62 • Calibration Mode
Gas Tracer Operator’s Manual, CSA Version
Calibration Mode
Calibration mode allows you to calibrate the Gas Tracer’s sensor response, bump
test the unit, and calibrate the PPM sensor.
CAUTION:
BEFORE EACH DAY’S USAGE, SENSITIVITY IN THE % LEL
RANGE MUST BE TESTED ON A KNOWN CONCENTRATION OF
THE COMBUSTIBLE TARGET GAS, METHANE, EQUIVALENT TO
25 - 50% OF FULL SCALE CONCENTRATION (The % LEL full scale is
100% LEL). ACCURACY MUST BE WITHIN -0 to + 20% OF
ACTUAL. ACCURACY MAY BE CORRECTED BY FOLLOWING
THE CALIBRATION INSTRUCTIONS FOR THE COMBUSTIBLE
CHANNEL BELOW.
If the combustible channel passes the above response test and does not require
calibration, the unit should still be calibrated periodically. The optimum
frequency of calibration depends heavily on how the Gas Tracer is used. For
example, instruments used daily may need to be calibrated weekly or monthly,
while instruments that are used only a few times a year may need to be calibrated
before each use. Typical calibration frequencies range from monthly to quarterly.
Make sure to perform the combustible channel response test as described above
and make sure to develop a calibration schedule tailored to your application that
takes this test and required calibration resulting from this test into account.
You can program the Gas Tracer to notify you when it is due for calibration. See
“Updating the Calibration Reminder Setting” on page 148.
Calibration/Bump Test Supplies and Equipment
To calibrate or bump test the Gas Tracer, you will need:
• Known calibrating samples of the gases being detected. The combustible and
toxic gas samples should have concentrations in approximately the middle of
the range of detection. An oxygen-free source, such as 100% nitrogen is
recommended for setting the oxygen zero when using single calibration.
• A demand-flow regulator to provide adequate sample gas flow
• Non-absorbent tubing
• Humidifier tube (for calibration of ppm sensor)
CAUTION:
If you are using a calibration kit that includes a gas bag and a fixed flow
regulator or dispensing valve, do not apply gas directly to the Gas Tracer
with the regulator or valve or damage to the pump will result. See
“Appendix A: Calibrating or Bump Testing with a Sample Bag” on
page 176 for instructions to properly use a gas bag kit.
To calibrate the %LEL, Oxygen, and CO sensors at the same time, automatically,
with no need for a zero-oxygen source, you can use the auto calibration feature
with a 3-gas cylinder. This section includes instructions for auto calibration and
bump testing with a demand-flow regulator, a 3-gas cylinder, and a %volume
methane cylinder. This section also includes instructions for calibrating one
channel at a time using single calibration.
