RKI Instruments 65-2422RK-05 - Manual (Page 18)

14 • 65-2422RK-05 H
2
S Transmitter
CAUTION: Allow the replacement detector to warm up for 5 minutes before you continue with
the next step.
11. Calibrate the replacement detector as described in the Calibration section of this
manual.
12. Secure the junction box cover to the junction box.
Calibration Frequency
Although there is no particular calibration frequency that is correct for all applications, a
calibration frequency of every 3 months is adequate for most H
2
S transmitter applications.
Unless experience in a particular application dictates otherwise, RKI Instruments, Inc.
recommends a calibration frequency of every 3 months for the H
2
S transmitter.
If an application is not very demanding, for example detection in a clean, temperature
controlled environment, 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 the environment is not well controlled,
then more frequent calibration than every 3 months may be necessary.
Calibration
This section describes how to calibrate the H
2
S transmitter. It includes procedures to
prepare for calibration, set the zero reading, set the response reading, and return to
normal operation. It describes the test using a calibration kit that includes a calibration
cup, calibration gas, sample tubing, and a fixed flow regulator with an on/off knob. RKI
Instruments, Inc. recommends using a 0.5 LPM (liters per minute) fixed flow regulator.
Preparing for Calibration
NOTE: Calibrating the H
2
S transmitter may cause alarms. Be sure to put the controller
into its calibration program or disable external alarms before calibration.
1. Screw the calibration cup onto the bottom of the H
2
S detector.
2. Screw the regulator into the zero air calibration cylinder.
3. Use the sample tubing to connect the fixed flow regulator to the calibration cup.
4. Set a voltmeter to measure in the millivolt (mV) range.
WARNING: Do not remove the sensor cap or junction box cover while the circuits are
energized unless the area is determined to be non-hazardous. Keep the
sensor cap and junction box cover tightly closed during operation.
5. 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-.