RKI Instruments 65-2390RK - Manual (Page 17)

65-2390RK Combustible Gas Transmitter • 13
CAUTION: Allow the detector to warm up for 5 minutes before you continue with the next step.
14. Calibrate the combustible gas transmitter as described in “Calibration” on page 13 of
this manual.
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 combustible gas
transmitter applications. Unless experience in a particular application dictates otherwise,
RKI Instruments, Inc. recommends a calibration frequency of every 6 months for the
infrared combustible gas transmitter.
If an application is not very demanding, for example detection in a clean, temperature
controlled environment where the toxic or combustible target gas is not normally present,
and 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.
Calibration
This section describes how to calibrate the combustible gas transmitter. It includes
procedures to prepare for calibration, set the zero reading, set the response reading, and
return to normal operation.
WARNING: The controller is not an active gas monitoring device during the calibration
procedure.
NOTE: The following procedure assumes the use of a calibration kit which includes a
calibration gas cylinder, a 0.5 LPM fixed flow regulator with an on/off knob, a
calibration cup for the detector, and a short piece of sample tubing to connect the
regulator to the calibration cup.
Preparing for Calibration
1. Screw the calibration cup onto the bottom of the combustible gas detector.
2. Use the sample tubing that comes with the calibration kit to connect the regulator to
the calibration cup.
3. Set a voltmeter to measure in the millivolt (mV) range.
4. Remove the junction box cover, then plug the voltmeter leads into the test points on
the amplifier.
Plug the positive lead into the test point labeled TP+; plug the negative lead into the
test point labeled TP-.