Detector Calibration - S&S Northern MERLIN CO DETECTOR X Installation Operation & Maintenance

Installation, Operation & Maintenance Manual

Detector Calibration

Do not conduct calibration of sensors in conditions outside any recommended ranges.
Use the specified calibration gas only and a fixed flow regulator.
Always use equipment in accordance with their safety datasheets.
Calibration gases must be prepared and mixed to traceable international standards.
Ensure you have the correct gas for the device type prior to application.
Screw the regulator/valve into the gas cylinder outlet.
Once sealed, the regulator pressure gauge (if available) will indicate cylinder pressure.
Always remove the regulator/valve after use.
All cylinders will re-seal upon removal of the regulator/valve.
If a gas sensor is exposed to a concentration significantly above the measuring range it should be
recalibrated as soon as possible afterwards.
To recalibrate a detector, the following procedures and gases MUST be used.
Why recalibrate a detector?
Detectors are pre-calibrated at the time of manufacture, therefore a re-calibration is only required
periodically (annually) to compensate for its sensitivity and accuracy that can be inhibited by external
factors. Dust, humidity, temperature fluctuations, cleaning products, contaminants or sensor drift (ageing)
can cause a decline in sensitivity, accuracy and eventual failure.
Regular gas sensor recalibration is important to prolong the operational life and make sure the detector is
able to detect a concentration of gas as accurately and early as possible. Typical accuracy of gas
measurement is within 10% of the detected concentration.
How often shall I recalibrate a detector?
Calibration should coincide with the annual service message that appears on the detector after each year
of service/operation. Depending on the application and environmental factors, a recalibration can be
conducted at a higher frequency determined by the end user but must be executed by trained personnel.
What equipment do I need to perform recalibration?
Contact your S&S Northern representative for details of suitable calibration kits and gases.
Kits usually consist of a certified gas cylinder; flow control regulator, tube pipe and applicator cone.
To recalibrate a detector, the following gases and concentrations MUST be used.
Detector Type
CO - Carbon Monoxide
NG - Methane
LPG - Liquid Petroleum Gas
H - Hydrogen
O - Oxygen
2
All certified test gases supplied by S&S Northern are classified as non-flammable and non-toxic,
however, they do contain gas under pressure and may explode if heated to extreme temperatures
and cause asphyxiation in high concentrations.
DETX-IOM Iss: 7 02-21
Calibration Gas
120ppm balance in air.
0.5% BV (balance in air) 10% LEL
0.2% BV (balance in air) 10% LEL
4000ppm (balance in air) 10% LEL
If no residual gas is present then the background air can be used to
perform calibration.
Merlin Gas Detector-X
Recommended
gas flow rate
Typically 0.3 L/Min
@ 70bar
15