Installation & Operation Manual Merlin GDP2X
GDP2X - IOM Iss: 7 03-21
14
Field Calibration
1.
Carefully remove the detector cover to access the circuit board.
2.
Ensure that service mode has been enabled on the control panel.
3.
Short out the unmarked service headers for ~3s.
4.
A calibration prompt will appear for a limited time on the detector screen.
5.
Offer up the applicator hose/cone and cover the gas sensor fully.
6.
Open the valve/regulator and deliver the gas at a pre-set flow rate.
7.
Wait for a ‘successful’ message to appear on the detector screen.
8.
Remove applicator hose/cone and turn the gas cylinder regulator/valve off.
9.
After ~5s the detector will return to normal operation.
(Note: the annual service reminder is automatically reset)
10.
Carefully replace the back cover.
See below for calibrated gas concentrations that must be used to calibrate your detector.
Detector Type
Calibration Gas
CO - Carbon Monoxide
120ppm (balance in air).
NG - Methane
0.5% BV (balance in air)
LPG - Liquid Petroleum Gas
0.2% BV (balance in air)
H - Hydrogen
4000ppm (balance in air)
O
2
- Oxygen
20.9% (balance in Nitrogen).
Gas sensor location, types and response times
The time for sensors to respond to their target gas will vary
on the type of gas sensing element. You should always refer
to the specification for information on sensor type and alarm
levels i.e. electro-mechanical sensors (such as CO and O
2
)
will react to its target gas slower than semi-conducting
sensor types (such as methane and LPG).
Failed Field Calibration
If field calibration is unsuccessful a screen text ‘Fail’ will appear.
After ~5s the detector will return to a normal state as it was pre-service but the service reminder
message will remain flashing. Check that the correct gas and concentration has been applied and
gas was applied before contacting your supplier.
