10
300710168_002_C1 - 01/2018 - © Leybold
Recommended electrical connections
Do not connect the electrical supply ground (pin 2) to the signal ground (pin 5). If you do, the TTR 91 R output signal
will be inaccurate.
When using the TTR 91 R in an electrically noisy environment you should ensure that your measuring equipment is
adequately immune to interference. All Leybold controllers have adequate immunity.
The set-point output on pin 6 is an active low open-collector transistor suitable for driving a d.c. relay or control logic.
If you connect a relay you must use a suppression diode, to protect the gauge from transient voltages generated
when the relay is switched off.
Make a connection to pin 7 if you require remote calibration. Momentarily (>50ms) connect pin 7 to pin 2 (ground) to
automatically adjust the atmosphere or vacuum reading. Refer to the Maintenance section for the correct procedure
1
TTR 91 R electrical connector
socket
2
Cable electrical connector plug
3
Electrical supply
4
Voltmeter
5
d.c. relay (optional)
6
Back EMF suppression diode
(optional)
7
Remote
calibration
switch
(optional)
