Sensor Installation - Hach ORBISPHERE 51 Série Manuel D'utilisation Simplifié

Analog inputs (when ext. press. sensor is directly
connected):
14. GND
15. Green: Input ext. press. sensor P+
16. White: Input ext. press. sensor P-
17. Red: Output ext. press. sensor +
18. Black: Ground (GND)
Note: On multi channel systems, the external pressure sensor must be wired to the channel 1 measurement board, but the signal is
used to compensate all channels.
4.6.5 Measurement alarm relays
The three output relays are located on the measurement board.
They can be individually configured to Normally Open (NO) or to Normally Closed (NC) by
physically moving the jumper on each relay. The LDO measurement board is used as an
example:
• Upper relay (J14) is set to NC
• Middle relay (J18) is set to NO
• Lower relay (J19) is shown with no jumper
The following table shows the relay number associated with the numbered connection for each
sensor type:
Sensor type
LDO
TC

4.7 Sensor installation

4.7.1 Purge gas system for the TC sensor
Do not place the TC sensor into a liquid sample until a constant supply of dry purge gas has been connected, as
liquid could condense inside the measuring chamber and cause damage to the thermal conductor chip.
To ensure the continuation of purge gas while the sensor is in contact with the sample, it is highly
recommended to use a backup purge gas cylinder with an automatic changeover valve that activates
when the first cylinder is empty.
The use of an ORBISPHERE Model 29089 gas regulator (or similar) is also recommended to deliver
a constant, pressure regulated supply of dry purge gas to the sensor, filtered to 40 μm.
In addition, and to prevent any damage to the sensor electronics, the use of a purge safety backup
unit (ORBISPHERE Model 32605) is highly recommended to ensure the supply of purge gas remains
uninterrupted to the sensor in the event of a mains power outage.
14 English
Analog inputs (when ext. press. sensor extension,
Part N° 32548.xx, is used):
12. GND
13. Green: Input ext. press. sensor P+
14. Yellow: Input ext. press. sensor P-
15. White: Output ext. press. sensor +
16. Brown: Ground (GND)
Relay 1
J14
J4
N O T I C E
Relay 2
J18
J5
Relay 3
J19
J6