Vaisala HMP240 SERIES User Manual
  1. Manuals
  2. Brands
  3. Vaisala Manuals
  4. Transmitter
  5. HMP240 SERIES
  6. User manual
Vaisala HMP240 SERIES User Manual

Vaisala HMP240 SERIES User Manual

Hide thumbs
Table of Contents

Advertisement

Quick Links

HMP240 SERIES
TRANSMITTERS
User's Guide
M210300en-A
June 2002

Advertisement

Table of Contents
loading

Related Manuals for Vaisala HMP240 SERIES

Summary of Contents for Vaisala HMP240 SERIES

  • Page 1 HMP240 SERIES TRANSMITTERS User's Guide M210300en-A June 2002...
  • Page 2 Vaisala Oyj 2002 No part of this document 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 a prior written notice of the copyright holder.

  • Page 3: Table Of Contents

    HMP240 series M210300en User's guide Contents PRODUCT DESCRIPTION ..................5 ADVANTAGES OF A WARMED SENSOR HEAD ............7 INSTALLATION ......................8 Selecting the place of installation..............8 Mounting ......................9 3.2.1 Mounting the HMP243...............9 3.2.2 Mounting the HMP247..............11 Grounding ....................13 Electrical connections ................. 15 3.4.1...
  • Page 4 HMP240 series User's guide M210300en 5.4.2 Output via the serial bus ..............36 5.4.2.1 Starting the measurement output............ 36 5.4.2.2 Stopping the measurement output ..........36 5.4.2.3 Outputting the reading once............37 5.4.2.4 Setting the output interval for the RUN mode ........37 5.4.2.5...
  • Page 5 HMP240 series M210300en User's guide 7.5.2 With LED commands ..............60 Measurement of output currents using test points........60 Adjusting the contrast of the display............61 TECHNICAL DATA ....................62 Dewpoint temperature ................. 62 Temperature (with additional T sensor head)..........63 Calculated variables ..................
  • Page 6 HMP240 series User's guide M210300en This page intentionally left blank.

  • Page 7: Product Description

    HMP240 series M210300en User's Guide PRODUCT DESCRIPTION The HMP240 transmitter is a microprocessor based instrument for the measurement of dewpoint temperature especially in high humidities and/or fast changing temperatures. The dewpoint temperature is measured through relative humidity and temperature. The dewpoint temperature, although a calculated variable, is the primary reading obtained with the HMP240.
  • Page 8 HMP240 User's Guide M210300en Options Additional T probe For the measurement of the ambient temperature and for obtaining other quantities in addition to dewpoint temperature and mixing ratio Calculation vari- dewpoint difference, mixing ratio, absolute ables humidity, wet bulb temperature Serial interface RS 232C (standard), RS 485/422, digital current loop module...

  • Page 9: Advantages Of A Warmed Sensor Head

    Vaisala's HMP240 dewpoint transmitter offers a reliable solution for humidity measurement in all these demanding conditions. The humidity sensor head is kept dry by warming it.

  • Page 10: Installation

    HMP240 User's Guide M210300en INSTALLATION Selecting the place of installation The transmitter should be installed in a place that gives a true picture of the environment or process and is as clean as possible. Air should circulate freely around the sensor. If necessary, the transmitter can be installed in a place where a hot spot may develop.

  • Page 11: Mounting

    HMP240 series M210300en User's Guide Mounting 3.2.1 Mounting the HMP243 humidity sensor head T-sensor head (optional) ø6.5 Sliding PTFE-sleeve for flange installation Cable length 2000, and cable-gland installation 5000 or 10000 mm Figure 3.1 HMP243 transmitter with a humidity sensor head and an...
  • Page 12 HMP240-series User's Guide M210300en d u c t w a l l f l a n g e s e a l i n g ( s i l i c o n e ) h u m i d i t y s e n s o r h e a d a p l u g g e d h o l e f o r r e f e r e n c e s u p p o r t i n g b a r m e a s u r e m e n t s...

  • Page 13: Mounting The Hmp247

    Pressure tight installations A pressure tight installation can be done by using a probe head installation or cable installation. Vaisala's cable gland HMP247CG is recommended for the humidity probe's cable installation. The different pressure tight installations of the HMP247 are shown in the following pictures.
  • Page 14 HMP240 User's Guide M210300en Pressure tight installation with Vaisala's supportive thread bar set HMP247TBS (cable gland HMP247CG included) 1. Make a hole with M20x1.5 to a wall or weld a pipe fitting ( 30/M20x1.5x12mm) to a wall. 2. Install the cable gland's fitting body on the hole in the wall.

  • Page 15: Grounding

    HMP240 series M210300en User's Guide Grounding A single electrical cable with a screen and three to ten wires is recommended for power and analogue output/serial bus connections. The cable diameter should be 7...10 mm. The screen of the electrical cable must be grounded properly to achieve best possible EMC performance.
  • Page 16 HMP240 User's Guide M210300en tighten the nut connect the wires into the screw terminals and fasten a cable tie around the wires cable tie transmitter housing gland brass disks rubber ring NOTE When the cable is grounded as explained on the previous page, the metallic parts of the sensor head, the shield of its cable, the transmitter housing and the shield of the signal cable to external system are all...

  • Page 17: Electrical Connections

    HMP240 series M210300en User's Guide Electrical connections CH1- and CH2- are connected together internally CURRENT/VOLTAGE OUTPUTS POWER SUPPLY Do not use power supply ground (-) as output signal ground OPENED COVER OF THE HMP 243 Figure 3.6 Electrical connections Power supply 24 VDC 24 VAC (see Chapter 3.4.1)

  • Page 18: Connection To A 24 Vac Supply

    HMP240 User's Guide M210300en 3.4.1 Connection to a 24 VAC supply The HMP240 transmitter can also be connected to a 24 VAC supply without an external rectifier. However, when more than one transmitter is connected to one 24 VAC transformer, a common loop is formed and there is an increased risk of a short-circuit.

  • Page 19: Commissioning

    HMP240 series M210300en User's Guide COMMISSIONING When the HMP240 transmitter leaves the factory, its measurement ranges and output signals have already been scaled according to the order form completed by the customer. The unit is calibrated at the factory and ready to operate when the power is turned on.

  • Page 20: Selecting The Analogue Outputs

    When the security lock jumper is connected, some commands are not available (see Chapter 5). Should the application require variables that are not included in the configuration of the transmitter, the user is invited to contact Vaisala or a Vaisala representative. Selecting the analogue outputs The HMP240 transmitter can be ordered ready with the current or voltage outputs required.
  • Page 21 HMP240 series M210300en User's Guide CURRENT OUTPUTS 0 ... 20 / 4 ... 20 mA VOLTAGE OUTPUTS 0 ... 5 V / 0 ... 10 V VOLTAGE OUTPUTS 0 ... 1 V CH1 0 ... 1 VOLTAGE OUTPUT CH2 CURRENT OUTPUT OPENED COVER OF THE HMP 243 Figure 4.2...

  • Page 22: Connecting The Rs 232C Serial Bus

    HMP240 User's Guide M210300en spare jumpers OPENED COVER OF THE HMP 243 Figure 4.3 Spare jumpers Connecting the RS 232C serial bus OPENED COVER OF THE HMP 243 Figure 4.4 Serial bus connections To connect a PC to the HMP240 transmitter via the RS 232C serial bus, one of the following cables is required.
  • Page 23 HMP240 series M210300en User's Guide HMP 243 D25S TERMINAL D25P Figure 4.5 Connection of cables When the serial bus has been connected between the PC and the transmitter, the PC is switched on. When using a PC, a terminal emulation programme (e.g.

  • Page 24: Reverting To Factory Settings Of The Serial Port

    HMP240 User's Guide M210300en In calibrating or changing the settings of the transmitter it can be more con- venient to use the connector X17, if connector X6 is already in use. This con- nector, however, transfers only RS 232C signals. If an RS 485/422 serial port module or a current loop module has been installed, it has to be removed be- fore communicating through the X17 connector.
  • Page 25 HMP240 series M210300en User's Guide When the jumper is inserted the serial line factory settings become valid, but only temporarily. The transmitter must be given new settings; otherwise the transmitter uses the old, unknown settings after power-up. When the new settings have been given, the transmitter must be reset. The jumper must be removed before the transmitter is reset;...

  • Page 26: Commands

    HMP240 User's Guide M210300en COMMANDS As the HMP240 transmitter is a microprocessor based device, its configuration can be set to correspond to the specific needs of the user. This is done through commands, either by utilizing the menus on the local display or by giving commands through the serial interface (see Appendix 1).

  • Page 27: Led Commands

    HMP240 series M210300en User's Guide LED commands NOTE If the transmitter has a display/keypad cover, the LED commands cannot be used. LED commands can be used to operate the transmitter in the field. These commands can be used in humidity and temperature calibration and calibration of the analogue outputs.

  • Page 28: Display/Keypad Commands

    HMP240 User's Guide M210300en Display/keypad commands 5.3.1 Display mode In the display mode the transmitter outputs measurements on the display; dif- ferent quantities can be scrolled with arrow keys. The first line is scrolled with button and the second line with button ; all selections are stored with ENTER.

  • Page 29: Analogue Output Commands

    HMP240 series M210300en User's Guide 5.3.4 Analogue output commands 5.3.4.1 Selecting the output (mA/V) Disconnect the security lock jumper! Select Mode in the main menu and Analog outputs in the Mode menu: Select Mode ( mA / V ). The current settings for channel 1 are dis- played: If the settings are correct, press ENT.

  • Page 30: Selecting And Scaling The Analogue Output Quantities

    HMP240 User's Guide M210300en 5.3.4.2 Selecting and scaling the analogue output quantities Disconnect the security lock jumper! Select Mode in the main menu and Analog outputs in the Mode menu: Select Scale. The quantity and scaling for channel 1 are displayed: If the settings are correct, press ENT.

  • Page 31: Output Via The Serial Bus

    HMP240 series M210300en User's Guide 5.3.5 Output via the serial bus 5.3.5.1 Turning the serial interface echo ON/OFF Select More in the main menu, select More in the More menu and select Echo in the second More menu. Use the arrow keys to select the right alternative and press ENT.

  • Page 32: Setting The Transmitter Address

    HMP240 User's Guide M210300en Selecting stop bits: Full duplex/half duplex: The processor does not allow the following combinations: no parity, 7 data bits, 1 stop bit: if this combination is given the HMP240 programme will change the number of stop bits to 2 even or odd parity, 8 data bits, 2 stop bits: if this combination is given the programme changes the number of stop bits to 1 NOTE...

  • Page 33: Selecting The Output Units

    HMP240 series M210300en User's Guide 5.3.5.4 Selecting the output units Select Unit in the main menu: Use the arrow keys to select the right alternative and press ENT. metric non-metric °C °F °C °F gr/ft g/kg gr/lb °C °F 5.3.5.5...

  • Page 34: Setting The Serial Interface Operation Mode

    HMP240 User's Guide M210300en When the connection to a given transmitter is opened in the POLL mode, the transmitter goes into STOP mode and can then receive commands normally. Closing the connection returns the transmitter to POLL mode. In POLL mode, the transmitter outputs measurement only when requested (command SEND aa).

  • Page 35: Others

    HMP240 series M210300en User's Guide 5.3.7 Others 5.3.7.1 Setting the averaging time Disconnect the security lock jumper! With command FILT the transmitter can be given the averaging time during which the individual measurement samples are integrated to get an averaged reading.

  • Page 36: Setting The Date

    HMP240 User's Guide M210300en 5.3.7.3 Setting the date Select More in the main menu; select Date in the More menu: If the date is correct, acknowledge it by pressing ENT; this takes the programme back to the More menu. If the date needs to be changed, press CL. first the centuries (19) start flashing;...

  • Page 37: Heat On / Heat Off Command

    HMP240 series M210300en User's Guide 5.3.7.5 Heat on / heat off command The status of this command should always be HEAT ON, and it should not be altered. It is meant for service purposes only. Serial commands All available serial commands are described in more detail in Appendix 1. The following chapters include only the most commonly used command sequences.

  • Page 38: Selecting And Scaling The Analogue Output Quantities

    HMP240 User's Guide M210300en 5.4.1.2 Selecting and scaling the analogue output quantities Disconnect the security lock jumper! ASEL xxx yyy <cr> channel 1's quantity channel 2's quantity (RH, T, Td, dT, Abs, Mix or Tw) Example: RH selected on channel 1 and temperature on channel 2 >ASEL RH T <cr>...

  • Page 39: Outputting The Reading Once

    HMP240 series M210300en User's Guide 5.4.2.3 Outputting the reading once SEND <cr> in STOP mode SEND aa <cr> in POLL mode aa = address of the transmitter when more than one transmitter is connected to a serial bus (0...99) The output format depends on which parameters the transmitter can output.

  • Page 40: Selecting The Output Units

    HMP240 User's Guide M210300en changing parity only >SERI O <cr> 4800 O 7 1 HDX changing all parameters >SERI 600 N 8 1 F <cr> 600 N 8 1 FDX The processor does not allow the following combinations: no parity, 7 data bits, 1 stop bit: if this combination is given the HMP240 programme will change the number of stop bits to 2 even or odd parity, 8 data bits, 2 stop bits: if this combination is given the programme changes the number of stop bits to 1...

  • Page 41: Setting The Transmitter Address

    HMP240 series M210300en User's Guide The time can be set in seconds within the range of 0 - 1024 (0 = no averaging time). For example: >FILT Filter (S): 1024 > >FILT 100 <cr> Filter (S): > 5.4.2.8 Setting the transmitter address ADDR aa <cr>...

  • Page 42: Operating The Transmitter Via The Serial Bus

    HMP240 User's Guide M210300en 5.4.3 Operating the transmitter via the serial bus 5.4.3.1 Setting the serial interface SMODE xxxx<cr> xxxx STOP, RUN or POLL In STOP mode: measurements output only by command, all commands can be used In RUN mode: outputting automatically, only command S can be used In POLL mode: measurements output only with command SEND.

  • Page 43: Open & Close

    HMP240 series M210300en User's Guide 5.4.3.2 OPEN & CLOSE OPEN nn <cr> address of the transmitter (0...99) CLOSE <cr> In STOP mode: command OPEN has no effect, CLOSE sets the transmitter in POLL mode In POLL mode: command OPEN sets the transmitter temporarily in STOP...

  • Page 44: Calibration

    Humidity calibration The calibration of the HMP240 transmitter can be checked with a calibrated Vaisala humidity meter, e.g. the HM34. The HMI38 humidity data processor with an appropriate reference connection cable can be used as a field cali- brator. A two-point calibration can be done with the HMK15 or the HMK13B calibrator, or the instrument can be sent to Vaisala.

  • Page 45: One Point Humidity Calibration

    M210300en User's Guide 13.5 mm adapter must be used when calibrating with the HMK13B calibrator. The adapter (part no. 16611) can be ordered from Vaisala or Vaisala representatives. Calibration can be performed by giving the commands with the press switches inside the housing (see Chapter 5.2), through the serial bus (see Chapter 5.4)

  • Page 46: With Serial Commands

    HMP240 User's Guide M210300en 6.1.1.1 With serial commands Make sure that the sensors of the transmitter and the reference instrument are close to each other. Allow enough time for the sensor heads to stabilize to the measurement conditions Disconnect the security lock jumper! Give command CRH <cr>, enter the humidity value and press <cr>.

  • Page 47: With Led Commands

    HMP240 series M210300en User's Guide 6.1.1.3 With LED commands Make sure that the sensors of the transmitter and the reference instrument are close to each other. Allow enough time for the sensor heads to stabilize to the measurement conditions Disconnect the security lock jumper! Connect an ammeter/voltmeter to the analogue outputs (connector X2);...

  • Page 48: With Display / Keypad Commands

    HMP240 User's Guide M210300en Insert the sensor head into the measurement hole of the LiCl chamber. Wait at least 10 minutes for the reading to stabilize. Give command CRH <cr>, enter the first point value and press <cr>. >CRH <cr> RH : xx.x Ref1 ?

  • Page 49: With Led Commands

    HMP240 series M210300en User's Guide Insert the sensor head into the measurement hole of the NaCl chamber. Wait at least 20 minutes for the reading to stabilize. If necessary, change the second point reading with arrow keys and press ENT.

  • Page 50: Humidity Calibration Procedure After Sensor Change

    HMP240 User's Guide M210300en 6.1.3 Humidity calibration procedure after sensor change Humidity calibration should be performed in stable conditions using saturated salt solutions as a reference. If the transmitter has the re-gaining option, the re-gaining has to be done manually before starting the calibration. 6.1.3.1 With serial commands Leave the calibrator and the transmitter for at least 4 hours...

  • Page 51: With Led Commands

    HMP240 series M210300en User's Guide Insert the sensor head into the measurement hole of the LiCl chamber. Wait at least 20 minutes for the reading to stabilize. Select Cali in the main menu and then RH cal; select Sen- sor changed. Change the first point reading with the ar- row keys and press ENT.

  • Page 52: Humidity Calibration Table

    HMP240 User's Guide M210300en The basic capacitance of the new sensor may differ considerably from that of the previous one. Therefore the corresponding humidity reading of the transmitter may be below 0 %RH at the low or above 100 %RH at the high calibration point.

  • Page 53: One Point Offset Calibration

    HMP240 series M210300en User's Guide 6.2.1 One point offset calibration 6.2.1.1 With serial commands Leave the reference instrument and the transmitter for at least 4 hours in the same space so that their temperatures have time to equalize. Remove the filter cap prior to calibration.

  • Page 54: Two Point Temperature Calibration

    HMP240 User's Guide M210300en 6.2.2 Two point temperature calibration 6.2.2.1 With serial commands Leave the reference instrument and the transmitter for at least 4 hours in the same space so that their temperatures have time to equalize. Remove the filter cap prior to calibration.

  • Page 55: With Display / Keypad Commands

    HMP240 series M210300en User's Guide 6.2.2.2 With display / keypad commands Leave the reference instrument and the transmitter for at least 4 hours in the same space so that their temperatures have time to equalize. Remove the filter cap prior to calibration.

  • Page 56: Calibration Of Analogue Outputs

    HMP240 User's Guide M210300en Calibration of analogue outputs The analogue outputs have been calibrated at the factory and since they are very stable, calibration should be performed only when there is reason to believe that their adjustments have changed. 6.3.1 With serial commands Disconnect the security lock jumper! ACAL <cr>...

  • Page 57: With Led Commands

    HMP240 series M210300en User's Guide Enter the measured upper end current/voltage on channel 2. 6.3.3 With LED commands If both the analogue outputs and humidity/temperature channels are calibrated, the analogue outputs should be calibrated first. This applies only when the...

  • Page 58: Maintenance

    If errors or faults are found, first check whether the humidity and temperature sensors are damaged. If they are intact, send the transmitter to Vaisala or a Vaisala representative for repairs. The error messages the transmitter outputs are listed in Appendix 4.

  • Page 59: Replacing The Composite Sensor

    HMP240 series M210300en User's Guide > When errors have occurred, the transmitter outputs an error code (see Appen- dix 4 for all error messages): >ERRS <cr> ( all ) out of range > Replacing the composite sensor The humidity and temperature sensors (HUMICAP H-sensor and Pt100) have been glued together.

  • Page 60: With Serial Commands

    HMP240 User's Guide M210300en Figure 7.1 Location of solder lugs TP1, TP2 and TP3 and connector Connect a Pt 100 simulator to connector X77 and set it at the lowest tempera- ture to be calibrated. Pt 100 Figure 7.2 Connecting the Pt 100 simulator to connector X77 Switch the power on.

  • Page 61: Temperature Channel Adjustment With Pt 100 Simulators (Composite Sensor)

    HMP240 series M210300en User's Guide Disconnect the Pt 100 simulator and reconnect the Pt 100 wires to solder lugs TP1, TP2 and TP3. The correct connections according to wire colours are: blue white If a Pt 100 simulator is not available, the adjustment can be made with two...

  • Page 62: With Serial Commands

    HMP240 User's Guide M210300en Pt 100 Figure 7.4 Connecting the Pt 100 simulator to connector X88 Switch the power on. 7.5.1.1 With serial commands Give command CT, enter the first point value and press <cr>: >CT <cr> xx.x Ref1 ? yy.y <cr>...

  • Page 63: Adjusting The Contrast Of The Display

    HMP240 series M210300en User's Guide the external load. The output current can, however, be measured at test points CH1+/CH1- and CH2+/CH2- without disconnecting the output wires. These test points can therefore be used in one point offset correction against an accu- rate reference or in checking the current output without disconnecting the analogue output from the process.

  • Page 64: Technical Data

    HMP240 User's Guide M210300en TECHNICAL DATA Sensor RH & T composite sensor HUMICAP ® KC(part no. 18258HM) T sensor in the humidity sensor head Pt 100 IEC 751 class 1/3 B Voltage proof, AC: DC supply (+ or -) to housing 250 VAC, 1 minute (300 k and 15 nF parallel) Dewpoint temperature...

  • Page 65: Temperature (With Additional T Sensor Head)

    HMP240 series M210300en User's Guide Temperature (with additional T sensor head) Measurement range -40...+180 °C Typical accuracy at +20 C (+68 F) ±0.1 °C Typical temperature dependence of electronics 0.005 °C/°C Temperature sensor Pt 100 RTD DIN IEC 751, class 1/4 B...

  • Page 66: Accuracy Of Other Calculated Variables

    HMP240 User's Guide M210300en 8.3.2 Accuracy of other calculated variables Accuracy of mixing ratio (g/kg) when ambient pressure is 1013 mbar Relative humidity Temp. 0.001 0.002 0.002 0.002 0.003 0.003 0.007 0.010 0.012 0.014 0.017 0.019 0.021 0.024 0.033 0.043 0.053 0.063 0.074...

  • Page 67: Outputs

    HMP240 series M210300en User's Guide Outputs Two analogue outputs selectable 0...20 mA 4...20 mA 0...1 V 0...5 V 0...10 V Typical accuracy of an analogue output at +20 °C ±0.05 % full scale Typical temperature dependence of an analogue output 0.005 %/°C full scale...

  • Page 68: Mechanics

    HMP240 User's Guide M210300en Operating temperature (electronics) -40...+60 °C with display cover 0...+50 °C Storage temperature -40...+70 °C Mechanics Housing material G-AlSi12 (DIN 1725) Housing classification IP 65 (NEMA 4) Bushing for 7...10 mm diameter cable (8 x 0.5 mm shielded cable) Sensor protection stainless steel sintered filter...

  • Page 69: Electromagnetic Compatibility

    HMP240 series M210300en User's Guide Figure 8.4 HMP247 sensor head information Weight with 2 m cable 5 m cable 10 m cable HMP240 (duct mounting, max 1100 g 1300 g 1500 g 180 C, without T probe) T probe for HMP240...

  • Page 70: Spare Parts And Accessories

    HMP240 User's Guide M210300en SPARE PARTS AND ACCESSORIES Order code Description HMP243FA Mounting kit for HMP240, +180 °C cable 16452 Sintered filter, stainless steel 16720 PPS grid with stainless steel netting ® HUMICAP Composite humidity and temperature sensor 16611 Calibration adapter for the HMK13B Calibrator HMP240RS RS 485/422 serial module HMP247CG...

  • Page 71: Appendix 1: Serial Commands

    HMP240 M210300en Appendix 1: Serial commands APPENDIX 1: SERIAL COMMANDS ANALOGUE OUTPUT COMMANDS ................. 70 CALIBRATION COMMANDS ..................73 OUTPUT VIA THE SERIAL BUS ................77 Operation modes..................84 OTHERS ........................86 The commands function as described when the serial interface is in full- duplex mode and echo is on.

  • Page 72: Analogue Output Commands

    HMP240 Appendix 1: Serial commands M210300en ANALOGUE OUTPUT COMMANDS AMODE Setting the analogue outputs Disconnect the security lock jumper! AMODE a bb.bbb cc.ccc d ee.eee ff.fff <cr> channel 1: voltage output current output bb.bbb = lower limit of channel 1 cc.ccc = upper limit of channel 1 channel 2:...
  • Page 73 HMP240 M210300en Appendix 1: Serial commands For example, relative humidity is selected to be output on channel 1 and tem- perature on channel 2; the temperature range is scaled to 0...100 C: >ASEL RH T <cr> Ch1 (RH) 0.000 %RH ? <cr>...
  • Page 74 HMP240 Appendix 1: Serial commands M210300en The output scales can also be given directly with the ASCL command. ASCL aaa.a bbb.b ccc.c ddd.d <cr> aaa.a lower limit of channel 1 bbb.b upper limit of channel 1 ccc.c lower limit of channel 2 ddd.d upper limit of channel 2 For example, when relative humidity is scaled to 0...100 %RH on channel 1...

  • Page 75: Calibration Commands

    HMP240 M210300en Appendix 1: Serial commands CALIBRATION COMMANDS Relative humidity calibration Disconnect the security lock jumper! CRH <cr> With this command the transmitter can be calibrated against a reference. A one-point calibration can be done against an accurate transfer standard in the field and a two-point calibration using saturated salt solutions in controlled conditions.
  • Page 76 HMP240 Appendix 1: Serial commands M210300en The command can also be divided into two commands, so the computer can be used for other purposes while waiting for the sensor to stabilize to the higher humidity. >FCRH 1 <cr> 1.90 Ref1 ? 11.3 <cr>...
  • Page 77 HMP240 M210300en Appendix 1: Serial commands Temperature calibration of the optional T sensor head Disconnect the security lock jumper! CTA <cr> With this command the optional temperature sensor head can be calibrated against an accurate reference, such as a Pt 100 simulator. A two-point calibration is performed as follows: >CTA <cr>...
  • Page 78 HMP240 Appendix 1: Serial commands M210300en Outputting linear correction coefficients L <cr> With the help of command L the user can check how the transmitter has been adjusted after it has been calibrated at the factory. >L <cr> offset : 0.000 gain : 1.000 offset...

  • Page 79: Output Via The Serial Bus

    HMP240 M210300en Appendix 1: Serial commands OUTPUT VIA THE SERIAL BUS Starting the measurement output R <cr> Starts output of measurements to the peripheral devices (PC display or printer); output interval is set with command INTV. The output format depends on the transmitter configuration and variables used. The sequence, however, is always the same: relative humidity, temperature, dewpoint temperature, absolute humidity, mixing ratio, wet bulb temperature and dewpoint difference.
  • Page 80 HMP240 Appendix 1: Serial commands M210300en DSEND Outputting readings of all connected transmitters once DSEND <cr> All transmitters connected to the serial bus send their addresses and current measurement readings in a sequence defined by their addresses. After receiving DSEND command a transmitter sets a delay time according to its address value and sends the data after this delay.
  • Page 81 HMP240 M210300en Appendix 1: Serial commands ECHO Turning the serial interface echo ON/OFF ECHO xxx <cr> ON or OFF When the echo is off, the commands given through the serial interface or the prompt > cannot be seen on the display. When the serial interface is in half-duplex mode, the echo is always off.
  • Page 82 HMP240 Appendix 1: Serial commands M210300en FORM Setting the output format FORM <cr> "xxx...xxx" ? zzz...zzz <cr> xxx...xxx old format zzz...zzz new format The FORM command sets the format of the outputs generated in RUN state and by SEND command. Please note that capital and small letters have dif- ferent meanings.
  • Page 83 HMP240 M210300en Appendix 1: Serial commands ?\UUU.U\\t\TTT.T\\t\DDD.D\\t\AAA.A\\t\XXX.X\\t\WWW.W\\ r\n <cr> The output is then: 47.4<tab> 22.4 <tab> 10.6 <tab> 9.4 <tab> 8.0 <tab> 15.4 <cr><lf> FTIME Adding time to output FTIME xxx <cr> ON or OFF When FTIME is activated, the current time is output at the beginning of the output line.
  • Page 84 HMP240 Appendix 1: Serial commands M210300en Activating the date output >fdate on Form. date >r 1995-03-10 RH= 21.1 %RH T= 26.0 'C 1995-03-10 RH= 21.3 %RH T= 26.0 'C 1995-03-10 RH= 23.1 %RH T= 26.0 'C 1995-03-10 RH= 22.2 %RH T= 26.0 'C 1995-03-10 RH= 20.6 %RH T= 26.0 'C Inactivating the date output >fdate off...
  • Page 85 HMP240 M210300en Appendix 1: Serial commands The processor does not allow the following combinations: no parity, 7 data bits, 1 stop bit: if this combination is given the HMP240 programme will change the number of stop bits to 2 even or odd parity, 8 data bits, 2 stop bits: if this combination is given the programme changes the number of stop bits to 1 When the half-duplex mode is set, it will automatically turn the echo off.

  • Page 86: Operation Modes

    HMP240 Appendix 1: Serial commands M210300en When asking the current address, no address number is given: >ADDR <cr> Address 2 ? <cr> FROST Setting the calculation mode Disconnect the security lock jumper! FROST ON/OFF <cr> This command is used to select whether the transmitter calculates the frostpoint (default) or the dewpoint reading at dewpoint temperatures below C.
  • Page 87 HMP240 M210300en Appendix 1: Serial commands SMODE xxxx<cr> address of the transmitter xxxx STOP, RUN or POLL The OPEN command sets the bus temporarily in STOP MODE so that the SMODE command can be given. For example: which mode is in use at the moment >SMODE <cr>...

  • Page 88: Others

    HMP240 Appendix 1: Serial commands M210300en OTHERS ITEST Testing the analogue outputs ITEST <cr> ITEST a b <cr> current/voltage of channel 1 current/voltage of channel 2 The operation of the analogue outputs can be tested by forcing the outputs to given values which can then be measured with a current/voltage meter from the analogue outputs.
  • Page 89 HMP240 M210300en Appendix 1: Serial commands The time can be set in seconds within the range of 0 - 1024 (0 = no averaging time). For example: >FILT <cr> Filter (S): 1024 > >FILT 100 <cr> Filter (S): > PRES Setting the pressure for mixing ratio and wet bulb temperature calculations PRES pppp.pp <cr>...
  • Page 90 HMP240 Appendix 1: Serial commands M210300en XPRES Setting the pressure for mixing ratio and wet bulb temperature calculations temporarily XPRES pppp.pp <cr> pppp.pp = pressure (hPa) The function and format of XPRES are the same as those of the PRES com- mand except that by using XPRES the setting is valid only until a reset is given or power is turned off or pressure is set to zero using XPRES.

  • Page 91: Vers Name And Version Of The Programme

    HMP240 M210300en Appendix 1: Serial commands TIME <cr> For example, to enter a new time: >TIME <cr> Current time is 01:35:54 Enter new time (hh:mm:ss) : 13:25:56 <cr> When the current time is asked, the new time is passed with <cr>. VERS Name and version of the programme VERS <cr>...
  • Page 92 HMP240 Appendix 1: Serial commands M210300en ?? <cr> Command ?? outputs the same information as command ? but it works also when the transmitter has been set to POLL mode. However, if there are more than one addressed transmitters connected to the serial bus, they all will re- spond at the same time and the output on the screen will be chaotic.

  • Page 93: Appendix 2: Installing And Using The Rs 485/422 Serial Port Module

    HMP240 M210300en Appendix 2: RS 485/422 serial port module APPENDIX 2: INSTALLING AND USING THE RS 485/422 SERIAL PORT MODULE INSTALLATION ......................92 OPERATION ......................93 NETWORK CONFIGURATION.................. 95 3.1. Single loop operation................... 95 3.2. Dual loop operation ..................97 CHECKING THE SERIAL PORT NETWORK OPERATION ........

  • Page 94: Installation

    HMP240 Appendix 2: RS 485/422 serial port module M210300en 1. INSTALLATION Switch the transmitter off. Resistors R2, R3 and R4 between connectors X4 and X5 in the component board in the cover of the transmitter are removed with side-cutting pliers. The module is plugged in connectors X4 and X5 on the main board of the HMP240 transmitter;...

  • Page 95: Operation

    HMP240 M210300en Appendix 2: RS 485/422 serial port module OPERATION The HMP240 transmitter can either be given an address or operated without an address. Both single and dual loop wiring with half duplex connection can be used. No address is needed when only one HMP240 transmitter is used; when several transmitters are connected to the same line, each transmitter must be given an address in the initial configuration.
  • Page 96 HMP240 Appendix 2: RS 485/422 serial port module M210300en The RS 485/422 module has separate lines for transmitting and receiving, but they can be connected together with jumpers. Dual loop connection is the factory setting; when a single loop connection is used, the positions of jump- ers in connector X4 on the module must be changed.

  • Page 97: Network Configuration

    HMP240 M210300en Appendix 2: RS 485/422 serial port module NETWORK CONFIGURATION Single loop operation Bi-directional data on one pair is one of the great advantages of the RS 485 line. Set jumpers in connector X4 on the module board as shown in the figure below.
  • Page 98 HMP240 Appendix 2: RS 485/422 serial port module M210300en Set the address of the transmitter; you can choose any number between 1 and 99. In this example the address is 22: >addr 22 Address Set the serial bus settings according to your network specifications. This setting will become valid after next RESET or power off: >seri 2400 e 7 1 h 2400 E 7 1 HDX...

  • Page 99: Dual Loop Operation

    HMP240 M210300en Appendix 2: RS 485/422 serial port module Dual loop operation The following procedure must be repeated with all transmitters. Open the transmitter cover. Pull out the RS 485/422 serial port module, if it is already mounted. Set the serial port of the terminal to 4800 baud, even parity, seven data bits and one stop bit, full duplex (4800 E 7 1 FDX).
  • Page 100 HMP240 Appendix 2: RS 485/422 serial port module M210300en NOTE 2 The transmitter outputs no prompt (>) after the SMODE POLL command and it only reacts to commands which include its address. Check that the transmitter responds to its address: >send 22 RH= 24.4 %RH T= 29.1 'C Disconnect the terminal.

  • Page 101: Checking The Serial Port Network Operation

    HMP240 M210300en Appendix 2: RS 485/422 serial port module CHECKING THE SERIAL PORT NETWORK OPERATION Measurement readings are normally asked with the transmitter in POLL mode; the command must include the address of the transmitter. If the settings of the transmitter need to be changed, the transmitter is switched to STOP mode with command OPEN;...

  • Page 102: Poll Mode

    HMP240 Appendix 2: RS 485/422 serial port module M210300en POLL mode If a transmitter has been set to POLL mode, it will respond only to commands sent with its address: send 22 RH= 24.4 %RH T= 29.1 'C Addresses from 1 to 99 can be used. According to the RS 485/422 standard a maximum of 32 devices can be connected on same bus, but the number can be increased if the line length and/or baud rate is reduced.

  • Page 103: Specifications

    HMP240 M210300en Appendix 2: RS 485/422 serial port module SPECIFICATIONS Connections Berg sockets on the main board screw terminals 0.5 mm² wires, stranded wires recommended Assembly plug-in module Board dimensions 40 x 28 mm Operating mode half duplex (single or dual pair wiring) Network: network type daisy chain...

  • Page 104: Appendix 3: Installing And Using The Digital Current Loop Module

    HMP240 Appendix 3: Digital current loop module M210300en APPENDIX 3: INSTALLING AND USING THE DIGITAL CURRENT LOOP MODULE INSTALLATION Switch the transmitter off. Resistors R2, R3 and R4 between connectors X4 and X5 in the component board in the cover of the transmitter are removed with side-cutting pliers. The module is plugged in connectors X4 and X5 on the main board of the HMP240 transmitter;...
  • Page 105 HMP240 M210300en Appendix 3: Digital current loop module Unregulated AC/DC adapter can be used, if the current is limited to 20 mA at least by a serial resistor. Note.The host computer can restrict the loop supply voltage that can be used; see computer specifications.
  • Page 106 HMP240 Appendix 3: Digital current loop module M210300en incorrectly, the voltage drop from RX+ to RX- or from TX+ to TX- is below 1 V and the transmitter does not work. Even then the current goes through the loop and the other transmitters can be operated normally. When the loop supply is current limited, the data lines can withstand short cir- cuit to ground and to each other.
  • Page 107 HMP240 M210300en Appendix 3: Digital current loop module Single loop wiring Set the address of the transmitter; you can choose any number between 1 and 99. In this example the address is 22: >addr 22 Address Set the serial bus settings according to your network specifications. This setting will become valid after next RESET or power off: >seri 2400 e 7 1 h 2400 E 7 1 HDX...
  • Page 108 HMP240 Appendix 3: Digital current loop module M210300en Set the serial port of the terminal to 4800 baud, even parity, seven data bits and one stop bit, full duplex (4800 E 7 1 FDX). The serial settings of the transmitter must also be 4800 E 7 1 FDX and the transmitter must be in STOP mode.
  • Page 109 HMP240 M210300en Appendix 3: Digital current loop module >send 22 RH= 24.4 %RH T= 29.1 'C Disconnect the terminal. Remount the digital current loop module. Close the cover. Repeat this setting procedure with each transmitter When all transmitters on the network have been configured, switch them off.
  • Page 110 HMP240 Appendix 3: Digital current loop module M210300en 180.000 'C Transducer PRB serial nr : Calibr. date When the necessary settings have been given, close the line to transmitters (the command closes all open lines): >close line closed CLOSE command is always given without address. If no line is open, there will be no response to the CLOSE commands.
  • Page 111 HMP240 M210300en Appendix 3: Digital current loop module Specifications Galvanic isolation 1500 VAC/DC max. (1 min) Loop supply voltage 40 V max. Loop supply current 20 mA nominal must be current limited Operating loop voltage requirement 4 V/each transmitter (TX+/TX-) on the loop 2 V/each receiver (RX+/RX-) on the loop...

  • Page 112: Appendix 4: Error Messages

    HMP240 Appendix 6: HMP243 wiring diagram M210300en APPENDIX 4: ERROR MESSAGES Errors after reset ..................112 Errors during operation................113...
  • Page 113 Display Serial bus E11 CPU EEPROM ackn. error - the CPU hybrid is probably damaged. Send the transmitter to Vaisala for repair. E12 CPU EEPROM checksum error - possibly due to an electrical disturbance an erroneous parameter value or an incorrect checksum has been stored in the EEPROM.
  • Page 114 Appendix 6: HMP243 wiring diagram M210300en E21 PRB EEPROM ackn. error - no connection to the EEPROM including calibration information can be formed. Send the transmitter to Vaisala for repair. E22 PRB EEPROM checksum error ackn. error EEPROM is faulty...
  • Page 115 Check the temperature measurement wires and their solderings on the component board (TP5,TP6,TP7 and TP8). If you cannot find any faults, send the transmitter to Vaisala for repair. E43 f (Rk1 ) out of range - the temperature measurement cannot be completed. Check the temperature sensor and its solderings.
  • Page 116 (TP9,TP10 and TP11/15). If you cannot find any faults, send the transmitter to Vaisala for repair. E46 f (Ud2 ) out of range - the measurement hybrid is probably damaged. Send the transmitter to Vaisala for repair.
  • Page 117 (TP9,TP10 and TP11/15). If you cannot find any faults, send the transmitter to Vaisala for repair. E54 U2 y-value out of range - the measurement hybrid is probably damaged. Send the transmitter to Vaisala for repair.

  • Page 118: Appendix 5: Calculation Formulas

    HMP240 Appendix 6: HMP243 wiring diagram M210300en APPENDIX 5: CALCULATION FORMULAS The HMP240 transmitter measures relative humidity and temperature. From these values dewpoint, mixing ratio and absolute humidity are calculated using the following equations: dewpoint: mixing ratio: 621 98 p RH P absolute humidity: 216 68 273 2...
  • Page 119 HMP240 M210300en Appendix 5: Calculation formulas where: = coefficients b -1 = -0.58002206 * 10 4 = 0.13914993 * 10 1 = -0.48640239 * 10 -1 = 0.41764768 * 10 -4 = -0.14452093 * 10 -7 = 6.5459673 The parameters A, m, and T depend on temperature according to the follow- ing table: 0 ...

  • Page 120: Appendix 6: Hmp240 Wiring Diagram

    HMP240 Appendix 6: HMP243 wiring diagram M210300en APPENDIX 6: HMP240 WIRING DIAGRAM Appendix 6: HMP243 wiring diagram Ch a n g e Re a s o n / ECO n o De s i g n Da t e Re v i e w Dat e Appr Qt y Lt r...

  • Page 121: Appendix 7: Re-Gaining

    HMP243 M210300en Appendix 7: Re-gaining APPENDIX 7: RE-GAINING GENERAL ....................... 120 TO BE NOTED IN RE-GAINING................121 LED COMMANDS ....................122 DISPLAY/KEYPAD COMMANDS ................123 4.1. Re-gaining parameters................123 4.2. Starting re-gaining manually ..............124 SERIAL COMMANDS ..................... 125 Re-gaining settings ..............125 Re-gaining parameters..............

  • Page 122: General

    HMP240 Appendix 7: Re-gaining M210300en GENERAL In some specific applications the sensor gain may decrease gradually due to an interference caused by some particular chemical present in the ambient (see figure 1). The sensor polymer absorbs the interfering chemical; this reduces the polymer's ability to absorb water molecules and so decreases the sensor gain.

  • Page 123: To Be Noted In Re-Gaining

    HMP243 M210300en Appendix 7: Re-gaining TO BE NOTED IN RE-GAINING Re-gaining cannot be started automatically or manually unless the security lock jumper is on. This prevents automatic re-gaining during a sensor calibration (when the security lock jumper must be removed). Furthermore, re-gaining can be started only if the sensor temperature is below 100 °C.

  • Page 124: Led Commands

    HMP240 Appendix 7: Re-gaining M210300en LED COMMANDS Re-gaining can be started manually using the LED command ll¡¡ (l = lit, ¡ = dark). Use the up and down press switches (marked with arrows in the printed board) to find the command code and acknowledge it with the ENT switch.

  • Page 125: Display/Keypad Commands

    HMP243 M210300en Appendix 7: Re-gaining DISPLAY/KEYPAD COMMANDS Disconnect the security lock jumper! Press the CL key to enter the command mode. Select More from the first menu using the arrow keys and press ENT key. Select again More from the second menu and press ENT.

  • Page 126: Starting Re-Gaining Manually

    HMP240 Appendix 7: Re-gaining M210300en Use arrow keys to change the status of the automatic re-gaining and press ENT. Acknowledge the current setting by pressing ENT. To change the interval press CL. Select the new time interval digit by digit with the arrow keys and acknowledge each digit with ENT key.

  • Page 127: Serial Commands

    HMP243 M210300en Appendix 7: Re-gaining SERIAL COMMANDS 1.2.1 REG Re-gaining settings REG <cr> REG nnn <cr> nnn = ON or OFF Command REG is used to check the re-gaining parameter settings and to activate or inactivate the automatic re-gaining. Examples: checking the current settings >reg automatic re-gaining is inactive REG OFF...

  • Page 128: Cri Changing Re-Gaining Parameters

    HMP240 Appendix 7: Re-gaining M210300en 1.2.3 CRI Changing re-gaining parameters CRI <cr> With command CRI the values of the re-gaining parameters can be changed. Example: changing the re-gaining interval to 480 min and the settling time after sensor heating to 360 s >cri Interval min :...

  • Page 129: Regen Starting Re-Gaining Manually

    HMP243 M210300en Appendix 7: Re-gaining Example: activating status display >fst on Form. status >r N = re-gaining off 0 RH= 20.8 %RH T= 25.6 'C 0 RH= 20.7 %RH T= 25.6 'C 0 RH= 20.7 %RH T= 25.6 'C 0 RH= 20.8 %RH T= 25.6 'C H = heating on, 163 163 RH= 20.8 %RH T= 25.6 'C describes the heating...
  • Page 130 HMP240 Appendix 7: Re-gaining M210300en Example: >regen Regeneration started, press any key to abort >r heating is finished, 162 RH= 20.0 %RH T= 26.5 'C settling time is on and 162 RH= 20.0 %RH T= 26.5 'C outputs are locked 162 RH= 20.0 %RH T= 26.5 'C settling time is over and 162 RH= 18.4 %RH T= 27.7 'C...

This manual is also suitable for:

Hmp243Hmp247

Table of Contents