Determining response time – RKI Instruments 65-2405RK-04 User Manual
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16 • 65-2405RK-04 Combustible Gas Transmitter
If an application is not very demanding, for example detection in a clean, temperature
controlled environment where combustible gas is not normally present and calibration
adjustments are minimal at calibration, then a calibration frequency of every 6 months is
adequate.
If an application is very demanding, for example if combustible gas is present often and in
significant concentrations or the environment is not well controlled, then more frequent
calibration than every 3 months may be necessary. If potential catalyst poisons are known
or likely to be present, more frequent calibration than every 3 months will be necessary.
Determining Response Time
Since the detector junction box is installed remotely from the amplifier, the response time
of the detector will depend on the length of flexible tubing that is attached to the
calibration cup/splash guard. To determine the response time based on the length of
tubing connected:
1.
Place the controller into its calibration mode or disable external alarms.
2.
Note the current gas reading displayed at the controller.
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 cup/splash guard to connect the
regulator to the calibration cup.
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 cup/splash guard’s flexible tubing from the regulator.
NOTE:
Do not disconnect the flexible tubing from the calibration cup/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.