Table of Contents
Advertisement
Sensor Calibration
Gas detectors must be calibrated and periodically checked to ensure detectors accuracy and system
integrity. It is important to install stationary gas detectors at locations where the calibration can be
performed easily. The intervals between calibration can be different from sensor to sensor. However, it is
good practice to check the detector during the first 30 days after installation. During this period, it is
possible to observe how well the detector is adapting to its new environment. If the detector functions
properly for 30 continuous days, this provides a good degree of confidence about the installation. Any
possible problems can be identified and corrected during this time. Experience indicates that a detector
surviving 30 days after the initial installation will have a good chance of performing its functions for the
duration expected. Most problems such as inappropriate detector location, interference from other
gases, or the loss of sensitivity will arise during this time. Afterward, a maintenance schedule, including
calibration intervals, should be established.
Normally, a 6-monthly calibration period is adequate to ensure the effectiveness and sensibility of each
sensor. This check will also afford you the opportunity to maintain the system's accuracy.
Calibration Procedure
Calibration of the gas detector includes two steps. First the "zero" must be set and then the "span" must
be calibrated.
1. To initiate calibration press and hold the tactile button on the PCB or place the magnetic gas
calibration cup.
2. After 5sec all LED's will flash.
3. After 2 more seconds the yellow LED will turn OFF, red LED is ON and the green LED is flashing
once every second for the period of 30 seconds. In this case you may chose from the following:
-To calibrate the sensor – continue holding the button and apply zero gas;
-To refuse calibration on ZERO air – release the button (remove the magnetic cap) – red LED will
flash for 2 seconds.
4. Green LED and red LED start to flash alternately. Now you must apply the span gas and again
press and hold the button or place the magnetic gas calibration cup. Now the alarm levels are
automatically adjusted. Red LED lights and green LED are flashing twice at every 2 seconds for 30
seconds. In this case you may choose from the following:
-To calibrate the sensor – continue applying span gas for 30 seconds and the red LED will flash for
2 seconds confirming alarm levels settings;
-To refuse calibration of alarm levels – release the button or remove the magnetic cap and the
red LED will flash for 2 seconds.
5. When you complete the above steps, calibration is finished, and all LED's will flash for 5 seconds.
NOTE: If during the calibration you release the button or remove the magnetic cap for more than 4
minutes, calibration will be terminated and the previously saved values for pure air and alarm levels will
be recovered.
9
Advertisement
Table of Contents
