Vaisala HMM30C Operating Manual

HMM30C MO DULE HMM30C

U312en-1.3 Operating Manual

99-11-29

HMM30C humidity module

GENERAL

The HMM30C humidity module is an open print, which is connected with two screws. Its
small sensor head is separated from the circuit board with a cable. Mounting dimensions
are shown in Figure 1.

215 (8.46)

ø12

1500 (59.05)

49 (1.93)

24 (0.94)

55 (2.16)

(0.47)

42.5 (1.67)

Figure 1 Mounting dimensions in mm (in inches)

ELECTRICAL CONNECTIONS

Make connections according to Figure 2.

+

OUT

-

213

DC/AC
POWER
SUPPLY

V/mA

Figure 2 Electrical connections

HMM30C HMM30C MO DULE
Operating Manual U312en-1.3

2 99-11-29

NOTE

If the metal tube of the HMM30C is in contact with
metal parts (e.g. chamber wall) that are in galvanic
contact with the power supply ground, problems may
occur in strongly condensing situations. If the
condensed water forms a conductive path between the
tube and the sensor legs, the generated currents in this
path may cause electrochemical reactions and corrosion
in the probe structure. Therefore, it is recommended to
install the probe so that the metal tube is galvanically
isolated from the chamber wall.

OPERATING THE MODULE

The desired output range is chosen with appropriate jumpers (see Figure 3). When the
output has been chosen and the module has been connected to an external power supply,
it is ready for use.

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Figure 3 Output selections and calib ration conn ectors and

potentiometers

ONE POINT HUMIDITY CALIBRATION

The calibration can be checked with Vaisala’s one point calibrator: the HMI41 indicator
equipped with a suitable reference probe (e.g. HMP46) and the calibration cable
19165ZZ. Make the necessary adjustments with the dry-end calibration potentiometer. If a
more accurate two point calibration is preferred, the HMK15 or the HMK13B calibrators
with salt solutions are recommended. For detailed instructions, see the corresponding
manuals.

HMM30C MO DULE HMM30C

U312en-1.3 Operating Manual

99-11-29

The calibration interval depends on the surrounding conditions and the desired accuracy.
It is recommended to perform a calibration at least once a year. However, long term
exposure to certain chemicals and gases, e.g. some organic solvents, acids or bases may
cause drift in the sensor response. If there is a reason to believe that such conditions exist,
it is recommended to check the calibration at a shorter interval after taking the HMM30C
into use. Make the first check/adjustment after 6 months and 12 months and later extend
the interval to one year.

REPLACEMENT OF THE HUMICAP SENSOR OR THE FILTER

If the sensor is damaged for some reason, remove it 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
module.

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

TECHNICAL DATA

Relative humidity

Measurement range 0...100 %RH

Accuracy at +20 °C
(including calibration
inaccuracy, linearity and
repeatability): ±2 %RH (0...90 %RH)

±3 %RH (90...100 %RH)

Temperature coefficient ±0.04 %RH/°C (NOTE: after T compensation)
Humidity sensor Vaisala HUMICAP capacitive polymer sensor

Electronics

Output Supply voltage
DC DC AC

0...1 V 10...35 V 9...24 V

0...5 V 14...35 V 12...24 V

0...10 V 19...35 V 16...24 V

0...20 mA 10...35 V 9...24 V (RL = 0 ohm)

0...20 mA 20...35 V 17...24 V(RL = 500 ohm)

Recommended external
load for outputs > 10 kohm

Current consumption 15 mA max.

HMM30C HMM30C MO DULE
Operating Manual U312en-1.3

4 99-11-29

Electrical connections Screw terminals for wires 0.5...1.5 mm²

(AWG 20...16)

Operating temperature

electronics -5...+55 oC (+23...+131 oF)
sensor head -40...+180 oC (-40...+350 oF)

Survival temperature range

sensor head -70...+180 oC (-94...+350 oF)

Long-term humidity range
(electronics) 0...85 %RH

Mechanics

Sensor protection Sintered filter Ø 12 mm
PCB dimensions 55 x 42.5 x 23 mm
Weight 144 g
Cable length 1.5 m (5 ft.)

SPARE PARTS AND ACCESSORIES

Order code Description

0195

sintered filter ∅ 12 mm

HUMICAP K HUMICAP® 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.
Exceptional operating conditions, damage due to
careless handling or misapplication will void the
guarantee.