65-2661RK-03-04 M2A Transmitter Operator’s Manual
32
Calibration Frequency
Although there is no particular calibration frequency that is correct for all applications, a
calibration frequency of every 6 months is adequate for most infrared carbon dioxide
transmitter applications. Unless experience in a particular application dictates otherwise,
RKI Instruments, Inc. recommends a calibration frequency of every 6 months.
If an application is not very demanding, for example detection in a clean, temperature
controlled environment where calibration adjustments are minimal at calibration, then a
calibration frequency of every 9 to 12 months is adequate.
If an application is very demanding, for example if the environment is not well controlled,
then more frequent calibration than every 6 months may be necessary.
Determining Response Time
Since the detector junction box is installed remotely from the M2A, the response time of
the detector will depend on the length of flexible tubing that is attached to the calibration
adapter/splash guard. To determine the response time based on the length of tubing
connected:
1.
Place the M2A into its calibration mode or disable external alarms.
2.
Note the current gas reading displayed at the M2A.
3.
Screw the regulator into the calibration cylinder. Do not use a zero air cylinder for this
operation.
4.
Use the flexible tubing coming from the calibration adapter/splash guard to connect
the regulator to the calibration adapter/splash guard.
5.
Turn the regulator’s on/off knob counterclockwise to open the regulator. Gas will
begin to flow. Take note of the time or start a stopwatch.
6.
When you first start to notice an increase in the gas reading, note how much time
passed between starting the gas flow and noticing a reading response.
7.
Turn the regulator’s on/off knob clockwise to close the regulator.
8.
Unscrew the regulator from the calibration cylinder.
9.
Disconnect the calibration adapter/splash guard’s flexible tubing from the regulator.
NOTE:
Do not disconnect the flexible tubing from the calibration adapter/splash guard.
10. Add 1 minute to the length of time determined in step 6. This is the response time for
the detector. When performing a response test, zero adjustment, or span adjustment,
gas must be applied for this length of time.
