Specifications

M GD-100 M anual
6109-9000 Rev 3 41
Step Sensor Board Exchange
1 Power off the unit and rem ove lid of sensor enclosure.
2
Note the color code of the cable in positions 1,2,3 and 4 of
the connector block.
3
Undo the cable and 2 screws securing the sensor board and
remove the board.
4
Fit the new pre-calibrated sensor and reconnect the cable in
the correct color sequence at positions 1,2,3 and 4.
5
Power on the unit and allow to stabilize for 15 minutes
(minimum).
6
Check voltage readings on positions 1,2,3 and 4 (see Table 1
on page 45) to ensure that wiring is correct. Note also in the
table how to monitor the sensor as it stabilizes.
7 Carry out a bump test to confirm the sensor is responding.
8
Keep records of the test date, sensor serial number, and any
observations.
6.8. On-Site Gas Calibration (One-Alarm Unit)
This section and the next cover calibration using calibration gas
cylinders. Bacharach offers a c alibration kit that consists of a cali bration
gas cylinder and a flow regulation valve with flexible non-absorbent
tubing and vented calibration hood.
In some cases this option may be expensive relative to sensor exchange
because of the cost of visiting a site, calibration gas, etc.
The procedure involves electrical s et-up followed by adjustment using
calibration gases. Equipment required is as follows:
• Gas cylinder wit h the appropriate target gas and concentration
• Fixed flow regulator – rate 0.3L/min
• A voltmeter.
NOT E: This calibration procedure is for a one-alarm unit
.
For t wo-alarm units, refer to the calibration procedure in the
next section.