Vaisala DRYCAP DMT143 User manual

USER'S GUIDE
Vaisala DRYCAP®
Dewpoint Transmitter
DMT143
M211435EN-D

PUBLISHED BY
Vaisala Oyj Phone (int.): [phone]
P.O. Box 26 Fax: [phone]
FI-00421 Helsinki
Finland
Visit our Internet pages at www.vaisala.com.
© Vaisala 2013
No part of this manual may be reproduced, published or publicly displayed in any form
or by any means, electronic or mechanical (including photocopying), nor may its
contents be modified, translated, adapted, sold or disclosed to a third party without prior
written permission of the copyright holder. Translated manuals and translated portions
of multilingual documents are based on the original English versions. In ambiguous
cases, the English versions are applicable, not the translations.
The contents of this manual are subject to change without prior notice.
This manual does not create any legally binding obligations for Vaisala towards
customers or end users. All legally binding obligations and agreements are included
exclusively in the applicable supply contract or the General Conditions of Sale and
General Conditions of Service of Vaisala.

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VAISALA_________________________________________________________________________ 1
Table of Contents
CHAPTER 1
GENERAL INFORMATION............................................................................5
About This Manual...................................................................5
Contents of This Manual .......................................................5
Version Information...............................................................6
Related Manuals ...................................................................6
Documentation Conventions.................................................6
Safety.........................................................................................7
ESD Protection......................................................................7
Recycling .................................................................................. 7
Regulatory Compliances.........................................................8
Trademarks...............................................................................8
License Agreement ..................................................................8
Warranty....................................................................................8
CHAPTER 2
PRODUCT OVERVIEW..................................................................................9
Introduction to DMT143...........................................................9
Basic Features and Options..................................................10
Transmitter Parts....................................................................11
Model with G1/2” ISO228/1 Thread ....................................11
Model with NPT Thread ......................................................12
Loop-Powered Display...........................................................13
Connection Cables.................................................................14
Sampling Accessories...........................................................14
CHAPTER 3
FUNCTIONAL DESCRIPTION.....................................................................15
DRYCAP®Technology...........................................................15
Auto-Calibration ..................................................................15
Sensor Purge ......................................................................15
Sensor Warming in High Humidities ...................................16
DMT143 Startup Sequence....................................................17
Alarm LED...............................................................................18
CHAPTER 4
INSTALLATION............................................................................................19
Transmitter Configuration Before Installation ....................19
Selecting the Location...........................................................20
Installing the Transmitter ......................................................20
Wiring ......................................................................................22
Power Supply Requirements...............................................23
Sampling from a Process......................................................26

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Sampling Accessories ...........................................................26
DMT242SC Sampling Cell ..................................................26
DMT242SC2 Sampling Cell with Swagelok Connectors.....26
DSC74 Sampling Cell with Quick Connector and Leak Screw
.............................................................................................27
DSC74B Two-Pressure Sampling Cell................................28
DSC74C Two-Pressure Sampling Cell with Coil............30
DM240FA Duct Installation Flange ................................32
CHAPTER 5
OPERATION.................................................................................................33
Transmitter Start-Up...............................................................33
Operation with DM70 Hand-Held Dewpoint Meter...............34
Serial Communication............................................................35
Connecting to the Serial Interface.......................................35
Installing the Driver for the USB Service Cable .............35
Terminal Application Settings..............................................36
List of Serial Commands .......................................................38
Device Information .................................................................39
Show Device Information.....................................................39
Show Analog Output Mode .................................................39
Show Firmware Version ......................................................40
Show Firmware Information ................................................40
Show Currently Active Errors..............................................40
Show Serial Number............................................................40
Show Command List ...........................................................41
Configuring Analog Output ...................................................42
Set Analog Output Parameters and Scaling........................42
Set Analog Output Error Notification...................................43
Extend Analog Output Range..............................................44
Test Analog Output..............................................................44
Enable or Disable Analog Output........................................45
Serial Line Output Commands..............................................45
Start Measurement Output..................................................45
Stop Measurement Output ..................................................45
Set Output Interval...............................................................46
Output a Reading Once.......................................................46
Configuring Measurement Parameters ................................47
Set Measurement Output Format........................................47
Set Measured Gas Type......................................................49
Set Measurement Filtering ..................................................49
Set Pressure Compensation Value .....................................50
Select Unit ...........................................................................51
View User Adjustment Parameters .....................................51
Set User Adjustment Parameters........................................52
Configuring Serial Line Operation........................................53
Set Serial Line Operating Mode ..........................................53
Set Serial Line Settings.......................................................54
Set Transmitter Address......................................................54
Set Serial Line Response Time...........................................55
Other Commands....................................................................55
Opening the Transmitter in POLL Mode..............................55
Closing the Connection to a Transmitter in POLL Mode.....55
Configure the Alarm LED.....................................................56
Show Transmitter Uptime....................................................57

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Reset Transmitter................................................................57
Restore Factory Settings.....................................................57
CHAPTER 6
MAINTENANCE ...........................................................................................59
Periodic Maintenance ............................................................59
Cleaning ..............................................................................59
Calibration...........................................................................59
Changing the Filter..............................................................60
Field Check Using the DM70 Hand-Held Dewpoint Meter..61
Repair Maintenance ...............................................................62
CHAPTER 7
TROUBLESHOOTING .................................................................................63
Solving Typical Problems......................................................63
Error Messages ......................................................................64
Unknown Serial Settings.......................................................64
Technical Support..................................................................65
Product Returns .....................................................................65
CHAPTER 8
TECHNICAL DATA......................................................................................67
Specifications.........................................................................67
Spare Parts and Accessories................................................70
Dimensions in mm .................................................................71

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List of Figures
Figure 1 DMT143 Parts – Model with ISO Thread .................................11
Figure 2 DMT143 Parts – Model with NPT Thread ................................12
Figure 3 Nokeval 301 Loop-Powered Display........................................13
Figure 4 DMT143 Startup Sequence......................................................17
Figure 5 Removing the Transport Protection Cap..................................20
Figure 6 Installing the Transmitter with Sealing Ring .............................21
Figure 7 Tightening with a Wrench.........................................................21
Figure 8 DMT143 Digital and Analog Connectors..................................22
Figure 9 Wiring the Digital Connector.....................................................22
Figure 10 Wiring the Analog Connector....................................................22
Figure 11 Example of Current Consumption During Purge......................24
Figure 12 Example of Current Consumption During Auto-Calibration......25
Figure 13 Sampling Cells DMT242SC2 (left) and DMT242SC (right)......27
Figure 14 DSC74 Sampling Cell with Accessories...................................28
Figure 15 DSC74B....................................................................................29
Figure 16 Removing the Leak Screw........................................................29
Figure 17 Default Assembly of DSC74C ..................................................30
Figure 18 Alternative Assembly of DSC74C (for Tight Spaces)...............31
Figure 19 DM240FA with DMT143 ...........................................................32
Figure 20 Measurement Settings Menu....................................................34
Figure 21 PuTTY Terminal Application.....................................................37
Figure 22 Removing the Filter ..................................................................60
Figure 23 Comparing Dewpoint Readings on MI70..................................62
Figure 24 Dewpoint Accuracy vs. Measurement Conditions....................68
Figure 25 DMT143 Dimensions – Model With ISO Thread......................71
Figure 26 DMT143 Dimensions – Model With NPT Thread.....................71
List of Tables
Table 1 Manual Revisions .......................................................................6
Table 2 Related Manuals.........................................................................6
Table 3Output Parameters of the DMT143 ............................................9
Table 4 Alarm LED States.....................................................................18
Table 5 Connector Pinouts....................................................................22
Table 6 Default Serial Interface Settings...............................................36
Table 7 List of Serial Commands ..........................................................38
Table 8 FORM Command Parameters..................................................48
Table 9 FORM Command Modifiers......................................................48
Table 10 Pressure Conversion Coefficients............................................50
Table 11 Selection of Output Modes .......................................................53
Table 12 Troubleshooting Table..............................................................63
Table 13 Error Messages ........................................................................64
Table 14 Measured Parameters..............................................................67
Table 15 Operating Environment.............................................................68
Table 16 Outputs .....................................................................................68
Table 17 General.....................................................................................69
Table 18 Spare Parts and Accessories for DMT143...............................70

Chapter 1 _________________________________________________________ General Information
VAISALA_________________________________________________________________________ 5
CHAPTER 1
GENERAL INFORMATION
This chapter provides general notes for the manual and the DMT143.
About This Manual
This manual provides information for installing, operating, and
maintaining DMT143.
Contents of This Manual
This manual consists of the following chapters:
- Chapter 1, General Information, provides general notes for the manual
and the DMT143.
- Chapter 2, Product Overview, introduces the DMT143 transmitter and
its features.
- Chapter 3, Functional Description, describes the advanced
functionality of DMT143, including the auto-calibration, sensor purge,
and sensor warming functions.
- Chapter 4, Installation, provides you with information that is intended
to help you install the DMT143.
- Chapter 5, Operation, contains information that is needed to operate
the DMT143.
- Chapter 6, Maintenance, provides information that is needed in basic
maintenance of the DMT143.
- Chapter 7, Troubleshooting, describes common problems, their
probable causes and remedies, and provides contact information for
technical support.
- Chapter 8, Technical Data, provides the technical data of the
DMT143.

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Version Information
Table 1 Manual Revisions
Manual Code
Description
M211435EN-D
June 2013. This manual. Updated wiring
instructions.
M211435EN-C
January 2013. Previous version. Updated
command descriptions for ASEL, FORM, SERI, and
SDELAY commands.
M211435EN-B
June 2012. Updated section Alarm LED on page
18. Updated section Configure the Alarm LED on
page 56. Updated technical specification and
dimension drawings.
M211435EN-A
First version.
Related Manuals
Table 2 Related Manuals
Manual Code
Manual Name
M211434EN
DMT143 Quick Guide
M211634EN
Nokeval 301/302 Display Wiring Diagram
Documentation Conventions
Throughout the manual, important safety considerations are highlighted
as follows:
WARNING Warning alerts you to a serious hazard. If you do not read and follow
instructions very carefully at this point, there is a risk of injury or even
death.
CAUTION Caution warns you of a potential hazard. If you do not read and follow
instructions carefully at this point, the product could be damaged or
important data could be lost.
NOTE Note highlights important information on using the product.

Chapter 1 _________________________________________________________ General Information
VAISALA_________________________________________________________________________ 7
Safety
The DMT143 delivered to you has been tested and approved as shipped
from the factory. Note the following precautions:
CAUTION
Do not modify the unit. Improper modification can damage the product
or lead to malfunction.
CAUTION
The transmitter body does not have
user serviceable parts inside, and is
not designed to be opened. Opening the transmitter will void the
warranty.
ESD Protection
Electrostatic Discharge (ESD) can cause immediate or latent damage to
electronic circuits. Vaisala products are adequately protected against
ESD for their intended use. It is possible to damage the product,
however, by delivering electrostatic discharges when touching the
exposed connectors on the back of the product.
To make sure you are not delivering high static voltages yourself, avoid
touching the exposed pins of the connectors.
Recycling
Recycle all applicable material.
Dispose of
the unit according to statutory regulations. Do not dispose of
with regular household refuse.

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Regulatory Compliances
DMT143 is in conformity with the provisions of the following EU
directives:
- EMC-Directive
- RoHS-Directive
Conformity is shown by compliance with the following standards:
- EN 61326-1: Electrical equipment for measurement, control, and
laboratory use – EMC requirements – for use in industrial locations.
- EN 550022: Information technology equipment – Radio disturbance
characteristics – Limits and methods of measurement.
Trademarks
DRYCAP®is a registered trademark of Vaisala Oyj.
All other trademarks are the property of their respective owners.
License Agreement
All rights to any software are held by Vaisala or third parties. The
customer is allowed to use the software only to the extent that is provided
by the applicable supply contract or Software License Agreement.
Warranty
Visit our Internet pages for standard warranty terms and conditions:
www.vaisala.com/warranty.
Please observe that any such warranty may not be valid in case of
damage due to normal wear and tear, exceptional operating conditions,
negligent handling or installation, or unauthorized modifications. Please
see the applicable supply contract or Conditions of Sale for details of the
warranty for each product.

Chapter 2 ___________________________________________________________Product Overview
VAISALA_________________________________________________________________________ 9
CHAPTER 2
PRODUCT OVERVIEW
This chapter introduces the DMT143 transmitter and its features.
Introduction to DMT143
Vaisala DRYCAP®Dewpoint Transmitter DMT143 is a small and
lightweight dewpoint transmitter suitable for a wide range of OEM
applications. The DMT143 is easy to install and the mechanics have been
designed for harsh environments requiring protection against dust, dirt
and splashed water.
DMT143 uses a DRYCAP®polymer sensor for dewpoint measurement.
DRYCAP®technology has low maintenance needs due to its excellent
long term stability and durability against condensation. The calibration
interval of the DMT143 is two years.
Table 3 Output Parameters of the DMT143
Parameter
Abbreviation
Metric Unit
Non-Metric
Unit
Dewpoint/frost point temperature
Tdf
ºC
ºF
Dewpoint/frost point temperature,
converted to atmospheric pressure
Tdfatm
ºC
ºF
ppm moisture, by volume
H20
ppm
ppm
NOTE
When dewpoint is below 0 °C, the transmitter outputs frostpoint for Td.
Dewpoint temperature in atmospheric pressure (Td/f atm) is a calculated
parameter that presents the dewpoint the gas would have at atmospheric
pressure. For this calculation to provide accurate results, it is important to
have the correct pressure setting stored in the transmitter. This setting is
specified on the order form, and it can be changed using the RS-485 line
or DM70 hand-held dewpoint meter.

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Basic Features and Options
- Dewpoint measurement range -60 ... +60 °C (-76 ... +140 °F).
- Dewpoint measurement accuracy up to ±2 °C (±5.4 °F) Td in air or N2.
- Operating pressure range 0 ... 50 bara(725 psia).
- Configurable for optimum dewpoint measurement accuracy:
- Dewpoint measurement in SF6or air.
- Pressure compensation (fixed pressure setting or live pressure
input through RS-485).
- Analog output: one output channel, selectable from:
- 0 ... 1 V
- 0 ... 5 V
- 1 ... 5 V
- 4 ... 20 mA
- Digital output: RS-485 (non-isolated).
- LED for dewpoint level alarm and transmitter diagnostics.
- DRYCAP®polymer sensor:
- Autocalibration ensures accuracy in changing measurement
conditions.
- Sensor warming keeps the sensor dry in high humidity.
- Sensor purge ensures long term stability.
- NIST traceable (certificate included).
- Field check suitability with DM70 hand-held dewpoint meter.
- Optional accessories:
- Stainless steel grid filter for vacuum applications.
- Sampling cells with various installation options.
- Loop-powered external display.
- Connection cable for DM70 hand-held dewpoint meter.
- Plastic shipping case for avoiding contamination during
shipping.

Chapter 2 ___________________________________________________________Product Overview
VAISALA________________________________________________________________________ 11
Transmitter Parts
NOTE
When the transmitter is delivered, the filter is protected by a yellow
transport protection cap that keeps the sensor dry. The transport
protection cap should be left on the transmitter during storage. Remove
the transport protection cap before
installing the transmitter.
Model with G1/2” ISO228/1 Thread
1202-120
Figure 1 DMT143 Parts – Model with ISO Thread
The following numbers refer to Figure 1 above:
1
=
Transmitter body. Type label is applied here.
2
=
Digital output: non-isolated RS-485.
3
=
Alarm LED.
4
=
Analog output.
5
=
Sealing ring.
Must be used with the G1/2” ISO228/1 connection thread.
6
=
24 mm nut.
7
=
Connection thread: G1/2" ISO228/1.
8
=
DRYCAP®sensor protected with sintered filter.

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Model with NPT Thread
1202-121
Figure 2 DMT143 Parts – Model with NPT Thread
The following numbers refer to Figure 1 on page 11:
1
=
Transmitter body. Type label is applied here.
2
=
Digital output: non-isolated RS-485.
3
=
Alarm LED.
4
=
Analog output.
5
=
30 mm nut.
6
=
Connection thread: NPT 1/2".
7
=
DRYCAP®sensor protected with sintered filter.

Chapter 2 ___________________________________________________________Product Overview
VAISALA________________________________________________________________________ 13
Loop-Powered Display
DMT143 can be connected to a loop-powered external LED display. The
display provides a reading of the output parameter. The display is
powered by the 4 ... 20 mA current signal, so there is no need for an
external power supply.
Two models are available:
- Nokeval 301
- Nokeval 302 (with alarm relays)
The display is delivered at its default settings. Configure the display
functions and scaling according to the documentation delivered with the
display. For a wiring example, see Nokeval 301/302 Display Wiring
Diagram (document code M211634EN). For the order codes of the
displays, see section Spare Parts and Accessories on page 70.
1102-053
Figure 3 Nokeval 301 Loop-Powered Display
NOTE
The loop resistance of the display must be included in the loop resistance
calculation for the
complete current loop. For the loop resistance of the
display, refer to the manufacturer’s documentation.

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Connection Cables
Vaisala supplies shielded cables with M8 female straight threaded
connector. Standard cables are available in four lengths:
- 0.3 m (1.0 ft)
- 3 m (9.8 ft)
- 5 m (16.4 ft)
- 10 m (32.8 ft)
Heavy duty cables are available in two lengths:
- 1.5 m (4.9 ft)
- 3 m (9.8 ft)
Also available are the following cables for service and field check use:
- USB service cable
- MI70 connection cable
For the order codes of the cables, see section Spare Parts and Accessories
on page 70.
Sampling Accessories
DMT143 is compatible with various sampling accessories. For more
information on performing sampling, and a description of the accessories,
see section Sampling Accessories on page 26.
For the order codes of the sampling accessories, refer to section Spare
Parts and Accessories on page 70.

Chapter 3 _______________________________________________________ Functional Description
VAISALA________________________________________________________________________ 15
CHAPTER 3
FUNCTIONAL DESCRIPTION
This chapter describes the advanced functionality of DMT143, including
the auto-calibration, sensor purge, and sensor warming functions.
DRYCAP®Technology
Vaisala DRYCAP®dewpoint measurement technology ensures accurate
measurement with excellent long term stability. This results in very low
maintenance requirements for the transmitter. The lasting performance is
achieved with microprocessor technology and software that automatically
performs self-diagnostic functions in addition to the normal dewpoint
measurement. The self-diagnostic procedures that are conducted are
called auto-calibration, sensor purge, and sensor warming.
Auto-Calibration
The auto-calibration feature of the DMT143 transmitter is an automatic
procedure which greatly reduces the possible drift in the dry end of the
dewpoint measurement. It is performed at one hour intervals, and when
the power is switched on. During auto-calibration the sensor is warmed
for a short period (< 1 min) and the sensor capacitance values are
evaluated at the elevated temperature. The possible dry end drift is then
corrected to correspond to the calibrated values. During the auto-
calibration the transmitter outputs the Tdvalue prior to the procedure.
Auto-calibration is carried out only if several criteria for the
measurement environment are fulfilled. This ensures the reliability of the
adjustments, and maintains the excellent long term stability that the
patented technology offers. These criteria include for example a stable
enough moisture level in the measured atmosphere. If the conditions are
not fulfilled, the auto-calibration function is postponed until satisfactory
conditions are reached.
Sensor Purge
Sensor purge is also an automatic procedure that minimizes the drift at
the wet end readings of the dewpoint measurement. Sensor purge is
performed once a day or when the power is switched on. The sensor is
heated for several minutes which will then evaporate all excess

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molecules out of the sensor polymer. This, together with the auto-
calibration results in a very small drift of the sensor due to the very linear
behaviour of the polymer technology. During the sensor purge the
transmitter outputs the Tdvalue prior to the procedure.
Sensor Warming in High Humidities
DMT143 has a warming feature which maintains the sensor temperature
above 0 °C, and prevents the sensor and filter from becoming wet in high
humidities. High humidity may be present when the dewpoint
temperature rises close to the gas temperature.
Sensor warming is switched on automatically when the humidity in the
measured gas increases to a level where dew can start to form. The
advantage of sensor warming is the rapid response of dewpoint
measurement. A wet sensor and filter would otherwise result in a
dewpoint equal to ambient temperature (that is RH = 100 %).
If in spite of sensor warming the sensor gets soaked, it will recover fully
back to normal operation after it dries out.

Chapter 3 _______________________________________________________ Functional Description
VAISALA________________________________________________________________________ 17
DMT143 Startup Sequence
When the transmitter is powered up, it will perform the sequence shown
in Figure 4 below. After a two-second startup, the transmitter will
measure normally for five minutes, after which it will perform the sensor
purge and auto-calibration functions. This can take up to six minutes,
during which time the output is frozen: it will display the last measured
values before the sensor purge began.
The auto-calibration function may be postponed if the measurement
environment is not suitable. For example, the environment may be
changing rapidly or have too high humidity.
Normal operation and output is typically achieved no later than 11
minutes after startup. The sensor purge will repeat every 24 hours, and
auto-calibration every hour. The output will again be frozen for their
duration.
1202-115
Figure 4 DMT143 Startup Sequence
NOTE
The transmitter always performs this sequence when starting up. Keep
the transmitter continuously powered to optimize its measurement
performance and availability.
Normal output Normal output
2 s
Output frozen
5 min 3 ... 6 min
Time
Purge*
3 ... 4 min Autocal** <2 min
* Purge will repeat every 24 hours
** Autocal will repeat every 60 minutes (is postponed if environment is not suitable)
Startup

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Alarm LED
The alarm LED at the back of the transmitter provides a visual indication
of the transmitter’s status. The alarm LED functionality is preset at the
factory according to order form. You can configure it as follows:
- You can change the alarm limit using the DM70 hand-held dewpoint
meter. See section Operation with DM70 Hand-Held on page 34.
- You can use the ALARM command on the serial line to change the
alarm limit, enable/disable the dewpoint alarm, or turn on/off the LED
completely. See section Configure the Alarm LED on page 56.
Table 4 Alarm LED States
LED Color
Meaning
Not lit
Power off or LED functionality disabled.
Green
Power on, normal measurement.
Green and blinking
Purge or autocalibration in progress, measurement
frozen.
Red
Dewpoint above limit.
Red and blinking
Transmitter error. See section Error Messages on
page 64.