Instruction manual

Instruction Manual
Model 4101-28/5100-28 IR Gas Sensor Module (7/03) Page:
6
3.0 Calibration
3.1 Overview
All applications require an initial calibration upon
power up and before putting the modules into service.
This initial calibration is considered a local calibra-
tion, begun and completed at the module. In the Sen-
try applications, the initial local calibration is to be
followed up with a global calibration at the control-
ler. (See Chapter 5 in the Sentry manual, T121001).
In the 4-20mA applications a system calibration un-
dertake at the control device may be necessary.
During the local calibration, the module output is
clamped to prevent the control devices from interpret-
ing the calibration gas as an alarm even.
System response should be checked every 6-9 months
and the modules should be recalibrated as necessary
or at least every year.
3.2 Local Calibration Procedure
You will need the following items to
complete calibration:
• 1260-01: Cylinder of Air if none concentration of
gas in background is greater than zero
• 1260-02: Cylinder of 50% LEL Methane balance
air or 1256-28: Cylinder of 50% LEL Propane bal-
ance air.
• 1256-04: 2LPM flow Regulator.
• 1255-02: Gas Calibration Tubing, PTFE or equal
1/4 OD
• 1250-04: Calibration Kit is a case for storage of 2
cylinders and contains the tubing and regulator
3.3 Start Calibration
1.Deliver air if necessary for 2 minutes at 2LPM.
Remove at step noted below.
2.Place and hold curved side of the magnet attached
to the module at the 10:00 position on the module
to commence calibration. The display will indicate
the "Switch is on" followed by "Setting Zero". The
status LEDs goes from slow pulsing green to steady
green.
3. Remove magnet.
4. Remove air.
5. The status LED will go green indicating span gas
may be applied.
6. Follow the prompts on the display;
7. Deliver calibration gas for 3 minutes at 2LPM.
8. Remove the gas after 3 minutes or when
prompted.
9. The status LED will go to green indication calibra-
tion was successful.
10. When the concentration of calibration gas falls to ap-
proximately 12% LEL the module will come out of the
calibration mode and be in normal operation.
11. The status LED will return to its normal pulse rate.
12. Perform a system calibration.
13. Follow chapter 5 in the Sentry manual or follow the own-
ers manual of the control device.