G1/2” BSP
5/8”-18 UNF
3/4” UNF
G1/2” BSP
10mm
(0.39”)
10mm
(0.39”)
132mm
(5.19”)
ø27mm
(1.06”)
132mm
(5.19”)
ø27mm
(1.06”)
10mm
(0.39”)
10mm
(0.39”)
18 97504 Issue 3.1, May 2019
Easidew Transmitter User’s Manual
APPENDIX B
Appendix B
Quality, Recycling
& Warranty
Information
Michell Instruments 19
APPENDIX B
Easidew Transmitter User’s Manual
Appendix B 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
• Conict 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.
20 97504 Issue 3.1, May 2019
Easidew Transmitter User’s Manual
APPENDIX C
Appendix C
Return Document &
Decontamination Declaration
Michell Instruments 21
APPENDIX C
Easidew Transmitter User’s Manual
Appendix C Return Document & Decontamination Declaration
Decontamination Certicate
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
materials. For most applications involving solvents, acidic, basic, ammable or toxic gases a simple purge with dry
gas (dew point <-30°C) over 24 hours should be sufcient to decontaminate the unit prior to return.
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
22 97504 Issue 3.1, May 2019
Easidew Transmitter User’s Manual
APPENDIX D
Appendix D
Modbus Register Map
Michell Instruments 23
APPENDIX D
Appendix D Modbus Register Map
All the data values relating to the Easidew are stored in 16-bit wide holding registers.
Registers can contain either measured or calculated values (dew-point, temperature,
etc.), or conguration data (output settings).
Modbus RTU Implementation
This is a partial implementation of the Modbus RTU Standard with the following codes
implemented:
Function Code Description
3 Read Holding Register
6 Write Holding Register
16 Write Multiple Holding Registers
Register Types
Easidew Transmitter User’s Manual
Data Type Description
uint16
int16 16 bit signed integer.
int32 32 bit signed integer, stored across 2 16 bit registers.
special Refer to register description/comments for data structure.
Serial Port Settings (RS485)
9600 Baud Rate, 8 Data Bits, No Parity, 1 Stop Bit, No Flow Control
http://www.simplymodbus.ca/FAQ.htm is an excellent resource
covering the basics of the Modbus protocol. Full descriptions
of the function codes (FC03/FC06/FC16) can be found in the
sidebar.
16 bit unsigned integer, can contain options list e.g. 0 = Dew
Point, 1 = Temperature.
https://www.scadacore.com/tools/programming-calculators/
online-hex-converter/ is an excellent resource for determining
register types/byte order issues in raw received Modbus data.
24 97504 Issue 3.1, May 2019
Easidew Transmitter User’s Manual
Register Address
APPENDIX D
Dec Hex Access Data
Type
0 0000 R/W uint16 Instrument Modbus Address 1-255
3 0003 R special Status/Fault Indication
bit0, Sensor short circuit
bit1, Sensor open circuit
bit2, Thermistor short circuit
bit3, Thermistor open circuit
bit4, Sensor over range
bit5, Sensor under range
bit6, Thermistor over range
bit7, Thermistor under range
4 0004 R/W special Output Configuration
Sensor fault output
bit0, 4mA
bit1, 20mA
bit2, 23mA
bit3, 3mA
Dew-point under-range
output
bit4, 4mA
bit5, 20mA
bit6, 23mA
bit7, 3mA
Dew-point over-range output
bit8, 4mA
bit9, 20mA
bit10, 23mA
bit11, 3mA
Output parameter
bit12, Temperature
bit13, ppmV
bit14, ppmW
bit15, Natural gas
8 0008 R special Transmitter Firmware Version 0x0100 = 1.0
10 000A R/W int16 Measurement Range Low 10x multiplier, i.e. -1000 =
11 000B R/W int16 Measurement Range High 10x multiplier, i.e. 200 = 20.0
15 000F R special Sensor Batch Number Batch 0xA123
16 0010 R special Sensor Serial Number
17 0011 R/W special Year of Calibration 0x2018 = 2018
18 0012 R/W special Month & Day of Calibration 0x317 = March 17th
54 0036 R/W int16 Pressure value for ppmV
(barg)
Description Comment
Only one bit can be set for
each parameter, for example
‘sensor fault’ can be EITHER
4mA OR 20mA OR 23mA OR
3mA.
If bits 13 – 16 are not set, then
the output will be dew point.
Natural gas parameter set in
register 78.
-100.0
Serial 0x0001
Complete sensor serial would
be A123-001
10x multiplier, i.e. 100 = 10.0
Michell Instruments 25
APPENDIX D
Easidew Transmitter User’s Manual
78 004E R/W special Natural Gas Configuration &
Precision Select
Register conguration in 1 decimal place precision mode
Dec Hex Access Data
Type
1 0001 R int16 Humidity Parameter Default dew-point, selected
2 0002 R int16 Ambient Temperature 10x multiplier, i.e. 214 = 21.4
Register configuration in 4 decimal place precision mode
Description Comment
Natural gas configuration
bit1, 0=IGT, 1=ISO
bit2, lb/MMscf
bit3, ppmV NG
bit4, mg/m3 NG
Precision Select
bit15, 0=1 Decimal Place,
1=4 Decimal Places
with register 4 (and 78 for
Natural gas)
10x multiplier, i.e. -811 = -81.1
Dec Hex Access Data
Type
1 0001 R special Humidity Parameter (Low
Word)
2 0002 R special Humidity Parameter (High
Word)
7 0007 R int16 Ambient Temperature 10x multiplier, i.e. 214 = 21.4
Description Comment
Default dew-point, selected
with register 4 (and 78 for
Natural gas)
1000x multiplier,
i.e. 14321 = 1.4321
26 97504 Issue 3.1, May 2019
Easidew Transmitter User’s Manual
NOTES:
Michell Instruments 27
http://www.michell.com
Loading...