Vaisala HMP140 User Manual

USER'S GUIDE

Vaisala HUMICAP® Humidity

Transmitter Series

HMP140A

U175EN15

PUBLISHED BY
Vaisala Oyj Phone (int.): [phone]

P.O. Box 26 Fax: [phone]
FIN-00421 Helsinki
Finland

Visit our Internet pages at http://www.vaisala.com/

© Vaisala 2006
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.

Please observe that this manual does not create any legally binding obligations for
Vaisala towards the customer or end user. All legally binding commitments and
agreements are included exclusively in the applicable supply contract or Conditions of
Sale.

HMP140A SERIES

U175en-1.5 Operating Manual

Contents

1. PRODUCT DESCRIPTION ...................................................................................................1

2. TO BE NOTED WHEN M EASURING HUMIDITY ..................................................................2

3. INSTALLATION....................................................................................................................3

3.1 Selecting the place of installation ..........................................................................3

3.2 Mounting..................................................................................................................3

3.2.1 Mounting the HMP141A .............................................................................4

3.2.2 Mounting the HMP142A .............................................................................4

3.2.3 Mounting the HMP143A .............................................................................5

3.3 Electrical connections.............................................................................................6

3.4 Connectors and potentiometers on the main PCB................................................7

3.5 Selecting the outputs..............................................................................................7

3.6 Connection to an AC supply..................................................................................8

4. CALIBRATION .....................................................................................................................9

4.1 One-point humidity calibration...............................................................................9

4.2 Two-point humidity calibration...............................................................................9

4.2.1 Two-point humidity calibration procedure ...................................................9

4.3 Temperature calibration........................................................................................10

4.4 Calibration table.................................................................................................... 11

5. MAINTENANCE..................................................................................................................11



5.1 Replacing the HUMICAP

6. TECHNICAL DATA.............................................................................................................12

6.1 Relative humidity...................................................................................................12

6.2 Temperature...........................................................................................................12

6.3 General...................................................................................................................13

6.4 Electromagnetic compatibility..............................................................................14

6.4.1 Emissions................................................................................................14

6.4.2 Interference.............................................................................................14

7. SPARE PARTS AND ACCESSORIES ................................................................................14

180 sensor and the filter ............................................11

APPENDIX 1: CURRENT OUTPUT MODULE

APPENDIX 2: SETTINGS OF THE LOCAL DISPLAY

APPENDIX 3: HMP143A PROBE CABLE EXTENSION

TECHNICAL DATA

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1. PRODUCT DESCRIPTION

The HMP140A series transmitters are reliable and easy to use instruments for
the measurement of relative humidity and temperature. The series consists of
three different types of transmitters to be chosen according to the requirements
of the application:

• HMP141A for wall installations

• HMP142A for duct installations

• HMP143A for installation in tight places

The configuration can be chosen from various possibilities to meet the specific
requirements of the customer. The transmitters can be ordered with a blank
cover or a cover with a local display which outputs relative humidity and
temperature readings. The reading to be displayed is chosen with a pushbutton
on the cover and the desired temperature unit (Celsius or Fahrenheit) can be
chosen with a jumper (see Appendix 2).

All HMP140A transmitters measure relative humidity in the range of

0...100 %RH and temperature from -40 to +60 °C; the measurement is
temperature compensated. The HMP140A transmitters have four different
analogue outputs: 0...20 mA (4...20 mA), 0...1 V, 0...5 V and 0...10 V. The
outputs are also scalable if necessary, e.g. 4...20 mA from 0...20 mA.

The durable plastic cover provides IP65 protection from dust and sprayed
water. The HMP140A transmitters are therefore suitable for most indoor and
outdoor applications, including those with high humidities like indoor
swimming pools etc. These versatile transmitters are also easy to install and to
use. When necessary, they can be recalibrated on site with Vaisala’s HMI41
indicator equipped with an appropriate probe and optional calibration cable
(19116ZZ).

The HMP140A series transmitters incorporate the HUMICAP180 sensor, the
operation of which is based on the changes in its capacitance as the thin
polymer film absorbs water molecules. The sensor is immune to most
chemicals and has an excellent long-term stability. The temperature is
measured with a Pt 1000 sensor.

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2. TO BE NOTED WHEN MEASURING HUMIDITY

In the measurement of humidity and especially in calibration, it is essential
that the temperature equilibrium is reached. Even a slight difference in the
temperature between the measured object and the sensor causes an error. For
example, at +20 °C (+ 68 °F) and 50 %RH, a temperature difference of +1 °C
between the measured object and the sensor causes an error of +3 %RH. If
relative humidity is 90 %RH, the error is about +5.4 %RH.

The error is at its greatest when the temperature of the sensor differs from that
of the surroundings and the humidity is high. A few degrees’ difference in
temperature may cause water to condense on sensor surface. Efficient
ventilation accelerates evaporation whereas in an unventilated space, it may

take hours. The HUMICAP180 sensor returns to its normal functioning as
soon as water has evaporated. Any contaminated water condensing on the
sensor may shorten its life span and change the calibration.

10

9
8
7
6
5
4

dRH (%RH)

3
2
1
0

-40-200 20406080100
Temperature (°C)

Figure 2.1 Measurement error at 100 %RH when the temperature

difference between th e ambient and the sensor i s 1 °C

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3. INSTALLATION

3.1 Selecting the place of installation

Select 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. A rapid air
flow is recommended as it ensures the same temperature for the ambient air
and the sensor head.

Install the transmitter in a place where no cold or hot spot can develop. If the
sensor head is installed in a duct or channel where the temperature is different
from the ambient temperature, insulate the point of entry; this is particularly
important if the transmitter is installed with the sensor head pointing
downwards. Vertical installation of the HMP142A and HMP143A is not
recommended; they should be mounted with the sensor head horizontally
whenever possible. An uninsulated installation might lead to condensation on
the sensor head and even if no condensation occurs, the resultant air flow may
change the temperature near the sensor head and distort the readings.

3.2 Mounting

The electronics of the HMP140A series can be disconnected for ease of
installation and service. The housing can be conveniently installed and the
electronics then consequently mounted. For service and maintenance purposes
the electronics can be disconnected without disconnecting the cabling, and
taken to an appropriate environment for necessary adjustments.

60

6.5

60

83.5

4.2

Figure 3 Drilling dimensions (in mm)

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3.2.1 Mounting the HMP141A

The optimal installation of the HMP141A is with the sensor head pointing
downwards. Upward mounting should be avoided due to internal heat transfer.

1. Mounting and wiring:
cable feedthrough
on the surface or
in the connection box.

2. Mount the protection
lid to the conn ection
box.

3. Push the s e nsor h ea d
through the protection
lid a s in fig ure a n d
connect the electronics
housing to the connection
box. Make sure that the
pins at the bottom of
the electronics housing
are in co nt ac t with the
sc r ew termin a l .

4. Fasten the four
conn ec ting s cre w s of
the electronics housing.

5. Place the sensor head
into the p ro t e ct io n lid .

6. Close the cover and fasten
the two co n ne c tion s c rews.

1

3

4

4

6

4

4

5

2

Figure 3.2.1 Mounting of the HMP141A

3.2.2 Mounting the HMP142A

The HMP142A transmitter should be mounted with the sensor head
horizontally whenever possible. This way, any water that might condense on
the tube cannot flow on to the sensors. When there is no alternative but to
install the sensor head in the process vertically, the point of entry must be
carefully insulated.

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U175en-1.5 Operating Manual

225

Ø 15

Ø 12

Figure 3.2.2 Dimensions of the HMP142A (in mm)

3.2.3 Mounting the HMP143A

The cable model HMP143A should also be mounted with the sensor head
horizontally whenever possible. This model is provided with two plastic nuts
and a gasket. Mount the nuts on the sensor head: disconnect the cable from the
transmitter, insert the nuts and fasten them on the sensor head. Then reconnect
the cable. A mounting flange is also available (see Fig. 3.2.3). The cable can
also be extended up to 100 metres; see Appendix 3 for details.

M12x1

Ø 12

69

duct wall

sealing

supporting bar

a plugged hole for
reference measurements

flange

Figure 3.2.3 Dimensions of the HMP143A probe (in mm) and

installation in a channel with the help of flange

(part no. HMP233FA) and supporting bar

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Operating Manual U175en-1.5

3.3 Electrical connections

The wiring can be done in either of the two ways shown in Figure 3.3.

mounting on a juction box surface mount

GND

Tout

SHIELD

RHout
Vs

(OHFWULFDOFRQQHFWLRQVP$RXWSXW


9V


*1'

$

$

7

RXW

6+,(/'

5+

RXW

9V

(OHFWULFDOFRQQHFWLRQV9RXWSXW


9V


9

9

Figure 3.3 Electrical connections

Outputs

0...20 mA (4...20 mA) 20...35 VDC 17...24 VAC
min.

L

+ VDC

)(12ohmR

50

0...1 V 9...35 VDC 9...24 VAC

0...5 V 15...35 VDC 12...24 VAC

0...10 V 20...35 VDC 16...24 VAC

Current consumption 6...10 mA + output currents

*1'

7

RXW

6+,(/'

5+

RXW

9V

Electrical connections screw terminals for 0.5 - 1.5 mm2 wires (AWG

15...20), stranded wires recommended

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3.4 Connectors and potentiometers on the main PCB

DISPLAY CONNECTOR

PROBE CONNECTOR

VIO

X15

X16

SHIELD
GRN
YEL
BRN

Toffset

RHoffset

RHoutput

selection

RHgain

Tgain

Spare
jumpers

Toutput
selection

Test connector
for factory use;
leave the jumper
as indicated here

Test connector for
one point calibration

Connectors
for the
current module

Figure 3.4 Connectors and potentiometers on the main PCB

3.5 Selecting the outputs

The HMP140A series transmitters can be ordered with the desired output
signals already selected. If the outputs are changed, the jumpers have to be
moved to corresponding places (see Figure 3.5). For current outputs, see
Appendix 1. Jumper changes may change the output < ±0.15 %FS within the
chosen range; this usually does not give cause to recalibration.

DISPLAY CONNECTOR

Test connector for
one point calibration

PROBE CONNECTOR

VIO
SHIELD
GRN
YEL
BRN

RHoutput

selection

Toutput
selection

Voltage
Toutput selection

0-1V
0-5V
0-10V

Voltage
RHoutput selection

0-1V

0-10V

0-5V

Figure 3.5 Jumper positions for voltage outputs

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Operating Manual U175en-1.5

3.6 Connection to an AC supply

The HMP140A transmitters can also be connected to an AC supply without an
external rectifier. However, when two or more transmitters are connected to
one 24 VAC transformer, a common loop is formed and there is an increased
risk of a short-circuit. To avoid this, always use separate floating supply for
each transmitter (see Figure 3.6 A). However, if several transmitters have to
share one transformer, always connect the phase (∼) to + connector in each
transmitter (see Figure 3.6 B).

A) NO COMMON LOOP FORMED - RECOMMENDED

HMP140 transmitter

HMP140 transmitter

B) COMMON LOOP FORMED -

HMP140 transmitter

supply voltage

Controller

supply volt a g e

supply voltage

signal output

signal output

NOT RECOMMENDED!

Controller

signal output

shared
common line

supply voltage

signal output

HMP140 transmitter

Figure 3.6 Connecting the transmitters to a 24 VAC supply

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4. CALIBRATION

4.1 One-point humidity calibration

The HMP140A series transmitters should be recalibrated approximately once a
year. The interval depends on the operating conditions and the required
accuracy. One-point calibration can be done with Vaisala’s portable HMI41
indicator equipped with an appropriate probe and optional calibration cable
(19116ZZ). The cable is connected to a test connector either on the main
component board of the HMP140A or, if a current output module is installed,
on the module (see Figure 4.1). For more detailed instructions, see the
operating manual of the calibration cable (U218en).

DISPLAY CONNECTOR

PROBE CONNECTOR

VIO
SHIELD
GRN
YEL
BRN

Test connector for
one point calibration
on the main PCB

X15

X16

Test connector for
one point calibration
on the current
module

Current Module

Figure 4.1 Location of the test connectors

4.2 Two-point humidity calibration

The calibration can also be done with the HMK11 or the HMK13B Calibrator,
or the instrument can be sent to Vaisala or a Vaisala represent ative.

4.2.1 Two-point humidity calibration procedure

• Leave the calibrator and the transmitter for at least 30 minutes in the

same space so that their temperatures have time to equalize.

• Place the probe into the calibration hole of the LiCl bottle in the

humidity calibrator.

• Wait for 10 minutes.

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Operating Manual U175en-1.5

• Use the RH offset potentiometer (see Figure 4.2) to adjust the output

signal to the value given in the calibration table (Chapter 4.4).

• Place the probe into the calibration hole of the NaCl bottle in the

calibrator.

• Wait for 10 minutes.

• Check that the reading corresponds within the desired accuracy to the

reading given in the calibration table. If not, adjust the reading with
the RH gain potentiometer (see Figure 4.2).

• Check again the reading at the first point and adjust if necessary.

DISPLAY CONNECTOR

PROBE CONNECTOR

Figure 4.2 Calibration potentiometers

4.3 Temperature calibration

One point temperature calibration can be performed with the HMI41 equipped
with an appropriate probe and optional calibration cable if the accuracy of
+0.5 °C is sufficient. For further details, see the operating manual of the
HMI41 and calibration option.

Toffset

RHoffset

RHgain

Tgain

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U175en-1.5 Operating Manual

4.4 Calibration table

Temperature °C 15 20 25 30 35

°F 59 68 77 86 95

LiCl %RH *) 11.3 11.3 11.3 11.3

4...20 mA mA 5.81 5.81 5.81 5.81

0...20 mA mA 2.26 2.26 2.26 2.26

0...1 V V 0.113 0.113 0.113 0.113

0...5 V V 0.565 0.565 0.565 0.565

0...10 V V 1.13 1.13 1.13 1.13

NaCl %RH 75.6 75.5 75.3 75.1 74.9

4...20 mA mA 16.10 16.08 16.05 16.02 15.98

0...20 mA mA 15.12 15.10 15.06 15.02 14.98

0...1 V V 0.756 0.755 0.753 0.751 0.749

0...5 V V 3.780 3.775 3.765 3.755 3.745

0...10 V V 7.56 7.55 7.53 7.51 7.49

*) LiCl solution must not be used or stored in temperatures below +18 °C (+64 °F) ;

otherwise the equilibrium humidity of the salt solution changes permanently

Table 1 Greenspan’s calibration table with output values accordin g to

the chosen scale

5. MAINTENANCE

5.1 Replacing the HUMICAP180 sensor and the filter

Remove the damaged sensor and insert a new one. Handle the sensor by the
plastic socket. DO NOT TOUCH THE SENSOR PLATE. Check the output
after sensor change. If it deviates too much from the reference value,
recalibrate the transmitter. Note that even after sensor change, the accuracy is
still +7 %RH.

Replace a dirty filter to ensure a maximum lifetime for the sensor. Do not try
to clean the filter. The sensor can be cleaned with distilled water; if this does
not help, replace the sensor. Do not use any mechanical methods.

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Operating Manual U175en-1.5

6. TECHNICAL DATA

6.1 Relative humidity

Measurement range 0...100 %RH

Accuracy (including non-linearity and repeatibility)
when calibrated against salt solutions (ASTM E104-85):

0...90 %RH +2 %RH

90...100 %RH +3 %RH

Temperature dependence:

dRH (%RH)

2

1.5
1

0.5

0

-0.5

-1

-1.5

-2

-20

-10

0102030

40

50

6

T (°C)

Response time (90%) 15 s at +20 °C in still air (with sintered filter)

Maximum error between
the display and the outputs 0.2 %RH

Humidity sensor HUMICAP180

6.2 Temperature

Measurement range -20...+60 °C

Typical accuracy at:
+20 °C +0.2 °C

-10...+40 °C +0.3 °C

-20...+60 °C +0.4 °C

Temperature sensor Pt 1000 IEC 751 Class B

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6.3 General

Power supply
current outputs: 20...35 VDC 17...24 VAC
min. 12 +

RL(ohm)

50

0...1 V 9...35 VDC 9...24 VAC

0...5 V 15...35 VDC 12...24 VAC

0...10 V 20...35 VDC 16...24 VAC

Current consumption 6...10 mA + output currents

Electrical connections screw terminals for 0.5 - 1.5 mm2 wires (AWG

15...20), stranded wires recommended

Alternative analogue
output signals (scalable) 0...20 mA (4...20 mA)

0...1 V, 0...5 V, 0...10 V

NOTE! Output scales correspond to 0…100 %RH and -40…+60°C.

External loads for
current outputs < 500 Ω

0...1 V > 1 kΩ (to ground)

0...5 V > 5 kΩ (to ground)

0...10 V >10 kΩ (to ground)

Operating temperature range
for electronics -20...+60 °C
with display option 0...+50 °C

Storage temperature range -40...+80 °C

Operating humidity range 0...100 %RH

Bushing for ∅ 7...10 mm cables

Sensor protection
standard membrane filter, part no. 17039HM
option plastic grid, part no. 17038

Cable length of HMP143A
standard 2.5 m
maximum 100 m (user extendable, see Appendix 3)

Housing material ABS plastic

Housing classification IP65 (NEMA 4)

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Operating Manual U175en-1.5

6.4 Electromagnetic compatibility

6.4.1 Emissions

Test: Setup according to:

Radiated interference EN55022 (class B)

6.4.2 Interference

Test: Setup according to: Performance:

Electrostatic discharge IEC 801-2 criteria B

RF-radiated fields IEC 801-3 criteria A
(allowed temporary effect
±1 °C in temperature)

Electrical fast transients IEC 801-4 criteria B

7. SPARE PARTS AND ACCESSORIES

Order code Description

HMP233FA mounting flange for the HMP143A
19326 junction box for the HMP143A cable ex tension

(seeApp.3)
1535 extension cable for the HMP143A (see Appendix 3)
17039HM membrane filter
17038 plastic grid
HUMICAP®180 humidity sensor

GUARANTEE

Vaisala issues a guarantee for the material and workmanship of this product
under normal operating conditions for one (1) year from the date of delivery.

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U175en-1.5 Operating Manual

Exceptional operating conditions, damage due to careless handling and mis­application will void the guarantee.

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U175en-1.5 Appendix 1

APPENDIX 1: CURRENT OUTPUT MODULE

Spare jumpersCurrent module

X15

T output
selection

X16

RH output
selection

Figure 1

The current module is available only for HMP142A and HMP143A
transmitters. To install the current module to connectors X15 and X16, first
disconnect the jumpers (4 pcs). Insert them to the connector for spare jumpers
(see Figure 1) and install the current module. Note that the module must be
installed exactly as indicated in Figure 1. The jumpers for RH and T output
selections must be connected in two middle pins of the connectors (Figure 1).
Recalibrate the transmitter after having installed the current module. The
maximum error in output without recalibration is ± 0.5 %FS.

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U175en-1.5 Appendix 2

APPENDIX 2: SETTINGS OF THE LOCAL DISPLAY

°F

RH/T

°C

Figure 1 Location of the RH/T button and the °C/°F jumpers

The reading on the local display (relative humidity or temperature) can be
chosen by pressing the RH/T button beside the display. At power-up, the
display always shows the relative humidity reading. This can be changed to
temperature reading by pressing the RH/T button once. Further pressings will
change the reading between RH and T.

The temperature unit (°Celsius or °Fahrenheit) is chosen with the jumper on
back of the local display unit. For °C, the jumper is connected to the lower
position and for °F, it is connected to the upper position (see Figure 1).

NOTE!

The HMP140A series transmitters with the local

display and current output cannot be re-scaled.

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Appendix 2 HMI41-Uxxxen-1.1

2 1999-12-08

HMP140A SERIES

S

U175en-1.5 Appendix 3

APPENDIX 3: HMP143A PROBE CABLE EXTENSION

The cable of the HMP143A probe can be extended up to 100 metres with the
help of the extension set including a junction box (part no. 19326) and a
shielded six wire extension cable (part no. 1535).

The junction box has a 5-pole terminal block and two PG9 lead-throughs. The
extension cable is a shielded 6 x 0.22 mm2 copper wire cable. This cable
enables the extension without the need for transmitter adjustments. The user
can also use some other cable for this purpose provided that it is a shielded
copper wire cable. A shielded cable is recommended as it ensures the best
possible EMC protection. The diameter of the cable should not exceed 7 mm
as larger cables do not fit to the lead-through of the transmitter.

The HMP143A probe head uses a combined signal ground and supply voltage
ground. Ground wire resistance Rc causes an offset type error to the
transmitter output. The error is -0.11 x Rc both in %RH and in °C. This means

that if maximum error allowed is e.g. -0.3 %RH or -0.3 °C, the ground wire
resistance should not exceed 2.7Ω. The resistance of the cable 1535 is
minimized by connecting three wires as a ground conductor (see Figure 1).
Possible error can also be leveled out by readjusting the transmitter offset
(RH offset and T offset).

PROBE CONNECTOR ON THE
HMP143 PCB; THE COLOURS
SHOW THE DIRECT CONNECTION
OF THE HMP143 PROBE HEAD

PROBE CONNECTOR

VIO
SHIELD
GRN
YEL
BRN

Figure 1 Schematic of the extension set connections

HMP143 PROBE
CONNECTOR

THREE WIRES CONNECTED
TOGETHER (WHT, GRN, RED)

EXTENSION
CABLE

CABLE SHIELD

BLU

GREY
YEL

BLK

JUNCTION
BOX

HMP143 CABLE

VIO
SHIELD
GRN (ground)
YEL
BRN

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HMP140A
Appendix 3 U175en-1.5

TECHNICAL DATA

Junction box (part no. 19326)

Housing:

material ABS plastic
dimensions 65 x 50 x 35 mm (l x w x h)
classification IP 65
temperature range -40...+80 °C

Lead-throughs:

size PG 9
cable diameter 4...7 mm
housing classification IP 68

Terminal block:

max. wire area 1.5 mm

Extension cable (part no. 1535)

Type PFSK 6 x 0.22 mm
Wire resistance 80 Ω / km
Covering braided, tinned copper wire
Cross-sectional area
of the wires 0.22 mm
Cover PVC, light grey
Temperature range -30...+70 °C
Wire colours red, blue, green, yellow, white, black

2

2

2

(DEF-STAN 61-12)

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