USER'S GUIDE Vaisala HUMICAP® Dewpoint Transmitter DMT132 M211289EN-A
PUBLISHED BY Vaisala Oyj P.O. Box 26 FI-00421 Helsinki Finland Phone (int.): +358 9 8949 1 Fax: +358 9 8949 2227 Visit our Internet pages at www.vaisala.com. © Vaisala 2011 No part of this manual may be reproduced in any form or by any means, electronic or mechanical (including photocopying), nor may its contents be communicated to a third party without prior written permission of the copyright holder. The contents are subject to change without prior notice.
________________________________________________________________________________ Table of Contents CHAPTER 1 GENERAL INFORMATION............................................................................ 5 About This Manual ................................................................... 5 Contents of This Manual ....................................................... 5 Version Information ............................................................... 6 Related Manuals ...............................
USER'S GUIDE____________________________________________________________________ CHAPTER 4 OPERATION.................................................................................................33 Getting Started........................................................................33 Serial Communication............................................................33 Connecting to the Serial Interface .......................................33 Installing the Driver for the USB Service Cable .............
________________________________________________________________________________ Technical Support .................................................................. 66 Product Returns ..................................................................... 66 CHAPTER 7 TECHNICAL DATA ...................................................................................... 67 Specifications ......................................................................... 67 Performance...................................
USER'S GUIDE____________________________________________________________________ List of Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 Figure 20 Figure 21 Figure 22 Figure 23 Figure 24 Figure 25 Figure 26 Figure 27 Figure 28 Figure 29 Figure 30 Vaisala HUMICAP® Dewpoint Transmitter DMT132 ................10 DMT132 Transmitter Structure .............................
Chapter 1 ________________________________________________________ General Information CHAPTER 1 GENERAL INFORMATION This chapter provides general notes for the manual and the DMT132. About This Manual This manual provides information for installing, operating, and maintaining the Vaisala HUMICAP® Dewpoint Transmitter DMT132. Contents of This Manual This manual consists of the following chapters: - Chapter 1, General Information, provides general notes for the manual and the DMT132.
USER'S GUIDE____________________________________________________________________ Version Information Table 1 Manual Code M211289EN-A Manual Revisions Description March 2011. This manual. First version.
Chapter 1 ________________________________________________________ General Information Safety The Vaisala HUMICAP® Dewpoint Transmitter DMT132 delivered to you has been tested for safety and approved as shipped from the factory. Note the following precautions: WARNING Ground the product and verify outdoor installation grounding periodically to minimize shock hazard. CAUTION Do not modify the unit. Improper modification can damage the product or lead to malfunction.
USER'S GUIDE____________________________________________________________________ Regulatory Compliances The Vaisala HUMICAP® Dewpoint Transmitter DMT132 is in conformity with the provisions of the following EU directive(s): - EMC-Directive (2004/108/EC) 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.
Chapter 2 __________________________________________________________ Product Overview CHAPTER 2 PRODUCT OVERVIEW This chapter introduces the features, options, and accessories of the DMT132. Introduction to DMT132 The Vaisala HUMICAP® Dewpoint Transmitter DMT132 measures dewpoint temperature accurately in a measurement range -20 ... +50 °C (-4 ... +122 °F) Td. The DMT132 is designed for OEM applications that require dewpoint measurement in this range, such as refrigeration dryers.
USER'S GUIDE____________________________________________________________________ 1101-047 Figure 1 ® Vaisala HUMICAP Dewpoint Transmitter DMT132 Basic Features and Options - Dewpoint measurement range -20 ... +50 °C (-4 ... +122 °F) Td. Output in Td/f or Td/f atm (calculated quantity). HUMICAP® polymer sensor . Small size to fit in tight installations. One scalable 2-wire current loop output, 4 ... 20 mA. Configurable analog output level for error notification.
Chapter 2 __________________________________________________________ Product Overview Transmitter Structure The structure of the DMT132 is shown in Figure 2 on page 11. The transmitter body does not have user serviceable parts inside, and is not designed to be opened. Opening the transmitter will void the warranty.
USER'S GUIDE____________________________________________________________________ LED Indicator Plug (Optional) The service port (connector II) of the DMT132 can be equipped with a LED indicator plug (Vaisala order code 230388). The red LED on the plug will light up when the measured dewpoint temperature is above the set limit. If the transmitter is in error condition, the LED will blink.
Chapter 2 __________________________________________________________ Product Overview Special Cover Set for HMK15 (Optional) To use the Vaisala Humidity Calibrator HMK15 with the DMT132 you need the special cover set (Vaisala order code 230914). The cover set includes one salt jar cover where one of the holes is specially designed for the DMT132, and rubber plugs for covering the unused holes. The hole for DMT132 is raised higher than the others, and has an ISO G 1/2" thread.
USER'S GUIDE____________________________________________________________________ NPT Adapter (Optional) The DMT132 can be connected to NPT 1/2" threaded mounting points using the optional NPT adapter (Vaisala order code 210662). 1101-061 Figure 5 NOTE DMT132 with NPT Adapter When the NPT adapter is used, the filter is partially covered by the adapter; see Figure 5 above. This doubles the response time of the transmitter.
Chapter 2 __________________________________________________________ Product Overview Loop-Powered Display (Optional) The DMT132 can be connected to a loop-powered external LED display (type Nokeval 301, Vaisala order code 226476). The display provides a reading of the output quantity. The display is powered by the 4 ... 20 mA current signal, so there is no need for an external power supply. The display is delivered at its default settings.
USER'S GUIDE____________________________________________________________________ Connection Cables Vaisala supplies shielded cables with M8 female straight threaded connector. Available in four lengths: - 0.3 m (1.0 ft) 3 m (9.8 ft) 5 m (16.4 ft) 10 m (32.8 ft) Also available are cables for service port and field check use: - USB service cable - MI70 connection cable For the order codes of the cables, refer to section Spare Parts and Accessories on page 69.
Chapter 2 __________________________________________________________ Product Overview Sampling Accessories DMT132 is compatible with various sampling accessories. For more information on performing sampling, and a description of the accessories, see section Sampling Accessories on page 17. For the order codes of the sampling accessories, refer to section Spare Parts and Accessories on page 69.
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Chapter 3 _______________________________________________________________ Installation CHAPTER 3 INSTALLATION This chapter provides you with information that is intended to help you install the DMT132. 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 affect the dewpoint measurement, but pressure changes will have an effect on dewpoint.
USER'S GUIDE____________________________________________________________________ Installing the Transmitter After selecting a suitable measurement location, follow the procedure below to install the transmitter: 1. Remove the yellow transport protection cap from the transmitter. 1101-062 Figure 9 2. 3. Removing the Transport Protection Cap If you are using the optional NPT adapter, apply PTFE tape or suitable paste sealant to the outer thread of the adapter.
Chapter 3 _______________________________________________________________ Installation 1101-063 Figure 11 4. CAUTION Tightening by Hand Use the supplied plastic 30 mm wrench to tighten the connection. Sufficient tightness is achieved by turning 20 degrees after the point achieved by hand. Only tighten the transmitter from the 30 mm nut. Do NOT apply force to other points in the transmitter body.
USER'S GUIDE____________________________________________________________________ 5. Connect the wires of the connection cable. When using cables provided with DMT132 refer to the wiring section on page 23. See the power supply requirements on page 24. 1101-066 Figure 13 6. 7. 8. Connecting the Cable and LED Indicator Plug Plug in the cable to connector I of the transmitter and tighten it. For connector pinout, see section Wiring on page 23.
Chapter 3 _______________________________________________________________ Installation Wiring CAUTION The power supply lines on connector II are intended for use by the USB service cable and the MI70 hand-held indicator. Do not connect other power supplies to connector II.
USER'S GUIDE____________________________________________________________________ Power Supply Requirements The DMT132 transmitters are designed to operate with a supply voltage of 10 ... 28 VDC. The allowed voltage range depends on the loop resistance (RL): - For RL 0 ... 100 Ω, supply voltage range is 10 ... 20 VDC. - For RL 0 ... 500 Ω, supply voltage range is 20 ... 28 VDC. NOTE Maximum allowed RL is 600 Ω, as long as the following equation applies: U min RL 7.
Chapter 3 _______________________________________________________________ Installation Sampling Accessories 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). Refer to Figure 16 on page 26.
USER'S GUIDE____________________________________________________________________ 0801-069 Figure 16 Sampling Cells DMT242SC2 (left) and DMT242SC (right) where 1 2 3 4 = = = = Male pipe welded connector Swagelok 1/4" G1/2" G1/4" G3/8" 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.
Chapter 3 _______________________________________________________________ Installation 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.
USER'S GUIDE____________________________________________________________________ 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.
Chapter 3 _______________________________________________________________ Installation 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.
USER'S GUIDE____________________________________________________________________ 0403-113 Figure 21 Alternative Assembly of DSC74C (for Tight Spaces) where 1 2 3 4 5 = = = = = Gas comes out Coil Thread, max. size 7 mm Gas goes in Valve The thread size cannot exceed 7 mm. Use the provided adapter to avoid damage to the transmitter.
Chapter 3 _______________________________________________________________ Installation DM240FA Duct Installation Flange The transmitter can be installed directly in the process wall through DM240FA duct installation flange. When the transmitter is installed directly on the process wall or pipe, note that a closing valve may be needed on both sides of the installed transmitter so that the sensor head can be removed from the process for calibration or maintenance.
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Chapter 4 ________________________________________________________________ Operation CHAPTER 4 OPERATION This chapter contains information that is needed to operate the DMT132. Getting Started When the transmitter is connected to power supply, there is a delay of three seconds as the transmitter starts up and the analog output stabilizes. If the LED indicator plug is connected, it will blink once at start-up.
USER'S GUIDE____________________________________________________________________ 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. 3. Execute the USB driver installation program (setup.exe), and accept the installation defaults. The installation of the driver may take several minutes. 4.
Chapter 4 ________________________________________________________________ Operation 3. 4. 5. 6. Select the Serial settings category, and check that the correct COM port is selected in the Serial line to connect to field. Note: 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. Check that the other serial settings are correct for your connection, and change if necessary.
USER'S GUIDE____________________________________________________________________ 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 refers to pressing the carriage return (Enter) key on your computer keyboard. Enter a to clear the command buffer before starting to enter commands.
Chapter 4 ________________________________________________________________ Operation Device Information and Status Show Device Information The ? command outputs a listing of device information.
USER'S GUIDE____________________________________________________________________ Show Software Information SYSTEM Example: >system Device Name Copyright rights reserved. SW Name SW model SW version > : DMT132 Dewpoint transmitter : Copyright (c) Vaisala Oyj 2011. All : DMT132 : VAISALA : 1.0.0.1214 Configuring Analog Output Set Analog Output Quantity and Scaling Use the ASEL command to show or set the output quantity and the scaling of the analog output.
Chapter 4 ________________________________________________________________ Operation Example (change output to TDF, low limit to -10 and high limit to 30): >asel tdf -10 30 Quantity : TDF Saving settings...done Level Lo : -10 Saving settings...done Level Hi : 30 Saving settings...done > Set Analog Output Error Notification If the transmitter is malfunctioning, the analog output is set to a predefined level of 3.8 mA. This overrides the normal measurement output of the channel.
USER'S GUIDE____________________________________________________________________ Configuring Measurement Parameters Set Pressure Value for Dewpoint Calculation The HUMICAP® 180R sensor in the DMT132 is not very pressuredependent. However, to maximize the measurement accuracy, the pressure of the system must be known. The pressure compensation value has been set at the factory according to the order form. You can view and set a new value using the PRES command.
Chapter 4 ________________________________________________________________ Operation NOTE Conversions from mmHg and inHg are defined at 0 °C and from mmH2O and inH2O at 4 °C. NOTE You can also set the pressure compensation value when you connect the DMT132 to the MI70 indicator. When using the MI70, the pressure unit is bara. Serial Line Output Commands Output a Reading Once Use the SEND command to output a single measurement message.
USER'S GUIDE____________________________________________________________________ Test Analog Output The operation of the analog output can be tested with the ATEST command by forcing the output to a given value which can then be measured with a calibrated multimeter. After testing the output, give the ATEST command again to exit the test mode. ATEST [mA] where mA = Analog output value, range 0 ... 30 mA.
Chapter 4 ________________________________________________________________ Operation Example (enable the LED indicator at dewpoint above 20 °C): >alarm on 20 Alarm level : 20.000000 Saving settings...done > Calibration and Adjustment Commands Commands that have to do with calibration and adjustment on the serial line are described below. For the calibration and adjustment procedures, see section Calibration and Adjustment on page 52.
USER'S GUIDE____________________________________________________________________ Calibrate Temperature Measurement Use the CT command to perform a one-point or two-point temperature (T) calibration. CT When performing a one-point calibration, you need to place the transmitter in a single temperature reference. Run the command and enter the exact temperature of the reference after the measurement has stabilized.
Chapter 4 ________________________________________________________________ Operation Adjust Capacitance Measurement Use the CRH command to perform a one-point or two-point correction to the capacitance measurement of the transmitter. This command changes the offset and gain of the measured capacitance, and therefore affects humidity measurement over the entire temperature range.
USER'S GUIDE____________________________________________________________________ View User Adjustment Parameters Use the L command to view the current user adjustment parameters that are affected by the CRH, RHCAL, CT, and LI commands. This command is useful for checking the currently applied correction. L The output values are as follows: - Cp offset and gain: capacitance, adjusted using the CRH command. - RH offset and gain: adjusted using the RHCAL command.
Chapter 4 ________________________________________________________________ Operation Other Commands Display Command List HELP Example: >help ? AERR ALARM ASEL ATEST CALCS CRH CT ERRS FRESTORE HELP L LI PASS PRES RHCAL RESET SEND SYSTEM VERS > 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. RESET Example: >reset DMT132 1.0.
USER'S GUIDE____________________________________________________________________ Restore Factory Settings Use the FRESTORE command to restore the factory settings to the transmitter. All user settings will be lost, and the transmitter will return to the factory calibrated state (user adjustment is cleared). FRESTORE Example: >frestore Restoring factory defaults...done Saving settings...
Chapter 5 ______________________________________________________________ Maintenance CHAPTER 5 MAINTENANCE This chapter provides information that is needed in basic maintenance of the DMT132. 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 elements. If the filter is contaminated, replace it with a new one.
USER'S GUIDE____________________________________________________________________ When replacing the filter, note the following: - Touching the filter with your fingers will also deposit oil and dirt on the filter, which may affect the measurement. Always handle the filter with gloved hands. - When installing the transmitter after a filter change, inspect the sealing ring first. Use a new one if the old ring is visibly damaged.
Chapter 5 ______________________________________________________________ Maintenance 3. 4. Take the new filter, and insert it to the filter threads. The spring washer should be under the filter. A new washer is not included with the filter, so reuse the old one. Tighten the new filter by turning it clockwise. Do not use tools to tighten the filter, finger tightness is enough. Changing the Sensor The user can replace the HUMICAP® 180R sensor with a new one.
USER'S GUIDE____________________________________________________________________ Calibration and Adjustment The DMT132 is fully calibrated as shipped from factory. The recommended calibration interval is 2 years in refrigerator dryer applications. If the transmitter is used in the dry 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 the accuracy specifications.
Chapter 5 ______________________________________________________________ Maintenance Field Check Using DM70 To check of the accuracy of the DMT132 in the field, you need the following equipment: - A fully charged MI70 indicator (the measurement display that is included in the DM70 and HM70 hand-held indicator products) - A calibrated reference probe that is suitable for the intended measurement environment and dewpoint range.
USER'S GUIDE____________________________________________________________________ 5. 6. 7. 8. 9. 10. 11. If the desired quantities are not shown on the display, select them from the Display – Quantities and units menu. The Auto power off function should be disabled on the MI70 indicator to prevent the indicator from powering off 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.
Chapter 5 ______________________________________________________________ Maintenance Humidity Calibration and Adjustment (RHCAL) The procedure below describes a humidity measurement calibration and adjustment using the serial line commands and the Vaisala Humidity Calibrator HMK15. You can use the procedure to do a one-point calibration (offset) or a two-point calibration (offset and gain).
USER'S GUIDE____________________________________________________________________ 1. 2. 3. 4. Disconnect the cable from connector I of the DMT132 (if connected). Connect the USB cable to connector II on the DMT132, and to a USB port on your PC. Start a terminal application and set the service port connection settings (19200 8 N 1). Remember to check which COM port the USB cable is using. Verify that the connection works by giving the ? command: >? 5.
Chapter 5 ______________________________________________________________ Maintenance 11. 12. When the measurement shown by RHCAL is stable, you can either apply the correction or exit the procedure: - To apply the correction, press ENTER one last time to update the value, type 11 and press ENTER again (assuming you are using the HMK15 and the LiCl salt). - To exit the RHCAL command without adjusting the measurement, press the ESC key and exit this procedure.
USER'S GUIDE____________________________________________________________________ Temperature Calibration and Adjustment (CT) The procedure below describes a temperature (T) measurement calibration and adjustment using serial line commands. You can use the procedure to do a one-point calibration (offset) or a two-point calibration (offset and gain). For two-point calibration, the second reference point must be at least 20 ºC warmer than the first. 1. 2. 3. 4.
Chapter 5 ______________________________________________________________ Maintenance 9. Wait for 20 ... 40 minutes for the reading to stabilize. Press ENTER without typing anything to update the value shown by the CT command. T T T 10. 11. 22.1298 Ref1 ? 22.1317 Ref1 ? 22.
USER'S GUIDE____________________________________________________________________ Capacitance Adjustment (CRH) CAUTION Adjusting the capacitance measurement affects measurement accuracy across the entire temperature range. This command should be used only when the sensor has been replaced, or the measurement has drifted significantly. After sensor change, you must perform the two-point capacitance adjustment. For normal adjustment, use the RHCAL command instead.
Chapter 5 ______________________________________________________________ Maintenance 5. When your serial connection is working, use the L command to see the current user adjustment parameters. Write down the Cp offset and gain values so you can restore them manually using the LI command, if necessary. >l 6. Use the ERRS command to see that no errors are active: >errs 7. 8. 9. Install the HMK15 calibrator fitting over the LiCl salt chamber of the humidity calibrator (11 %RH).
USER'S GUIDE____________________________________________________________________ 12. If you only want to perform a one-point adjustment (offset correction), press the ESC key after entering the correction. The CRH command will exit, and you can move to step 16. RH: 11.35423321 Ref1 ? 11 Press any key when ready > 13. 14. To continue with the adjustment of the wet end (gain correction), press ENTER. Insert the DMT132 in the NaCl salt chamber (75 %RH).
Chapter 6 ___________________________________________________________ Troubleshooting CHAPTER 6 TROUBLESHOOTING This chapter describes common problems, their probable causes and remedies, and provides contact information for technical support.
USER'S GUIDE____________________________________________________________________ Error State If the voltage supplied to the DMT132 is too low for reliable operation, or there is some serious problem that prevents measurement, the DMT132 will enter an error state. The error state is indicated by the following: - Analog current output is set to the error level (default is 3.8 mA) - If the LED indicator plug option is installed, the LED is blinking.
Chapter 6 ___________________________________________________________ Troubleshooting 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 on page 41.
USER'S GUIDE____________________________________________________________________ Technical Support For technical questions, contact the Vaisala technical support by e-mail at helpdesk@vaisala.com. Provide at least the following supporting information: - Name and model of the product in question Serial number of the product Name and location of the installation site Name and contact information of a technically competent person who can provide further information on the problem.
Chapter 7 ____________________________________________________________ Technical Data CHAPTER 7 TECHNICAL DATA This chapter provides the technical data of the DMT132. Specifications Performance Measured Variables Dewpoint temperature Measurement range Accuracy at +20 °C (+68 °F) -20 ... +50 °C (-4 ... +122 °F) Td ±1 °C for -3 ... 20 °C (+26.6 ... +68 °F) Td ±2 °C for -15 ... -3 °C (+5 ... +26.
USER'S GUIDE____________________________________________________________________ Calculated Variables Dewpoint converted to dewpoint in atmospheric pressure (Td/f atm). Operating Environment Temperature Operating Pressure Relative humidity Sample flow rate Measured gases -10 ... + 60 °C (+14 ... +140 °F) 0 ...
Chapter 7 ____________________________________________________________ Technical Data Output Cable Specifications Connector Color Number of contacts Conductors Insulation Cable diameter Protection class Wire color code Straight, moulded M8 female (IEC 60947-5-2) Black 4 0.25 mm² (× 4) / 0.00039 inch² (× 4) PVC 5.0 mm / 0.
USER'S GUIDE____________________________________________________________________ Dimensions in mm 125.5 80.5 45 6 12 2.5 36 G1/2" ISO 228-1 AW 30 5 33 R1 9. 1101-048 Figure 29 DMT132 Dimensions 40 20.
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