Vaisala PTU200 - Manual (Page 8)

U SER ' S G UIDE _______________________________________________________________________
4 ____________________________________________________________________ M210195 EN -A
Humidity and temperature measurement
The HMP45A-P and HMP45D probes are designed for the
measurement of relative humidity and temperature. The humidity
measurement is based on a capacitive thin film polymer sensor,
HUMICAP

180. The temperature measurement is based on resistive
platinum sensors. Both the humidity and the temperature sensors are
located at the tip of the probe and protected by a membrane filter.
The HMP45A-P probe has the HUMICAP

180 polymer sensor and
the Pt 1000 resistive platinum sensor for RH and T measurements,
respectively. The 20 metres cable of the HMP45A-P is connected to a
board with a plug and thus the user can cut the cable to suitable length
and reconnect it easily. The HMP45A-P and the HMP45D have a
similar humidity output, but the temperature output is active in the
HMP45A-P (voltage output 0-1V) and passive in the HMP45D
(resistive output Pt 100). The HMP45D comes with a 3.5-meter
connection cable. The cable is soldered directly to the board inside the
transmitter.
When the humidity measurement is not required, the PTU200 can be
supplied with a small, high stability wire-type Pt100 temperature
sensor head.