Calibration frequency, Calibration – RKI Instruments 65-2399RK-CH4 User Manual

Page 19

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65-2399RK-CH4 Combustible Gas Transmitter • 15

NOTE:

When a transmitter is first powered up with a new amplifier, the initial output
may be either high or below zero depending on the setting of the zero pot. Be
sure to make arrangements so that this does not cause unwanted alarms.

10. Turn on power to the controller.

11. Turn on the controller and place it into normal operation.

NOTE:

When first powered up, the transmitter will enter about a one minute period
when the 4-20 mA output is stabilizing and may be above the controller alarm
points or well below zero momentarily. RKI controllers have a one minute
warmup period when the controller does not display any gas reading or give any
alarm indication. The methane transmitter’s 4-20 mA signal should be stable by
the time the controller’s warmup period is over.

12. Allow the transmitter to warm-up for 5 minutes.

13. Calibrate the transmitter as described in “Calibration” on page 15 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 methane 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.

Calibration

This section describes how to calibrate the methane 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.

DETECTOR “W”

WHT

DETECTOR “G”

GREEN

DETECTOR “B”

BLK

Table 5:Reconnecting the CH

4

%Vol.

Detector to the Amplifier

Amplifier Detector

Terminal Strip

Detector Lead

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