PTR 225 / PTR 225 S PTR 237 - Schoonover, Inc.

2.2.5 Identification
For the purpose of identifying the connected type of
transmitter and the pressure range, the PENNING transmitter
is equipped with an identification resistor
(R = 100 kΩ) between Pin 4 and Pin 2. This resistor may
be sensed by connected operating or control units so
that these can automatically adapt.
Key to Fig. 4
1 Monitor output
2 Potentiometer for
adjustment of the
switching threshold
3 LED (green)
4 Connector
Pin 1 Ground
Pin 2 Normally open relay contact
Pin 3 Center relay contact
Pin 4 Normally closed contact
2.2.6 Switching Threshold (PTR 225 S)
The built-in switching threshold may be adjusted through
potentiometer (4/2) in the range between 1·10 -3 -1·10 -9
mbar.
To adjust the threshold remove the cap (4/2) and use a
screwdriver to adjust the threshold to the desired level.
In order to check the adjustment, a voltmeter may be
connected to the monitor output (4/1) (see Section 2.2.7
and Table 1 in the Annex).
The threshold switch is a floating relay (changeover
contact) which may be accessed via pluggable screw
terminals (4/4). When the pressure drops below the adjusted
threshold, a green LED (4/3) comes on.
In the case of a fault (i.e. discharge not present) or if the
supply voltage has been switched off the relay contacts
return to their rest position.
Fig. 4 PENNING transmitter PTR 225 S
1
4
1
2
3
4
14 GA 09.308/4.02 - 05/97
14