Humidity Sensors FK120J (capacitive) Humidity-Temperature Sensors TFK120J (capacitive)0 pages

Galltec
Galltec Mess- und Regeltechnik GmbH MELA Sensortechnik GmbH
D-71145 Bondorf . Germany
Tel. +49 (0)7457-9453-0 . Fax +49 (0)7457-3758
E-Mail: sensoren@galltec.de . Internet:www.galltec-mela.de

D-07987 Mohlsdorf (Thüringen) . Germany
Tel. +49(0)3661-62704-0 . Fax +49(0)3661-62704-20
E-mail:mela@melasensor.de . Internet: www.galltec-mela.de

Humidity Sensor typeFK120J (capacitive)
with current or voltage output, to determine air humidity in
room version.

Humidity-temperature Sensor type
TFK120J (capacitive)
with current or voltage output, to determine air humidity and
temperature in room version.

FK120J for humidity
TFK120J for humidity and temperature
Technical Data
measuring range humidity .................................. 0...100%rh
working range ......................................................... 10...95%rh
measuring accuracy .................................................. ±3.5 %rh
measuring medium.......... air, pressureless, non-corrosive/condence
temperature coefficient ............. 0.05%/K at 20°C and 50%rh
adjustment ...................... at average air pressure 430m NN
half-life period (v=2m/sec) ............................... approx. 10 sec
output humidity
....... 0...20mA or 0...10V 4-wire system
................... or 4...20mA 2- wire system
measuring range temperature
.................. 0...+50°C, -10...90°C1), -30...60°C, 0...100°C1)
measuring accuracy ....................................................... ±0.8 K
working range ........................................................ -10...+60°C
output temperature ....... 0...20mA or 0...10V 4 wire-system
.................. or 4...20mA 2 wire-system
linearity tolerance ........................................................... <0.5%
operating voltage ..................................... 15..24V DC / 24V AC
max. load for current output ..................................... 500 ohms
min. ballast resistance for voltage-output .............10 k ohms
internal consumption per measuring range (4-wire) ....15 mA
permissible ambient temperature ........................ -10...60°C
permissible air speed ..............................................15 m/sec.
fixing ......................... slots in housing base for wall mounting
mounting position ...... preferably ventilation slots at rightangles to wind direction
contact ......................... connecting terminals in the housing
connecting terminals ...........................................................
............. for conductor cross-sections 1.5mm2
cable connection .......................................... simple shielding
EMC tested .............................. to EN 50 081-2, EN 50 082-2
housing ............................. impact resistant plastic, light grey
dimensions .................................................... 115x70x43mm
protective system ............................................................... IP20
weight ........................................................................... ca 0.2 kg

1) please heed working range

Description of the sensor
The FK120J (humidity only) / TFK120J (humidity and
temperature) sensor measures the air humidity by means
of a humidity-dependant condenser. The capacitive
humidity measuring element, produced using thin-film
technology, consists of a base plate, on which the
electrodes are housed, and a hygroscopic polymer layer
above it. The hygroscopic polymer layer absorbs water
molecules from the medium to be measured (air) or
releases them, thereby altering the capacity of the
condenser. In a tandem-arranged electronic device, the
change in capacity is processed via integrated signal
preprocessing into standardised signals 0...20mA or
0...10VDC or 4...20mA.
The measuring element is protected in the housing. The
sensors are designed for pressureless systems - the
measuring medium is non-corrosive air.
The TFK120J sensors also contain a Pt100 resistance for
simultaneous temperature measurement. Its measured
values are likewise converted into stan-dardised signals
0...20mA or 0...10VDC or 4...20mA.

Maintenance
The measuring element is maintenance free when the
surrounding air is clean. Agents that are corrosive and
contain solvents, depending upon the type and concentration of the agent, can result in faulty measurements and
cause the measuring element to break down. Substances
deposited on the sensor are damaging as they form a
water-repellent film. Such substances are resin aerosols,
lacquer aerosols, smoke deposits etc.
Please consult the application notes for humidity sensing
elements (product info sheet no. A 1) or check with the
manufacturer for further information which you need to bear
in mind when using humidity sensors with capacitive sensing elements.

ATTENTION: The guarantee is no longer valid of the interior
of the measuring element has been accessed.

This information is based on current knowledge and is intended to provide details of our products and their possible applications. It does not, therefore, act as a guarantee of specific properties of
the products described or of their suitability for a particular application. It is our experience that the equipment may be used across a broad spectrum of applications under the most varied conditions
and loads. We cannot appraise every individual case. Purchasers and/or users are responsible for checking the equipment for suitability for any particular application. Any existing industrial rights
of protection must be observed. The perfect quality of our products is guaranteed under our General Conditions of Sale. Issue : January 2011 FK120_E. Subject to modifications.