Vaisala DRYCAP DMT152 User Manual

Download

M210865EN-J

User Guide

Vaisala DRYCAPâ Dew Point Transmitter

DMT152

PUBLISHED BY

Vaisala Oyj Vanha Nurmijärventie 21, FI-01670 Vantaa, Finland P.O. Box 26, FI-00421 Helsinki, Finland +358 9 8949 1

Visit our Internet pages at www.vaisala.com.

No part of this document 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 documents 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 document are subject to change without prior notice.

Local rules and regulations may vary and they shall take precedence over the

information contained in this document. Vaisala makes no representations on this document’s compliance with the local rules and regulations applicable at any given time, and hereby disclaims any and all responsibilities related thereto.

This document 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.

Table of Contents

1. About This Document................................................................................... 7

1.1 Version Information..........................................................................................7

1.2 Related Manuals................................................................................................ 7

1.3 Documentation Conventions...........................................................................7

1.4 Trademarks........................................................................................................ 8

2. Product Overview...........................................................................................9

2.1 Introduction to DMT152....................................................................................9

2.1.1 Basic Features and Options......................................................................9

2.1.2 Transmitter Structure.............................................................................. 10

2.1.3 Safety..........................................................................................................11

2.1.4 ESD Protection...........................................................................................11

2.1.5 Regulatory Compliances.......................................................................... 11

3. Functional Description................................................................................ 12

3.1 Advanced DRYCAP Technology.................................................................... 12

3.1.1 Auto-Calibration.......................................................................................12

3.1.2 Sensor Purge.............................................................................................12

4. Installation........................................................................................................ 13

4.1 Selecting the Location....................................................................................13

4.2 Installing the Transmitter................................................................................13

4.3 Wiring................................................................................................................15

4.3.1 Output Noise Minimization Option........................................................ 17

4.3.2 Connection Cables................................................................................... 18

4.3.3 Power Supply Requirements.................................................................. 19

4.4 Loop-Powered Display................................................................................... 19

4.5 Sampling from Process..................................................................................20

4.6 Sampling Accessories..................................................................................... 21

4.6.1 DMT242SC Sampling Cell........................................................................21

4.6.2 DMT242SC2 Sampling Cell with Swagelok Connectors...................... 21

4.6.3 DSC74 Sampling Cell with Quick Connector and Leak Screw........... 22

4.6.4 DSC74B Two-Pressure Sampling Cell................................................... 23

4.6.5 DSC74C Two-Pressure Sampling Cell with Coil...................................25

4.6.6 NW40 Mounting Flange......................................................................... 28

5. Serial Line Operation.................................................................................. 29

5.1 Connecting to Serial Interface......................................................................29

5.1.1 Installing Driver for USB Service Cable................................................ 29

5.1.2 Terminal Application Settings............................................................... 29

5.1.3 List of Serial Commands..........................................................................31

5.2 Device Information.........................................................................................33

5.2.1 Show Device Information.......................................................................33

5.2.2 Show Transmitter Status........................................................................ 33

5.2.3 Show Firmware Version..........................................................................34

DMT152 User Guide M210865EN-J

5.3 Conﬁguring Analog Outputs.........................................................................35

5.3.1 Limit Alarm.............................................................................................. 36

5.3.2 Purge Status Alarm................................................................................. 37

5.3.3 Malfunction Alarm...................................................................................38

5.3.4 Select Analog Output Parameter and Scaling.....................................39

5.4 Conﬁguring Serial Line Operation................................................................39

5.4.1 Set Serial Line Settings...........................................................................39

5.4.2 Set Serial Line Response Time.............................................................. 40

5.4.3 Set Transmitter Address........................................................................ 40

5.4.4 Set Measurement Output Format.........................................................40

5.4.5 Select Unit................................................................................................42

5.4.6 Set Serial Line Operating Mode.............................................................43

5.5 Conﬁguring Measurement Parameters........................................................43

5.5.1 Enable or Disable Sensor Purge............................................................ 43

5.5.2 Set Pressure Value for ppm Calculation...............................................44

5.5.3 Set Molar Mass for ppmw Calculation...................................................45

5.6 Serial Line Output Commands..................................................................... 46

5.6.1 Start Measurement Output....................................................................46

5.6.2 Stop Measurement Output.....................................................................47

5.6.3 Set Output Interval..................................................................................47

5.6.4 Output a Reading Once..........................................................................47

5.7 Troubleshooting and Maintenance Commands..........................................48

5.7.1 Display Currently Active Errors.............................................................48

5.7.2 Test Analog Outputs...............................................................................48

5.7.3 Calibrate Analog Output........................................................................49

5.7.4 Extend Analog Output Range...............................................................49

5.8 Other Commands...........................................................................................50

5.8.1 Opening the Transmitter in POLL Mode...............................................50

5.8.2 Closing the Connection to a Transmitter in POLL Mode....................50

5.8.3 Display Command List.............................................................................51

5.8.4 Set Time.....................................................................................................51

5.8.5 Reset Transmitter..................................................................................... 51

5.8.6 Set LED Voltage........................................................................................51

5.8.7 Restore Factory Settings........................................................................52

6. Maintenance....................................................................................................53

6.1 Cleaning the Transmitter............................................................................... 53

6.2 Changing the Filter.........................................................................................53

6.3 Calibration and Adjustment..........................................................................54

6.3.1 Field Check Using DM70........................................................................ 54

7. Troubleshooting............................................................................................ 57

7.1 Typical Problems.............................................................................................57

7.2 Unknown Serial Settings................................................................................57

7.3 Error State........................................................................................................57

7.4 Error Codes..................................................................................................... 58

Table of Contents

8. Technical Data............................................................................................... 60

8.1 Speciﬁcations................................................................................................. 60

8.2 Spare Parts and Accessories.........................................................................63

8.3 Dimensions......................................................................................................65

Warranty............................................................................................................ 67

Technical Support............................................................................................67

Recycling...........................................................................................................67

DMT152 User Guide M210865EN-J

List of Figures

Figure 1 DMT152 Probe Parts.........................................................................................10

Figure 2 DMT152 Installed Directly to Pipeline (Max. 50 bar)............................... 13

Figure 3 Connectors I and II............................................................................................16

Figure 4 Connector Pinout..............................................................................................16

Figure 5 Output Noise Minimization Wiring Option................................................ 17

Figure 6 Nokeval 301 Loop-Powered Display...........................................................20

Figure 7 DMT152 Nokeval 301/302 Wiring Diagram...............................................20

Figure 8 Sampling Cells DMT242SC2 (Left) and DMT242SC (Right).................22

Figure 9 DSC74 Sampling Cell with Accessories......................................................23

Figure 10 DSC74B............................................................................................................... 24

Figure 11 Removing the Leak Screw............................................................................. 25

Figure 12 Default Assembly of DSC74C....................................................................... 26

Figure 13 Alternative Assembly of DSC74C (for Tight Spaces).............................27

Figure 14 NW40 Mounting Flange.................................................................................28

Figure 15 NW40 Mounting Flange Dimensions......................................................... 28

Figure 16 Filter Structure..................................................................................................53

Figure 17 Accuracy Over Temperature Range.............................................................61

Figure 18 DMT152 Dimensions........................................................................................ 65

List of Tables

Table 1 Document Versions (English).......................................................................... 7

Table 2 Related Manuals...................................................................................................7

Table 3 DMT152 Measurement Parameters.................................................................9

Table 4 Standard Wiring Pinouts and Wire Colors..................................................15

Table 5 Output Noise Minimization Wiring Option Pinouts and

Wire Colors..........................................................................................................17

Table 6 Connection Cable Options.............................................................................. 18

Table 7 Default Serial Interface Settings...................................................................29

Table 8 List of Serial Commands.................................................................................. 31

Table 9 ? command......................................................................................................... 33

Table 10 STAT command................................................................................................. 34

Table 11 VERS command................................................................................................ 34

Table 12 AMODE command............................................................................................ 35

Table 13 ALARM command.............................................................................................36

Table 14 STATUS command............................................................................................ 38

Table 15 AERR command................................................................................................ 38

Table 16 ASEL command.................................................................................................39

Table 17 SERI command.................................................................................................. 39

Table 18 FORM Command Parameters.........................................................................41

Table 19 FORM Command Modiﬁers.............................................................................41

Table 20 UNIT command..................................................................................................42

Table 21 SMODE Command............................................................................................43

Table 22 Selection of Output Modes............................................................................ 43

Table 23 XPUR command................................................................................................44

Table 24 PRES and XPRES command..........................................................................44

Table 25 Pressure Conversion Coecients.................................................................45

Table 26 MOL command.................................................................................................. 46

Table 27 R Command........................................................................................................46

Table 28 INTV Command................................................................................................. 47

Table 29 ERRS command................................................................................................ 48

Table 30 ATEST command.............................................................................................. 48

Table 31 ACAL command................................................................................................49

Table 32 AOVER command.............................................................................................49

Table 33 OPEN command................................................................................................50

Table 34 CLOSE command..............................................................................................50

Table 35 TIME command...................................................................................................51

Table 36 LED command....................................................................................................52

Table 37 Error Codes.........................................................................................................58

Table 38 Measurement Performance........................................................................... 60

Table 39 Operating Environment................................................................................... 61

Table 40 Inputs and Outputs........................................................................................... 61

Table 41 Mechanical Speciﬁcations.............................................................................. 62

Table 42 Output Cable Speciﬁcations.......................................................................... 62

Table 43 Accessories.........................................................................................................63

List of Tables

DMT152 User Guide M210865EN-J

Chapter 1 – About This Document

1. About This Document

1.1 Version Information

Table 1 Document Versions (English)

Document Code Date Description

M210865EN-J October 2019 This manual.

• Added information on Nokeval display support.

• Corrected the dew point measurement range upper limit specification from −10 °C to −20 °C.

• Added information on the minimum valid pressure setting in the PRES/XPRES

• Updated the document template.

M210865EN-H October 2017 Previous version. IP class speciﬁcation of the probe

M210865EN-G October 2015 Updated the dew point temperature measurement

updated to IP66 (applies to probes manufactured from March 2017 onwards). Added information about the output noise minimization wiring option.

accuracy

speciﬁcation.

1.2 Related Manuals

commands.

Table 2 Related Manuals

Document Code Description

M210866EN DMT152 Quick Reference Guide

1.3

Documentation Conventions

WARNING!

follow instructions carefully at this point, there is a risk of injury or even death.

CAUTION!

follow instructions carefully at this point, the product could be damaged or important data could be lost.

Warning alerts y

Caution w

ou to a serious hazard. If you do not read and

arns you of a potential hazard. If you do not read and

DMT152 User Guide M210865EN-J

Note highlights important information on using the product.

1.4 Trademarks

DRYCAPâ is a registered trademark of Vaisala Oyj.

All other product or company names that may be mentioned in this publication are trade names, trademarks, or registered trademarks of their respective owners.

Chapter 2 – Product Overview

2. Product Overview

2.1 Introduction to DMT152

The Vaisala DRYCAPâ dew point transmitter DMT152 measures dew point temperature accurately in a measurement range from −80 °C to −20 °C (−112 … −4 °F). The maximum output range of the transmitter is −100 … 20 °C (−148 … +68 °F).

DMT152 is designed for a wide range of OEM applications. The transmitter is easy to install, and the mechanics have been designed for harsh environments requiring protection against dust, dirt, and splashed water.

The excellent stability and reliability of the transmitter’s performance is based on advanced DRYCAP polymer sensor technology. The DRYCAP technology has low maintenance needs due to its excellent long-term stability and durability against condensation. For more information on DRYCAP technology, see Advanced DRYCAP Technology (page 12).

DMT152 Measurement Parameters

Table 3 DMT152 Measurement Parameters

Parameter Abbreviation Metric Unit Non-Metric Unit

Dew point / frost point temperature

Parts per million H2O ppmv/ppm

TDF °C °F

ppmv/ppm

2.1.1 Basic Features and Options

• Calibrated dew point measurement range −80 … −20 °C Td, output range

−100 … +20 °C T

• Output in Td 1) and ppm

• DRYCAP polymer sensor with auto-calibration and sensor purge ensures long-term stability

• Small size to ﬁt in tight installations

• Two analog output channels, selectable from 0 … 20 mA / 4 … 20 mA and 0 … 5 V / 0 … 10 V

• Conﬁgurable alarm modes for analog outputs

• Digital output: RS-485

• Serial line connection also via USB serial interface cable

• Simultaneous use of analog and digital output possible

• Field check suitability with DM70 handheld meter

• Sampling cells with dierent installation options available as optional accessories

1) When the dew point is below 0 °C, the transmitter outputs frost point for T

DMT152 User Guide M210865EN-J

• LED cable option that enables a visual indication of transmitter status: LED lit when measurement is frozen (for example, purge active), blinking for malfunction alarm

2.1.2 Transmitter Structure

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.

The transmitter body does not have user serviceable parts inside, and is not designed to be opened. Opening the transmitter will void the warranty.

Figure 1 DMT152 Probe Parts

4-pin M8 connector I: analog output channels and operating power

1 2 4-pin M8 connector II (shown with protective cap): digital output (RS-485) and operating

power

3 Tightening nut (30 mm) 4 Connection thread, alternatives:

• ISO G1/2"

• NPT 1/2"

• UNF 3/4"-16 2A

5 DRYCAP sensor protected with stainless steel mesh ﬁlter (see Changing the Filter

When installing a DMT152 transmitter with ISO or UNF thread, use a sealing ring to achieve a tight installation. Three copper sealing rings are provided with the transmitter, and more can be ordered from Vaisala. Note that the sealing rings for ISO and UNF threads are dierent. See

Spare Parts and Accessories (page 63).

• UNF 5/8"-18

(page 53))

Chapter 2 – Product Overview

Do not use a sealing ring with the NPT thread. Instead, seal the thread using PTFE tape or PTFE sealant paste.

2.1.3 Safety

This product has been tested for safety. Note the following precautions:

CAUTION!

product or lead to malfunction.

CAUTION!

and is not designed to be opened. Opening the transmitter will void the warranty.

Do not modify the unit. Improper modiﬁcation can damage the

The transmitter body does not have user serviceable parts inside,

2.1.4 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. However, it is possible to damage the product by delivering an electrostatic discharge when touching, removing or inserting any objects inside the equipment housing.

Avoid touching component contacts or connectors when working with the device.

2.1.5 Regulatory Compliances

This product 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

DMT152 User Guide M210865EN-J

3. Functional Description

3.1 Advanced DRYCAP Technology

Dew point transmitter DMT152 utilizes an advanced, patented measurement technology to ensure 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 dew point measurement. The self-diagnostic procedures that are conducted are called auto-calibration, sensor purge, and sensor warming.

3.1.1 Auto-Calibration

The auto-calibration feature of the DMT152 transmitter is an automatic procedure that greatly reduces the possible drift in the dry end of the dew point measurement.

Auto-calibration is performed:

• at 45-minute intervals

• at shorter intervals if Td is near the dry end of the measurement range

• when the transmitter is powered up

• when the measured environment changes rapidly.

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. Measurement and output remain active during auto-calibration.

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.

3.1.2 Sensor Purge

Sensor purge is also an automatic procedure that minimizes the drift at the wet end readings of the dew point measurement. Sensor purge is performed once a week or when the power is switched on. The sensor is heated for several minutes, which will then evaporate all excess molecules out of the sensor polymer. This, together with the auto-calibration, results in a very small drift. The measurement output of the transmitter is frozen to the last measured value for the duration of the sensor purge.

Chapter 4 – Installation

4. Installation

4.1 Selecting the Location

It is important that the conditions at the point of installation represent well the gas to be measured. Temperature changes do not aect the dew point measurement, but pressure changes will have an eect on the measurement. All leaks in the system must be eliminated to avoid ambient humidity aecting the measurement.

Direct installation to the measured gas is the recommended installation method if the temperature of the gas is suitable for DMT152 and no additional ﬁltering is needed due to very dusty or oily gas. Oil as such is not harmful for the DRYCAP sensor, but response time may be slower if there are oil particles in the system, or if oil is collected to the ﬁlter over a longer period of time. The maximum measurement pressure is 50 bara / 725 psia (absolute pressure)

for direct measurement.

If the gas temperature is higher than the speciﬁed maximum operating temperature of the transmitter, gas sampling and cooling it to ambient temperature (for example, 10 °C / 18 °F) is recommended. Note that the dew point temperature must be clearly lower than the ambient temperature to avoid condensation in the sampling line. Sampling from the process is easy by using Vaisala sampling cell options; see Sampling Accessories (page 21).

DMT152 is light in weight, which means that it can be installed in a sample pipeline in the sampling cells without the need for any additional mechanical support.

4.2

Installing the Transmitter

Figure 2 DMT152 Installed Directly to Pipeline (Max. 50 bar)

30 mm

DMT152 User Guide M210865EN-J

After selecting a suitable measurement location, install the transmitter as instructed here.

1. Remove the yellow transport protection cap from the transmitter. Do not touch the ﬁlter with your hands.

2. Prepare the sealing of the connection:

a. If the transmitter has a parallel ISO G1/2" thread or UNF 3/4"-16 thread, place the

sealing ring at the base of the thread. Always use a new sealing ring; do not reuse a previously installed one.

b. If the transmitter has an NPT 1/2" thread, do not use the sealing ring. Instead, apply

PTFE tape or suitable sealant paste to the thread. Follow the application instructions of the paste.

3. Make sure that the threads on the mounting point are of the correct type, and fasten the transmitter to the measurement point. Use your hands to turn the probe until it feels tight. Do not use force at this point, and check that the sealing ring (if used) remains centered.

4. Use a 30 mm wrench to tighten the connection to 25 Nm. If you do not have a 30 mm wrench, use a 1 3/16" wrench or an adjustable wrench.

CAUTION!

NOT apply force to other points in the probe body.

Only tighten the probe from the 30 mm tightening nut. Do

Chapter 4 – Installation

5. Connect the wires of the connection cable. When using cables provided with DMT152, see

Wiring (page 15) and Power Supply Requirements (page 19).

6. Plug in the cable to the transmitter. Be sure to use the correct connector; see Wiring

(page 15).

7. Cover the unused connector on the transmitter with the rubber plug that is attached to the transmitter.

8. Turn on the power supply. DMT152 performs self-diagnostics at startup, and the output is frozen for several minutes. The transmitter will output an approximated reading after one minute, but accurate measurement will only be available after the startup procedure is complete.

Normal operation is typically achieved in 10 … 15 minutes. If the measurement environment changes during the startup, the startup may take up to 15 minutes.

The transmitter always performs the self-diagnostic procedure and sensor purge when starting up. Keep the transmitter continuously powered to optimize its measurement performance and availability.

4.3 Wiring

Table 4 Standard Wiring Pinouts and Wire Colors

Pin Connector I Connector II Wire Color

1 VDC supply+ VDC supply+ Brown

2 Signal Ch 1+ RS-485 - / B White

3 GND GND Blue

4 Signal Ch 2+ / LED RS-485 + / A Black

342

V/m A

+ / A

RS485

- / B

DMT152 User Guide M210865EN-J

Figure 3 Connectors I and II

Figure 4 Connector Pinout

CAUTION!

one of them, but do not connect more than one supply voltage in permanent installations. Temporary simultaneous use with the USB serial interface cable or DM70 handheld dew point meter (which also provide operation power) is OK.

The power supply lines are internally connected. You can use either

4.3.1 Output Noise Minimization Option

342

V/m A

+ / A

RS485

- / B

To minimize the output noise:

• Wire only the analog outputs (V/mA) to Port I

• Connect the power supply only to Port II

Avoid connecting the Port I and Port II grounds (pin #3) together

Chapter 4 – Installation

Figure 5 Output Noise Minimization Wiring Option

The wiring of pinouts 1 … 4 in ports I and II in the output minimization option is described in the following table.

Table 5 Output Noise Minimization Wiring Option Pinouts and Wire Colors

Pin Connector I Connector II Wire Color

1 Not wired VDC supply+ Brown

2 Signal Ch 1+ RS-485 - / B White

3 GND GND Blue

4 Signal Ch 2+ / LED RS-485 + / A Black

DMT152 User Guide M210865EN-J

4.3.2 Connection Cables

The following connection cable options are available for DMT152:

• Unshielded cable with M8 female straight snap-on connector

• Shielded cable with M8 female straight threaded connector

• Unshielded cable with LED indicator for analog channel 2, 90° angled M8 female threaded connector

• USB serial interface cable

For cable order codes, see Spare Parts and Accessories (page 63).

Avoid using long cables (over 2 m) with voltage output.

Table 6 Connection Cable Options

DMT152 Connection Cable Options

Cable with Snap-On Connector Cable with Threaded Connector

LED Cable USB Serial Interface Cable

Chapter 4 – Installation

4.3.3 Power Supply Requirements

The DMT152 transmitters are designed to operate with a supply voltage of 15 … 28 VDC (voltage output version) or 21 … 28 VDC (current output version). When only the RS-485 output is used, 11 … 28 VDC is enough in typical measurement conditions.

When measuring in pressures 20 … 50 bara (290 … 725 psia) or in temperatures −40 … 0 °C (−40 … 32 °F), a supply voltage of 21 … 28 VDC is required.

The power supply should maintain the voltage for all load conditions. Voltage ﬂuctuations must be smaller than 0.3 V, as continuous supply voltage ﬂuctuation may interfere with the auto-calibration function.

• If auto-calibration has failed due to voltage ﬂuctuation, you can verify it using the STAT command on the serial line. See Show Transmitter Status (page 33).

• If auto-calibration fails repeatedly, the Autocal error code will be activated. See Error

Codes (page 58).

Current consumption during normal operation is 20 mA. Consumption increases during autocalibration and sensor purge. The maximum current consumption is 220 mA pulsed current.

DMT152 can be powered by the MI70 indicator or the Vaisala USB cable. However, the power supplied by these devices may not be enough for all functions of the transmitter (for example, the current output). If you are using a separate power supply in connector I, connect the power supply ﬁrst before connecting the USB cable or the MI70 indicator. The order is important, since the transmitter will use the power supply that is connected ﬁrst.

4.4 Loop-Powered Display

DMT152 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 (Vaisala order code 226476)

• Nokeval 302 (with alarm relays, Vaisala order code 234759)

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 Figure 7

(page 20) .

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.

134

DMT152 Analog connector 4 ... 20 mA output

4 Ch2+ (black)

2 Ch1+ (white)

3 GND (blue)

1 VDC+ (brown)

Power supply 21 ... 28 VDC

301/302Nokeval

mA+

mA-

301/302Nokeval

mA+

mA-

DMT152 User Guide M210865EN-J

Figure 6 Nokeval 301 Loop-Powered Display

Figure 7 DMT152 Nokeval 301/302 Wiring Diagram

4.5

Sampling is needed when direct measurement of the air or gas is not possible or desirable. This may be related to, for example, a high process temperature, protecting the sensor from water spikes, the need to easily detach the instrument from a pressurized process without running the whole process down, or wanting to make the measurement at a more convenient location. To get a representative sample of the process gas and avoid error sources caused by the sampling system, the following aspects should be considered:

Sampling from Process

Chapter 4 – Installation

Pressure

It is important to keep in mind that changing the pressure of a gas changes the dew point temperature of the gas. If the sensor is at a dierent pressure than the process itself, there may be an error of several tens of degrees in the dew point measurement. You can use the Vaisala Humidity Calculator to simulate the eect of pressure change to dew point. The Humidity Calculator can be found at www.vaisala.com/humiditycalculator.

Leak Tightness and Materials

Due to the typically very low level of humidity, dew point measurements are sensitive to ambient moisture leaks. It is therefore important to have a leak tight sampling system construction.

The system is likewise sensitive to diusion of water molecules through the materials, as well as the absorption of moisture into the materials. The piping should preferably be made of metal, for example, stainless steel with a good surface ﬁnish. Hygroscopic materials such as plastics are undesirable and should be avoided.

Sample tubing should be as short in length as possible. "Dead ends" should be avoided. Also minimizing the number of connections helps in avoiding leaks. If possible, prepare for measurements by ﬂushing the sampling lines with dry gas.

Flow

Vaisala DRYCAP sensor is not ﬂow-dependent as such. For this reason, the ﬂow of the system is not critical to the measurement, although a higher ﬂow improves the response time.

Typically, a ﬂow of 1 ... 2 l/min (0.035 ... 0.7 ft3/min) is enough.

4.6

Sampling Accessories

4.6.1 DMT242SC Sampling Cell

The DMT242SC is a basic sampling cell with only the main sampling cell body. The inlet and outlet are female threaded sample connectors (inlet G3/8", outlet G1/4" ISO).

The DMT242SC is suitable for users requiring only a sampling cell to ﬁt the transmitter into and doing further assembly (piping into inlet and outlet, valves, possible ﬂow meter) by themselves.

4.6.2 DMT242SC2 Sampling Cell with Swagelok Connectors

The DMT242SC2 is similar to DMT242SC, but connections are made easy. The sampling cell includes welded Swagelok connectors at both the inlet and outlet that ﬁt directly to 1/4" tubing.

To ﬁt 6 mm tubing to the connectors, an adapter such as Swagelokâ Reducer SS-6M0-R-4 (not supplied by Vaisala) can be used.

DMT152 User Guide M210865EN-J

DMT242SC2 is the suitable choice in, for example, plastics drying systems, where the measurement is made by tapping o the dryer system and bringing a small air stream to the sensor.

The Swagelok connectors of DMT242SC2 connect easily to a cooling coil or tubing, providing the essential function of cooling the dry air to ambient temperature before it reaches the sensor.

Figure 8 Sampling Cells DMT242SC2 (Left) and DMT242SC (Right)

Male pipe welded connector Swagelok 1/4"

1 2 G1/2" 3 G1/4" 4 G3/8"

4.6.3 DSC74 Sampling Cell with Quick Connector and Leak Screw

The DSC74 has been designed especially for compressed air lines. The sampling cell contains an adjustable leak screw that allows keeping up the pipeline pressure at the sensor. The leak screw is opened and closed with a screwdriver. The leak screw should be 1/2 turn open. This can be veriﬁed by ﬁrst closing the leak screw, then turning 1/2 turn to open it. Then the air coming out will make a barely audible little hiss and it can be lightly felt when putting a hand in front of the air stream.

Chapter 4 – Installation

Do not open the leak screw more than 1/2 turn to avoid reducing the pressure in the sampling cell.

The DSC74 comes with a quick connector that ﬁts to industry standard compressed air line connectors (suitable for type D, Quick08, NIP08). This allows for easy installation and detachment of the dew point transmitter without having to shut down the process. Alternative ways to connect are through the two dierent thread adapters (G3/8" to G1/2" and G3/8" to G1/4" ISO) that are supplied with each DSC74 unit.

When using the DSC74, seal the threads of the quick connector or thread adapter carefully with PTFE thread seal tape. Tighten with an open-end wrench.

Figure 9 DSC74 Sampling Cell with Accessories

Thread adapter type G3/8" - G1/2"

1 2 Thread adapter type G3/8" - G1/4" 3 Quick connector 4 Leak screw 5 Sampling cell body (DMT242SC)

4.6.4 DSC74B Two-Pressure Sampling Cell

The DSC74B and DSC74C sampling cells are enhanced versions of the DSC74. The body is designed in a way that it is possible to measure at both system pressure and atmospheric pressure.

DMT152 User Guide M210865EN-J

The DSC74B limits the ﬂow rate with a ﬁxed leak screw. The ﬂow is optimized for pressures 3 ... 10 barg. The ﬁxed leak screw eliminates the risk of opening the leak screw fully by accident and this way emptying a gas vessel. The maximum ﬂow can be increased, if needed, by removing the leak screw and adjusting the ﬂow manually with the valve. Harmful gases can be recovered by connecting a collection system at the outlet (not available from Vaisala).

In the basic operation of the DSC74B, the gas ﬂows to the sensor from the front and the outlet is on the side. To have the measurement done at atmospheric pressure, the inlet and outlet are reversed. Then the reducing parts supplied (G3/8" - G1/2" or G3/8" - G1/4") on the outlet side help to protect the sensor from ambient humidity coming in.

DSC74B parts are:

• Sampling cell, thread G3/8"

• Connection part with a needle valve and an integrated leak screw

• Reducing Nipple (thread adapter), G3/8" - G1/2"

• Reducing Adapter (thread adapter), G3/8" - G1/4"

Figure 10 DSC74B

1 2 Gas comes out

Gas goes in

Chapter 4 – Installation

Figure 11 Removing the Leak Screw

4.6.5 DSC74C Two-Pressure Sampling Cell with Coil

The DSC74C with an outlet coil is designed for the most critical measurements at atmospheric pressure. In the DSC74C, the coil is connected to the sampling cell outlet to protect the sensor from ambient humidity disturbing the measurement. The coil can also be used as a cooling coil for sampling from high temperature processes.

DSC74C parts are:

• Sampling cell, thread G3/8"

• Connection part with a needle valve and an integrated leak screw

• Reducing nipple (thread adapter), G3/8" - G1/2"

• Reducing adapter (thread adapter), G3/8" - G1/4"

• Diusion coil (for measurements in atmospheric pressure)

DMT152 User Guide M210865EN-J

Figure 12 Default Assembly of DSC74C

Gas goes in. The coil can also be used here.

1 2 Gas comes out 3 Coil 4 Valve

Chapter 4 – Installation

Figure 13 Alternative Assembly of DSC74C (for Tight Spaces)

Gas comes out

1 2 Coil 3 Thread, max. size 7 mm 4 Gas goes in 5 Valve

The thread size cannot exceed 7 mm. Use the provided adapter to avoid damage to the transmitter.

30 [1.18]

17.8 [0.70]

41.2 [1.62]

53 [2.09]

55 [2.17]

1 [0.04]

3.5 [0.14]

13 [0.51]

G1/2 ISO228

14 [0.55]

33 [1.30]

21 [0.83]

mm [in]

DMT152 User Guide M210865EN-J

4.6.6 NW40 Mounting Flange

An NW40 mounting ﬂange (Vaisala order code 225220SP) is available for installations through thin chamber walls or into vacuum processes. The ﬂange is compatible with ISO G1/2" threaded transmitters.

Vaisala does not provide the ﬂange counterpart, only the attachment for DMT152.

Figure 14 NW40 Mounting Flange

Figure 15 NW40 Mounting Flange Dimensions

Chapter 5 – Serial Line Operation

5. Serial Line Operation

5.1 Connecting to Serial Interface

DMT152 can be connected to a PC using the RS-485 line on Port II. You can use, for example, the USB serial interface cable (Vaisala order code 219690). The cable also provides enough operating power for transmitter conﬁguration purposes from the USB port. For continuous measurement, it is recommended to supply the transmitter with operating power from another cable: see Power Supply Requirements (page 19).

If you have not used the DMT152 USB serial interface cable before, install the driver that came with the cable. See Installing Driver for USB Service Cable (page 29) for detailed instructions.

5.1.1 Installing Driver for USB Service Cable

Before taking the USB service cable into use, you must install the provided USB driver on your PC. When installing the driver, you must acknowledge any security prompts that may appear. The driver is compatible with Windows 7, Windows 8, and Windows 10.

1. Check that the USB service cable is not connected. Disconnect the cable if you have already connected it.

2. Insert the media that came with the cable, or download the driver from www.vaisala.com/

software.

3. Execute the USB driver installation program (setup.exe), and accept the installation defaults. The installation of the driver may take several minutes.

4. After the driver has been installed, connect the USB service cable to a USB port on your PC. Windows will detect the new device, and use the driver automatically.

5. The installation has reserved a COM port for the cable. Verify the port number, and the status of the cable, using the Vaisala USB Instrument Finder program that has been installed in the Windows Start menu.

Windows will recognize each individual cable as a dierent device, and reserve a new COM port. Remember to use the correct port in the settings of your terminal program.

There is no reason to uninstall the driver for normal use. However, if you wish to remove the driver ﬁles and all Vaisala USB cable devices, you can do so by uninstalling the entry for Vaisala USB Instrument Driver in Windows Control Panel.

5.1.2 Terminal Application Settings

Table 7 Default Serial Interface Settings

Property Description / Value

Baud rate 19200

Parity None

DMT152 User Guide M210865EN-J

Property Description / Value

Data bits 8

Stop bits 1

Flow control None

The following steps describe how to connect to DMT152 using the PuTTY terminal application for Windows (available for download at www.vaisala.com/software) and a USB serial interface cable:

1. Connect the USB serial interface cable between your PC and the RS-485 port of DMT152 (connector II).

2. Start the PuTTY application.

3. Select the Serial settings category, and check that the correct COM port is selected in the Serial line to connect to ﬁeld.

You can check which port the USB cable is using with the Vaisala USB Instrument Finder program that has been installed in the Windows Start menu.

4. Check that the other serial settings are correct for your connection, and change if necessary. Flow control should be set to None unless you have a reason to change it.

5. Click the Open button to open the connection window and start using the serial line. If PuTTY is unable to open the serial port you selected, it will show you an error message instead. If this happens, restart PuTTY and check the settings.

Chapter 5 – Serial Line Operation

6. You may need to adjust the Local echo setting in the Terminal category to see what you are typing on the serial line. To access the conﬁguration screen while a session is running, click the right mouse button over the session window, and select Change Settings... from the pop-up menu.

5.1.3 List of Serial Commands

All commands can be issued either in uppercase or lowercase. In the command examples, the keyboard input by the user is in bold type.

The notation <cr> refers to pressing the carriage return key (the Enter key) on your computer keyboard. Enter a <cr> to clear the command buer before starting to enter commands.

Note that the term quantity in the serial interface corresponds to measurement parameter.

Table 8 List of Serial Commands

Command Description

ACAL [1/2]

ADDR [0 ... 99] Set the transmitter address for POLL mode

AERR

ALARM

Show device information

Show device information (overrides POLL mode)

Calibrate analog channel

Set analog output device malfunction error mode

Set analog output limit alarm modes

DMT152 User Guide M210865EN-J

Command Description

AMODE

AOVER [ON/OFF]

ASEL

ATEST

Set analog output mode

Allow analog outputs to exceed their range 10 %

Conﬁgure analog output parameter and scaling

Test analog outputs

Close the temporary connection and return the device to POLL mode

ERRS

FORM

FRESTORE

HELP

INTV [0 ... 255

S/MIN/H]

LED

MOL

OPEN [0 ... 99]

PRES

RESET

Display the currently active errors

Change the format of the measurement output

Restore factory settings

Display the command list

Set the continuous output interval (for RUN mode and R command)

Set voltage for LED alarm (not needed with Vaisala LED cable)

Set the molar mass of the process gas (used in ppmw calculation)

Open temporary connection to a device that is in POLL mode

Set value for pressure compensation

Start the continuous outputting

Reset the transmitter

Stop the continuous outputting

SDELAY [0 ... 255] Set response sending delay in milliseconds

SEND [0 ... 99] Output readings once (specify address for transmitters in POLL

mode)

SERI

SMODE [RUN/POLL/STOP]

STAT

STATUS

TIME

UNIT

VERS

XPRES

Set the serial interface settings

Set the serial interface mode

Display transmitter status

Set analog output purge status alarm

Set time for transmitter clock

Select metric or non-metric units

Display transmitter software version

Set value for pressure compensation (temporarily, is cleared at reset)

XPUR [ON/OFF]

Enable or disable sensor purge (temporarily, is enabled at reset)

Chapter 5 – Serial Line Operation

5.2 Device Information

5.2.1 Show Device Information

The ? command outputs a listing of device information.

Table 9 ? command

Syntax Description

?<cr> Display device information.

??<cr> Display device information in POLL mode.

Example:

? DMT152/1.10 Serial number : D1930026 Batch number : D1330070 Module number : ???????? Sensor number : C1420000 Cal. date : 20080512 Cal. info : Vaisala/HEL Serial mode : STOP Baud P D S : 19200 N 8 1 Output interval: 1S Address : 0 Pressure : 1.0132 bar Filter : 1.000 Ch1 output : 0 ... 5 V Ch2 output : U ALARM Ch1 Tdf lo : -80.00 'C Ch1 Tdf hi : 20.00 'C Ch2 Tdf lo : 0.00 'C Ch2 Tdf hi : 0.00 'C

If the transmitter is in POLL mode, but a connection has not been opened using the OPEN command, issue the ?? command. For a description of the serial interface modes, see Set

Serial Line Operating Mode (page 43).

5.2.2 Show Transmitter Status

The STAT command displays the status of the transmitter in 4 characters.

The characters in the output have the following meaning:

[sensor purge] - [output frozen] - [settling] - [status]

During normal measurement all characters are zeroes. When purge is activated, output frozen, or the transmitter is in the settling period after sensor purge, the corresponding status character is 1.

DMT152 User Guide M210865EN-J

The ﬁnal status character can have several values:

0 Normal status 1 Transmitter error 7 Retrying auto-calibration due to ﬂuctuations in the supply voltage 9 Transmitter startup

Some example status codes:

0109 Transmitter performing startup procedure 1100 Sensor purge in progress, output frozen 1110 Settling period after purge, output frozen 0000 Normal measurement

Table 10 STAT command

Syntax Description

STAT<cr> Display the status of the transmitter in 4

Example:

STAT

0000

characters.

It is normal for measurement output to freeze temporarily if the measurement environment is changing rapidly.

5.2.3 Show Firmware Version

Table 11 VERS command

Syntax Description

VERS<cr> Display the transmitter ﬁrmware version

Example:

vers

DMT152 / 1.10

number.

Chapter 5 – Serial Line Operation

5.3 Conﬁguring Analog Outputs

DMT152 has two analog output channels. These channels can function either as normal measurement channels, or produce an ON/OFF output if the measurement exceeds a given alarm level (limit alarm) or if the measurement reading is frozen (for example, during sensor purge).

• In the normal operation mode, a channel outputs voltage or current that corresponds to the reading of the selected measurement parameter.

• In the ON/OFF output mode, a channel outputs a speciﬁed voltage or current level. This mode is used by the limit alarm and the purge status alarm.

• In the LED alarm output mode, the channel outputs operation voltage for the LED cable. The LED will light up to indicate a frozen measurement output which is typically caused by transmitter start-up or sensor purge. The LED will blink at approximately 0.5 Hz if the malfunction alarm is active. The LED will not light up for the limit alarm.

Additionally, DMT152 has a malfunction alarm that is always enabled in normal operation mode. The malfunction alarm can also be enabled for a channel in ON/OFF output mode. See

Malfunction Alarm (page 38).

When the transmitter is ordered from Vaisala, the modes are conﬁgured as speciﬁed in the order form. You can change the operation settings after delivery using the AMODE command:

Table 12 AMODE command

Syntax Description

AMODE [c1 c2]<cr> c1 = Channel 1 analog output mode. Available

options are:

1 0 … 20 mA 2 4 … 20 mA 4 0 … 5 V 5 0 … 10 V 7 I alarm (ON/OFF output using current) 8 U alarm (ON/OFF output using voltage)

Modes 1 … 5 are normal measurement modes, where malfunction alarm is always enabled, and limit alarm and purge status alarm are disabled.

c2 = Channel 2 analog output mode. Available options are:

1 0 … 20 mA 2 4 … 20 mA 4 0 … 5 V 5 0 … 10 V 6 LED alarm 7 I alarm (ON/OFF output using current) 8 U alarm (ON/OFF output using voltage)

Enable mode 6 for channel 2 if you are using the Vaisala LED cable.

DMT152 User Guide M210865EN-J

Syntax Description

Example:

amode 2 1

Ch1 output : 4 ... 20 mA Ch2 output : 0 ... 20 mA

5.3.1 Limit Alarm

The limit alarm is activated when the measured parameter goes below the low limit or above the high limit. The alarm can be speciﬁed during ordering for a speciﬁed parameter, or conﬁgured on the serial line using the ALARM command.

When ordering a limit alarm, the alarm levels are set as follows:

• For current output, an active alarm is indicated by the current being at the maximum of the scale (20 mA).

• For voltage output, an active alarm is indicated by the voltage being at the maximum of the selected scale. For example, if the voltage output scale is 0 … 5 V, an output of 5 V indicates the alarm is active.

Using the ALARM command, you can also set a hysteresis value to prevent the repeated triggering of the alarm when the measurement ﬂuctuates around a limit value.

Table 13 ALARM command

Syntax Description

ALARM ?<cr> View the current alarm settings.

ALARM<cr> Select at the prompt (?) whether the alarm is

enabled or disabled and deﬁne the alarm limits.

Chapter 5 – Serial Line Operation

Syntax Description

The following example shows that a high limit alarm has been enabled for channel 1. If the measured value rises above the -40.00 °C Td limit, analog channel 1 is set to 5 V (Limit Hi = -40.00,

Level Hi = 5.00). The malfunction alarm (aerr) is disabled for both channels.

Note that the term quantity in the serial interface corresponds to measurement parameter.

alarm ?

Channel 1: Low Limit : OFF High Limit : ON Aerr : OFF Quantity : Tdf Limit Lo : 0.00 Limit Hi : -40.00 Hysteresis : 0.00 Level Lo : 0.00 Level Hi : 5.00 Channel 2: Low Limit : OFF High Limit : OFF Aerr : OFF Quantity : ppm Limit Lo : 0.00 Limit Hi : 0.00 Hysteresis : 0.00 Level Lo : 0.00 Level Hi : 0.00

Avoid enabling more than one alarm type for a channel.

5.3.2 Purge Status Alarm

The transmitter can temporarily freeze the output when measurement is not possible (for example, during sensor purge). The purge status alarm indicates this state by setting the analog output at a deﬁned level, in the same way as the limit alarm (see Limit Alarm

(page 36)).

Use the STATUS command to enable/disable the alarm and to deﬁne the voltage/current levels (see example below). The channel is set to the value of Level Hi when sensor purge is active and to Level Lo during normal operation. During auto-calibration, the output is not frozen, that is, the output of the purge status alarm is on Level Lo.

DMT152 User Guide M210865EN-J

Table 14 STATUS command

Syntax Description

STATUS<cr> Select at the prompt (?) whether the alarm is

enabled or disabled and deﬁne the voltage/ current levels.

The following example shows the purge status alarm enabled for channel 1:

status

Channel 1: Status : ON ? Level Lo : 0.00 ? Level Hi : 5.00 ? Channel 2: Status : OFF ? Level Lo : 0.00 ? Level Hi : 0.00 ?

Level Lo and Level Hi are shared between the STATUS and ALARM commands. For example, if you change the levels using the ALARM command, they will also change when viewing the STATUS command.

5.3.3 Malfunction Alarm

If the transmitter is malfunctioning, the channel output is set to a pre-deﬁned level. This overrides the normal measurement output of the channel. You can specify the level using the AERR command:

Table 15 AERR command

Syntax Description

AERR<cr> Enter the error output level at the prompt (?)

for each channel.

Example:

aerr

Ch1 error out : 20.000 mA ? Ch2 error out : 0.000 V ?

The current value is shown after the colon ":". To set a new value, enter it after the question mark. The error output value must be within the valid range for the selected output mode.

The error output value is displayed only when there are minor electrical faults such as a humidity sensor damage. When there is a severe device malfunction, the error output value is not necessarily shown.

Chapter 5 – Serial Line Operation

The malfunction alarm is always enabled for channels that are in the normal measurement modes (see Conﬁguring Analog Outputs (page 35)), but you can enable or disable it using the ALARM command for channels that are in the ON/OFF output mode.

5.3.4 Select Analog Output Parameter and Scaling

Use the ASEL command to select which measurement parameters the analog channels output. See Table 18 (page 41) for the selectable parameters. After entering the command, you will be prompted to enter the scaling of the parameters for both channels. Press the Enter key to accept the suggested scaling values.

Table 16 ASEL command

Syntax Description

ASEL [xxx yyy]<cr> xxx Analog channel 1 output parameter

Example:

asel tdf ppm

Ch1 Tdf lo : -80.00 'C ? Ch1 Tdf hi : 20.00 'C ? Ch2 ppm lo : 0.00 ppm ? Ch2 ppm hi : 1000000.00 ppm ?

yyy Analog channel 2 output parameter

5.4 Conﬁguring Serial Line Operation

5.4.1 Set Serial Line Settings

Use the SERI command to set the serial line settings. The new settings will be taken into use when the transmitter is reset or powered up. Note that the transmitter will use its default serial line settings if it is in error state; see Error State (page 57).

Also note that changing the serial line settings will slightly alter how the transmitter works with the MI70 indicator. If you are not using the default settings of 19200 N 8 1, you will have to power o MI70 before it can ﬁnd the transmitter (you cannot connect it on-the-ﬂy).

Table 17 SERI command

Syntax Description

SERI [b p d s]<cr> B Baud rate (300, 600, 1200, 2400, 4800,

9600, or 19200)

P Parity (n = none, e = even, o = odd) D Data bits (7 or 8) S Stop bits (1 or 2)

DMT152 User Guide M210865EN-J

Syntax Description

Example:

seri 9600 e 7 1

Baud P D S : 9600 E 7 1

5.4.2 Set Serial Line Response Time

With the SDELAY command you can set the delay (response time) of the serial line, or view the currently set delay value.

SDELAY [delay]<cr>

Syntax Description

SDELAY [delay]<cr> [delay] = serial line delay, range 0 … 255. One unit of delay

corresponds to 4 milliseconds.

Example (set delay to 120 milliseconds):

sdelay 30 Serial delay : 30

5.4.3 Set Transmitter Address

To operate in the POLL mode, the transmitter must have an address. If multiple transmitters share the same serial line, each transmitter must have a dierent address.

Syntax

ADDR [address]<cr> [address] = address, range 0 ... 99.

Example:

addr

Address : 0 ?

Description

5.4.4 Set Measurement Output Format

Use the serial line command FORM to change the format or to select the measurement parameters for the output commands SEND and R. You can return to the default format using the FORM / command.

Chapter 5 – Serial Line Operation

Syntax Description

FORM [x]<cr> [x] = formatter string

The formatter string consists of parameters and modiﬁers. The maximum length of the form string is 74 characters. When entering the command, use the abbreviations of the parameters. The parameters are presented in Table 18 (page 41), and modiﬁers in Table 19 (page 41).

FORM /<cr> Return to default format.

Example:

form 4.2 TDF #r #n

form 3.1 “H2O= “ ppm “ “ U3 #r #n

Table 18 FORM Command Parameters

Parameter Description

TDF Dew point / frost point temperature

PPM Water content in parts per million

PPB Water content in parts per billion

PPMW Water content in parts per million by weight

For accurate ppm, ppb, or ppmw reading, you must compensate for the pressure and molar mass of the process gas.

Table 19 FORM Command Modiﬁers

Modiﬁer Description

x.y

#xxx

Length modiﬁer (number of digits and decimal places)

Tabulator

Carriage return

Line feed

String constant

ASCII code value (decimal) of a special character; for example, #027 for Esc

DMT152 User Guide M210865EN-J

Modiﬁer Description

ADDR

ERR

STAT

TIME

Transmitter address with 2 characters (00 … 99)

Currently active transmitter errors in a 9-bit ﬁeld:

bit0 … bit8

• bit0 T MEAS error

• bit1 F MEAS error

• bit2 Voltage too low error

• bit3 Voltage too low for mA output error

• bit4 Ambient temperature error

• bit5 Flash checksum error

• bit6 Parameter checksum error

• bit7 Autocalibration error

• bit8 Internal error

Transmitter serial number

Transmitter status in a 1-character ﬁeld. Transmitter status in 4 characters. The status codes are the same as for the STAT command; see Show Transmitter Status (page 33).

Current time; see the description of the TIME command: Set

Time (page 51).

Shows the name of the measurement unit using “x” number of characters. For example, U3 shows the name of the measurement unit with 3 characters

5.4.5 Select Unit

DMT152 outputs dew point temperature Td in either Celsius or Fahrenheit degrees depending on the unit selection. The unit selection also aects the unit (bara or psia) for the pressure compensation.

Table 20 UNIT command

Syntax Description

UNIT [x]<cr> [x] selects the unit type to output:

• m = metric units (for example, Celsius)

• n = nonmetric units (for example, Fahrenheit)

Example:

unit m

Units : Metric

Chapter 5 – Serial Line Operation

5.4.6 Set Serial Line Operating Mode

Table 21 SMODE Command

Syntax Description

SMODE [xxx]<cr> [xxx] = select the serial line interface mode:

• STOP

• RUN

• POLL See Table 22 (page 43) for a description of the serial modes.

Table 22 Selection of Output Modes

Mode Measurement Output Available Commands

STOP Only with the SEND command. All (default mode).

RUN Automatic output. Only command S.

POLL Only with the SEND [addr]

command.

The polling mode can be used when more than one transmitter is connected to one serial bus. When set to POLL state, the transmitters communicate one at a time when the speciﬁc transmitter address is called on the serial line. See the descriptions of ADDR command (Set

Transmitter Address (page 40)) and OPEN command (Opening the Transmitter in POLL Mode (page 50)).

Selected output mode will be activated at next reset or power up.

Example:

SEND [addr] and OPEN [addr].

Other commands available after opening a line to the transmitter using the OPEN command.

smode poll

Serial mode : POLL

5.5

Conﬁguring Measurement Parameters

5.5.1 Enable or Disable Sensor Purge

You can temporarily disable the sensor purge function using the XPUR command. Note that disabling the sensor purge will aect the measurement performance of the transmitter.

DMT152 User Guide M210865EN-J

Table 23 XPUR command

Syntax Description

XPUR [ON/OFF]<cr> ON = Enable sensor purge

OFF = Disable sensor purge

Example:

xpur off

Purge : OFF

After giving the XPUR OFF command, the transmitter will not perform a sensor purge until one of the following events takes place:

• Transmitter is reset or powered up

• Sensor purge is enabled using the XPUR ON command

5.5.2 Set Pressure Value for ppm Calculation

The DRYCAP 180U sensor in DMT152 is not pressure-dependent. When measuring dew point, pressure compensation is not needed. However, in the calculation of ppm volume concentration, the pressure of the system must be known. If you did not specify pressure compensation when ordering the product, use the commands below to enable the pressure compensation and set the pressure value.

Table 24 PRES and XPRES command

Syntax Description

PRES [pp.pppp]<cr> [pp.pppp] = Absolute pressure in the

XPRES [pp.pppp]<cr> [pp.pppp] = Absolute pressure in the

Use the XPRES command if the value is changed frequently. The value set using the XPRES command overrides the PRES value, but it is not retained at reset. When the XPRES value is set to 0, the last value set with PRES is used instead.

The minimum valid pressure value for both the PRES and XPRES commands is 0.1 bara.

Example:

pres 1.01325

Pressure : 1.01325 bar

measuring point. The unit is bara if metric units have been selected, and psia if non-metric units are used.

Chapter 5 – Serial Line Operation

The pressure conversion coecients from other pressure units to bars are given in Table 25

(page 45).

Table 25 Pressure Conversion Coecients

From To bar

PaN/m

mmHg torr 0.001333224

inHg 0.03386388

mmH2O 0.00009806650

inH2O 0.002490889

atm 1.01325

at 0.980665

psi

0.00001

0.06894757

Example:

29.9213 inHg = 29.9213 × 0.03386388 = 1.01325 bar

Conversions from mmHg and inHg are deﬁned at 0 °C and from mmH2O and inH2O at 4 °C.

You can also set the pressure compensation value when you connect DMT152 to the MI70 indicator. When using MI70, the pressure unit is bara.

5.5.3 Set Molar Mass for ppmw Calculation

Use the MOL command to view and set the molar mass of the gas in the measurement environment. The molar mass parameter is used in calculating H2O ppmw. Some typical molar masses are:

28.96 g/mol

Air N228.0134 g/mol

O232.00 g/mol SF6146.06 g/mol

DMT152 User Guide M210865EN-J

Table 26 MOL command

Syntax Description

MOL [n]<cr> [n] = Molar mass (in g/mol) of the gas in the

Examples:

mol 146.06 Mol : 146.0600

mol Mol : 146.0600 ?

measurement environment.

You can also set the molar mass when you connect DMT152 to the MI70 indicator.

5.6 Serial Line Output Commands

5.6.1 Start Measurement Output

Use the R command to start the continuous outputting of measurement values as an ASCII text string to the serial line. The format of the measurement message is set with the FORM command.

Table 27 R Command

Syntax Description

r<cr> Starts continuous measurement output.

Example:

Tdf= -2.5 'C H2O= 4919 ppm Tdf= -2.5 'C H2O= 4918 ppm Tdf= -2.5 'C H2O= 4917 ppm ...

Outputting the results continues in intervals issued with the command INTV. You can stop the output by pressing the Esc key, or with the command S. Since the interface is half-duplex, you must enter the commands when the transmitter is not outputting.

Chapter 5 – Serial Line Operation

5.6.2 Stop Measurement Output

You can stop the measurement output by pressing the Esc key, or with the S command:

S <cr>

5.6.3 Set Output Interval

Use the INTV command to change the output interval of the automatically repeating measurement messages. The measurement messages are repeated in the RUN mode, or after the R command has been given.

Table 28 INTV Command

Syntax Description

INTV [n xxx]<cr> Set the output interval:

Example:

intv 1 min

Output interval: 1 MIN

The shortest output interval (with n = 0) outputs the measurement messages as quickly as the transmitter’s internal measurement cycle produces them, without additional delay.

n time interval = 0 … 255 xxx time unit = S, MIN, or H

5.6.4 Output a Reading Once

Use the SEND command to output a single measurement message. The output message is sent in the format that has been set using the FORM command.

Syntax

SEND [address]<cr> [address] = address of the transmitter, range 0 … 99.

Example:

send

Tdf= -2.0 'C H2O= 5152 ppm

Description

Must be speciﬁed if the transmitter is in POLL mode, and a line has not been opened using the OPEN command.

DMT152 User Guide M210865EN-J

5.7 Troubleshooting and Maintenance Commands

5.7.1 Display Currently Active Errors

Use the ERRS command to display the currently active transmitter error codes. Possible errors and their causes are listed in Table 37 (page 58).

Table 29 ERRS command

Syntax Description

ERRS<cr> Displays the list of currently active error codes.

Example:

errs

Voltage too low error

5.7.2 Test Analog Outputs

The operation of the analog outputs can be tested with the ATEST command by forcing the output to a given value which can then be measured with calibrated multimeter. The command uses the currently selected analog output types for the channels (voltage or current) so you do not have to specify the unit.

Before testing, you can verify the currently set analog output modes using the AMODE command. After testing the output, give the ATEST command again to exit the test mode.

Table 30 ATEST command

Syntax Description

ATEST [xxx yyy]<cr> Enter the test output values for channel 1 and

channel 2.

xxx Channel 1 output value (V or mA) yyy Channel 2 output value (V or mA)

The output shows the test values of the analog channels as well as diagnostic information that may be useful to Vaisala Service Center if there is a problem with the analog outputs.

Chapter 5 – Serial Line Operation

Syntax Description

Examples:

atest 1 15

1.00 2660

15.00 19425

atest

0.00 79

0.00 20110

5.7.3 Calibrate Analog Output

Use the ACAL command to force the analog outputs to the following values:

• Current output: 2 mA and 18 mA

• Voltage output: 10 % and 90 % of the range

After entering the ACAL command, use a calibrated current/voltage meter to measure the output, and enter the values. Note that the calibration is only valid for the currently selected analog output modes.

Table 31 ACAL command

Syntax Description

ACAL [channel]<cr> [channel] = Analog output channel: 1 or 2

Example:

acal 1

Ch1: I1 ( mA ) ? 0.166 I2 ( mA ) ? 18.1

3.61058569E+02 1.40927863E+03

5.7.4 Extend Analog Output Range

Use the AOVER command to allow the analog output channels to exceed their speciﬁed range by 10 %. The scaling of the measurement parameter remains as before; the extra range is used for additional measurement range in the wet end.

Table 32 AOVER command

Syntax Description

AOVER [ON/OFF]<cr> [channel] = Analog output channel: 1 or 2

DMT152 User Guide M210865EN-J

Syntax Description

Example:

aover on

: ON

The following example illustrates how the analog output is aected.

Channel 1 outputs Td with voltage output 0 … 5 V (-80 °C … -30 °C). After giving the AOVER ON command, the range is 0 … 5.5 V (-80 °C … -25 °C).

Note that the -30 °C Td point is still at 5 V.

5.8 Other Commands

5.8.1 Opening the Transmitter in POLL Mode

Use the OPEN command to connect to a transmitter that is in POLL mode.

Table 33 OPEN command

Syntax Description

OPEN [aa]<cr> [aa] = address of the transmitter to connect to,

Example:

range: 0 … 99.

open 1

DMT152 1 line opened for operator commands

5.8.2 Closing the Connection to a Transmitter in POLL Mode

Use the CLOSE command to close a connection to a transmitter that is in POLL mode.

Table 34 CLOSE command

Syntax Description

CLOSE<cr> Closes the transmitter connection.

Example:

line closed

Chapter 5 – Serial Line Operation

5.8.3 Display Command List

Use the HELP command to display the available commands.

help<cr>

5.8.4 Set Time

Use the TIME command to view and set the transmitter clock. The clock does not have a battery backup – it is reset to 00:00:00 when the transmitter is powered up or reset.

Table 35 TIME command

Syntax Description

TIME

TIME [hh mm ss]<cr> hh Hours (24-hour clock)

Examples:

time 12 30 00

12:30:00

time

12:30:00

Display the current time.

mm Minutes ss Seconds

5.8.5 Reset Transmitter

When the RESET command is given, the transmitter will restart as if it had just been powered on. All transmitter settings are retained. The serial line mode of the transmitter will be set to the mode that was set using the SMODE command.

As the transmitter starts up, it performs the startup sensor purge and auto-calibration before resuming measurement.

RESET<cr>

5.8.6 Set LED Voltage

With the LED command, you can set the supply voltage that is provided to the LED when the LED alarm mode is used. If you are using the Vaisala LED cable, leave this setting at the default voltage (2.80 V).

DMT152 User Guide M210865EN-J

Table 36 LED command

Syntax Description

LED<cr> Enter the LED voltage at the prompt.

Example:

led

Ch 1 Led Voltage : 2.80 V Ch 2 Led Voltage : 2.80 V

5.8.7 Restore Factory Settings

Use the FRESTORE command to restore the factory settings to the transmitter.

FRESTORE<cr>

CAUTION!

command.

All user settings will be lost when you enter the FRESTORE

1 2

3 4

Chapter 6 – Maintenance

6. Maintenance

6.1 Cleaning the Transmitter

The body of the transmitter can be cleaned by wiping with a moistened lint-free cloth. Do not immerse the transmitter in liquid and do not use cleaning agents or solvents. Do not attempt to clean the ﬁlter or the sensor element. If the ﬁlter is contaminated, replace it with a new one.

6.2 Changing the Filter

If the ﬁlter is contaminated, it should be replaced. New ﬁlters can be ordered from Vaisala (order code 220957). Be careful when changing the ﬁlter, since it is easy to break the sensor when the ﬁlter is removed.

CAUTION!

sure that the pressure of the chamber is equalized with the ambient pressure prior to removing the transmitter. When the transmitter is removed for maintenance, cap the hole with a capped nut. This way, the process can be running although the transmitter is not in place. Plugs are available from Vaisala for ISO threaded connections (Vaisala order code 218773) and NPT threaded connections (Vaisala order code 222507).

Figure 16 Filter Structure

Vaisala DRYCAP sensor

1 2 Spring washer 3 Stainless steel mesh ﬁlter (do not touch) 4 Top of the ﬁlter

When replacing the ﬁlter, note the following:

• The pores of the steel mesh may become blocked if touched. Do not touch the ﬁltering surface with your hands or any tools. Always handle the ﬁlter from the top of the ﬁlter body.

• Touching the ﬁlter with your ﬁngers will also deposit oil and dirt on the ﬁlter, which may aect the measurement. Always handle the ﬁlter with gloved hands.

If the transmitter is installed in a pressurized chamber, always make

DMT152 User Guide M210865EN-J

• When installing the transmitter after a ﬁlter change, always use a new sealing ring (ISO and UNF threads only).

Replace the ﬁlter as follows:

1. Grip the old ﬁlter from the top of the ﬁlter body using an 11 mm socket wrench. Turn the ﬁlter counterclockwise until it is loose.

2. Pull the ﬁlter straight out carefully; do not damage the sensor, and do not lose the spring washer.

3. Take the new ﬁlter, and insert it to the ﬁlter threads. The spring washer should be under the ﬁlter.

4. Tighten the new ﬁlter by turning it clockwise with the 11 mm socket wrench. Tighten to 5 Nm.

6.3 Calibration and Adjustment

DMT152 is fully calibrated as shipped from the factory. The recommended calibration interval is 2 years. If the transmitter is used in the wet end of the measurement range, calibration should be done every year. Calibration should also be done if there is a reason to believe that the device is not within its accuracy speciﬁcations.

You can perform a simple ﬁeld checking operation by comparing the readings of DMT152 and DM70 handheld dewpoint meter with a calibrated reference probe. For more information, see

Field Check Using DM70 (page 54).

If there is need for calibration or adjustment, contact a Vaisala Service Center or your local Vaisala representative.

6.3.1 Field Check Using DM70

To check the accuracy of DMT152 in the ﬁeld, you need the following equipment:

• A fully charged MI70 indicator (the measurement display that is included in the DM70 package).

• A calibrated reference probe that is suitable for the intended measurement environment and dew point range. You can use a DMP74 probe from the DM70 for dew point down to −60 °C (−76 °F), or a second DMT152 for full measurement range.

• A connection cable between the DMT152 and the MI70 indicator (Vaisala order code 219980).

• A reference environment with a stable dew point and temperature in a suitable range for both probes. The normal measurement environment of the transmitter can also be used, if it meets these criteria.

Chapter 6 – Maintenance

In the procedure described here, the readings of the probes are checked individually. You can also perform the ﬁeld check so that you connect the reference probe simultaneously with the DMT152 you are checking. In this case, you need two connection cables if you are using a DMT152 also as the reference probe. Also, you must power one of the transmitters by other means than the MI70 indicator.

1. Place DMT152 in the reference environment (unless it is there already). You can perform the check even if DMT152 is currently being powered and used, as long as there is no cable connected to connector II.

2. Connect the MI70 connection cable between the MI70 indicator and connector II of DMT152.

3. Turn on the MI70 indicator. If the analog channels of your DMT152 are conﬁgured to use the current output, and if DMT152 is powered by MI70, you will see an error message that indicates the supply voltage is too low for running the actual analog output. This is expected behavior; press OK to acknowledge the error and continue the ﬁeld check.

4. Check and adjust the environment settings if prompted. You can change the pressure compensation value (only needed for ppm calculation) and the molar mass of the measurement gas. The pressure must be entered in bara; to enter the value in psia, use the

serial line. For more information on these settings, see the following sections:

• Set Pressure Value for ppm Calculation (page 44)

• Set Molar Mass for ppm w Calculation (page 45)

5. After a brief delay, DMT152 should provide an approximate measurement reading of the selected parameters. Remember that it takes up to 15 minutes for the transmitter to start the active measurement. If the desired parameters are not shown on the display, select them from the Display – Quantities and units menu.

6. The Auto power o function should be disabled on the MI70 indicator to prevent the indicator from powering o in the middle of the check. While waiting for the active measurement to start, check the setting in the Settings - User Interface menu, and change if necessary.

7. Write down the Td reading after the measurement has stabilized.

8. Turn o the MI70 indicator and disconnect DMT152.

9. Insert the reference probe to the measurement environment, and connect it to the MI70 indicator.

10. Turn on the MI70 indicator. Check and adjust the environment settings if prompted.

DMT152 User Guide M210865EN-J

11. Wait for the reference probe to provide a stable reading, and compare it with the reading from DMT152.

The dierence between the readings will give you an indication of the approximate drift of DMT152 and its need for calibration. As a general rule, the reading from DMT152 should be within ±4 °C Td of the reading from the reference probe.

Some notes on using the MI70 indicator with the DMT152:

• If you disconnect DMT152 while the MI70 indicator is on, the parameters measured will remain on the screen, but no measurement will be shown.

• The messages from the transmitter (such as the supply voltage error) will appear in English even if MI70 has been set to another language.

Chapter 7 – Troubleshooting

7. Troubleshooting

7.1 Typical Problems

If you have a problem with DMT152, ﬁrst read the following sections concerning the behavior and error indications of the transmitter:

• Conﬁguring Analog Outputs (page 35)

• Error State (page 57)

• Error Codes (page 58)

Possible causes of errors include insucient supply voltage, excessive supply voltage ﬂuctuation, physical damage to the transmitter, and incorrect connections. Connection problems can be caused by misconﬁguration of the analog outputs or the serial line. Also remember that the startup of the transmitter may take up to 15 minutes.

Some problems can be solved by simply resetting the transmitter. You can reset the transmitter by disconnecting the power or issuing the RESET command on the serial line.

If you cannot locate the source of the error and return the transmitter to the normal state, contact Vaisala technical support. See www.vaisala.com/support for more information.

7.2

Unknown Serial Settings

If you are not sure what the serial settings of your transmitter are, follow these steps to view and change the settings.

1. Make sure there are no other transmitters on the serial line.

2. Provide the transmitter with a 9 V supply voltage. This voltage is enough to start it in the error state.

3. Connect to the serial line using the error state serial line settings 19200 N 8 1.

4. Give the ? command to view the transmitter settings, including the serial settings and address. For an output example, see Show Device Information (page 33). You may have to give the command several times if there are characters in the buer.

5. If necessary, set new serial line settings using the SERI command. For instructions on using the command, see Set Serial Line Settings (page 39).

7.3

Error State

If the voltage supplied to DMT152 is too low for reliable operation, or ﬂuctuates heavily, or there is some serious problem that prevents measurement, DMT152 will enter an error state. The error state is indicated by the following:

• Analog current output at 0 mA or 4 mA (according to selected range)

• Analog voltage output at 0 V

DMT152 User Guide M210865EN-J

• Serial line outputs asterisk characters "*" instead of measurement data. For example:

Tdf=****** 'C H2O=****** ppm

The analog output levels for the error state are conﬁgurable using the AERR command; see

Malfunction Alarm (page 38). Note that the asterisk characters on the serial line may also

appear during the startup procedure. When the transmitter is in the error state, it will use the default serial interface settings, regardless of the currently set serial interface mode. If you have set a dierent mode with the SERI command, you will have to set your terminal program to the default settings of 19200 N 8 1 (see Terminal Application Settings (page 29)) before you can connect to the transmitter in error state.

7.4 Error Codes

The transmitter has error codes that can be displayed on the serial line using the ERRS command. See section Display Currently Active Errors (page 48).

Table 37 Error Codes

Error Code Cause

Ambient temperature error Ambient temperature out of operating range

Autocal error Transmitter unable to complete auto-calibration

Voltage error Supplied operating voltage is too low or high for

Voltage too low error Supplied operating voltage is too low for reliable

(probably too hot).

after several attempts. Can be caused by continuously changing measurement environment, problem with supply voltage, or transmitter malfunction.

reliable operation, or there is a problem with voltage measurement.

operation.

Chapter 7 – Troubleshooting

Error Code Cause

Voltage too low for mA output error Supplied operating voltage is too low for reliable

operation of the analog current output.

It is normal to receive this error when using the MI70 indicator or the USB serial interface cable, as they do not provide a sucient operating voltage to operate the current output. To avoid this error, connect a power supply for the transmitter to connector I before connecting the MI70 indicator or USB cable. See

Power Supply Requirements (page 19).

T meas error Internal error, can be caused by damage to the

F meas error Internal error, can be caused by damage to the

Internal error Transmitter unable to function. Can be caused

Parameter ﬂash check sum error Internal error

Program ﬂash check sum error Internal error

INFOA check sum error Internal error

SCOEFS check sum error Internal error

CURRENT check sum error Internal error

Unknown error Internal error

sensor.

by transmitter malfunction or unsuitable measurement environment.

DMT152 User Guide M210865EN-J

8. Technical Data

8.1 Speciﬁcations

Table 38 Measurement Performance

Property Description/Value

Sensor Vaisala DRYCAPâ 180U

Thin-ﬁlm capacitive polymer sensor

Recommended calibration interval 2 years

Dew Point Temperature

Measurement range −80 … −20 °C (−112 … −4 °F) T

Accuracy

−80 … −40 °C (−112 … −40 °F) ±2 °C (3.6 °F) T

−40 … −20 °C (−40 … −4 °F) ±3 °C (5.4 °F) T

Non-calibrated range −100 … +20 °C (−148 … +68 °F) T

Typical response time 63 % [90 %] at a gas temperature of +20 °C (+68 °F) and pressure of 1 bar:

−20 … −80 °C T

−80 … −20 °C T

Typical long-term stability Better than 2 °C (3.6 °F) / year

Analog Output Scalings

Option 1 −80 … +20 °C (−112 … +68 °F) T

Option 2 −100 … 0 °C (−148 … +32 °F) T

Option 3 Free scaling

Concentration by Volume (ppm)

Measurement range (typical) 0 … 500 ppm

Accuracy at +20 °C (+68 °F), 1013 mbar ±(0.2 ppm + 20 % of reading)

0.5 min [7.5 min]

2 s [5 s]

1) When the dew point is below 0 °C, the transmitter outputs frost point for Td.

Dew point temperature (°C)

-40

-20 0

-60

-80

-10

-20

-30

-50

-40

-70

-10-30 10

40 50 60

-90

-100

Temperature of measured gas (°C)

Area not recommended

for continuous measurement

Accuracy not speciﬁed

Accuracy ±3 °C Td

Accuracy ±2 °C Td

Accuracy not speciﬁed

Chapter 8 – Technical Data

Figure 17 Accuracy Over Temperature Range

Table 39 Operating Environment

Property Description/Value

Temperature −40 … +70 °C (−40 … +158 °F)

Relative humidity 0 … 100 %RH (up to +20 °C / +68 °F)

Pressure 0 … 50 bar (725 psia)

Measured gases Non-corrosive gases

Sample ﬂow rate No eect on measurement accuracy

EMC compliance EN61326-1, Industrial environment

Table 40 Inputs and Outputs

Property Description/Value

Two analog outputs (scalable) 4 … 20 mA, 0 … 20 mA (3-wire) 0 … 5 V, 0 … 10 V

Digital output RS-485 (2-wire)

Alarm-level indication by analog signal User selectable

Purge information 5 V, 10 V, 20 mA, or LED

Accuracy of analog outputs ±0.01 V / ±0.01 mA

ON/OFF Output Available Instead of 2nd Analog Output

Purge inactive 0 V or 4 mA

Purge active 5 V, 10 V, or 20 mA

OR exceeded Td or ppm limit User selectable

DMT152 User Guide M210865EN-J

Property Description/Value

Typical Temperature Dependence

Voltage output ±0.001 % of span / °C

Current output ±0.005 % of span / °C

Operating Voltage

RS-485 output

Voltage output

11 … 28 VDC

15 … 28 VDC

Current output 21 … 28 VDC

Supply Current

Normal measurement 20 mA + load current

During self-diagnostics Max. 220 mA pulsed

Supply voltage ﬂuctuation Max. 0.3 V

External Load

Voltage output Min. 10 kΩ

Current output Max. 500 Ω

1) For extended temp. down to −40 °C (−40 °F) or pressure up to 50 bar (725 psia), the supply voltage is 21 … 28 VDC.

Table 41 Mechanical Speciﬁcations

Property Description/Value

Housing material (wetted parts) AISI316L

Stainless steel mesh ﬁlter Filter body AISI303, mesh AISI316L, grade 18 μm

Mechanical connections ISO G1/2", NPT 1/2", UNF 3/4"- 16", UNF 5/8"-18"

IP rating IP66

Storage temperature range −40 … +80 °C (−40 … +176 °F)

Weight with dierent thread options ISO thread: 190 g (6.70 oz)

NPT thread: 210 g (7.41 oz)

UNF thread: 186 g (6.56 oz)

Table 42 Output Cable Speciﬁcations

Property Speciﬁcation

Connector Straight, moulded M8 female (IEC 60947-5-2)

Property Speciﬁcation

Color Black

Number of contacts 4

Conductors

Insulation PVC

Cable diameter 5.0 mm / 0.2 in

Protection class IP67 / NEMA 4

Wire color code EN50044

0.25 mm2 (× 4) / 0.00039 inch2 (× 4)

8.2 Spare Parts and Accessories

Table 43 Accessories

Item Order Code

Connection cable for MI70 handheld indicator 219980

USB cable for PC connection 219690

Sealing ring set ISO (copper, 3 pcs) 221524SP

Sealing ring set UNF (copper, 3 pcs) 221563SP

Stainless steel mesh ﬁlter (18 µm) 220957SP

110 … 240 VAC external power supply POWER-1

Plug kit (ISO 1/2") 218773

Plug kit (NPT 1/2") 222507

Loop-powered external display (Nokeval 301) 226476

Loop-powered external display with relays (Nokeval 302)

NW40 ﬂange 225220SP

Analog/RS-485 Output Cables

2 m (6,5 ft) cable, M8 snap-on connector 211598

3 m (9.8 ft) cable, Ch1 signal + Ch2 LED, M8 threaded connector

0.32 m (1 ft) shielded cable, M8 threaded connector

3 m (9.8 ft) shielded cable, M8 threaded connector

234759

MP300LEDCBL

HMP50Z032

HMP50Z30ASP

Chapter 8 – Technical Data

DMT152 User Guide M210865EN-J

Item Order Code

5 m (16.4 ft) shielded cable, M8 threaded

HMP50Z500SP

connector

10 m (32.8 ft) shielded cable, M8 threaded

HMP50Z1000SP

connector

Sampling Cells (Available for ISO G1/2")

Basic sampling cell DMT242SC

With Swagelok 1/4" male connectors DMT242SC2

With a quick connector and leak screw DSC74

Two-pressure sampling cell DSC74B

Separate cooling/venting coil for sampling cells DMCOIL

8.3 Dimensions

76 [2.99]

29.5

[1.16]

[0.47]

32.5 [1.28]

120.5 [4.74]

G 1/2" ISO 228-1

[1.3]

AW30[1.18]

29.5

[1.16]

128.5 [5.06]

76 [2.99]

32.5 [1.28]

[0.47]

1/2" NPT

29.5

[1.16]

120.5 [4.74]

32.5 [1.28]76 [2.99]

[0.47]

3/4"-16 UNF

5/8"-18 UNF

[0.47]

120.5 [4.74]

32.5 [1.28]76 [2.99]

29.5

[1.16]

mm [in]

Chapter 8 – Technical Data

Figure 18 DMT152 Dimensions

DMT152 User Guide M210865EN-J

Warranty

For standard warranty terms and conditions, see 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.

Technical Support

Contact Vaisala technical support at helpdesk@vaisala.com. Provide at least the following supporting information as applicable:

• Product name, model, and serial number

• Software/Firmware version

• Name and location of the installation site

• Name and contact information of a technical person who can provide further information on the problem

For more information, see www.vaisala.com/support.

Recycling

Recycle all applicable material.

Follow the statutory regulations for disposing of the product and packaging.

DMT152 User Guide M210865EN-J

www.vaisala.com

Vaisala DRYCAP DMT152 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Table of Contents

List of Figures

List of Tables

1. About This Document

1.1 Version Information

1.2 Related Manuals

Documentation Conventions

1.4 Trademarks

2. Product Overview

2.1 Introduction to DMT152

2.1.1 Basic Features and Options

2.1.2 Transmitter Structure

2.1.3 Safety

2.1.4 ESD Protection

2.1.5 Regulatory Compliances

3. Functional Description

3.1 Advanced DRYCAP Technology

3.1.1 Auto-Calibration

3.1.2 Sensor Purge

4. Installation

4.1 Selecting the Location

Installing the Transmitter

4.3 Wiring

4.3.1 Output Noise Minimization Option

4.3.2 Connection Cables

4.3.3 Power Supply Requirements

4.4 Loop-Powered Display

Sampling from Process

Sampling Accessories

4.6.1 DMT242SC Sampling Cell

4.6.2 DMT242SC2 Sampling Cell with Swagelok Connectors

4.6.3 DSC74 Sampling Cell with Quick Connector and Leak Screw

4.6.4 DSC74B Two-Pressure Sampling Cell

4.6.5 DSC74C Two-Pressure Sampling Cell with Coil

4.6.6 NW40 Mounting Flange

5. Serial Line Operation

5.1 Connecting to Serial Interface

5.1.1 Installing Driver for USB Service Cable

5.1.2 Terminal Application Settings

5.1.3 List of Serial Commands

5.2 Device Information

5.2.1 Show Device Information

5.2.2 Show Transmitter Status

5.2.3 Show Firmware Version

5.3.1 Limit Alarm

5.3.2 Purge Status Alarm

5.3.3 Malfunction Alarm

5.3.4 Select Analog Output Parameter and Scaling

5.4.1 Set Serial Line Settings

5.4.2 Set Serial Line Response Time

5.4.3 Set Transmitter Address

5.4.4 Set Measurement Output Format

5.4.5 Select Unit

5.4.6 Set Serial Line Operating Mode

5.5.1 Enable or Disable Sensor Purge

5.5.2 Set Pressure Value for ppm Calculation

5.5.3 Set Molar Mass for ppmw Calculation

5.6 Serial Line Output Commands

5.6.1 Start Measurement Output

5.6.2 Stop Measurement Output

5.6.3 Set Output Interval

5.6.4 Output a Reading Once

5.7 Troubleshooting and Maintenance Commands

5.7.1 Display Currently Active Errors

5.7.2 Test Analog Outputs

5.7.3 Calibrate Analog Output

5.7.4 Extend Analog Output Range

5.8 Other Commands

5.8.1 Opening the Transmitter in POLL Mode

5.8.2 Closing the Connection to a Transmitter in POLL Mode

5.8.3 Display Command List

5.8.4 Set Time

5.8.5 Reset Transmitter

5.8.6 Set LED Voltage

5.8.7 Restore Factory Settings

6. Maintenance