Calibration – RKI Instruments 65-2497RK User Manual
Page 15
65-2494RK/65-2497RK Oxygen Detector • 11
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 oxygen detector. It includes procedures to
prepare for calibration, set the fresh air reading, set the zero reading, and return to normal
operation. It describes calibration 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
1.
Screw the calibration cup onto the bottom of the oxygen detector.
2.
Screw the regulator into the zero air calibration cylinder. Make sure the regulator is
off. It is off when the on/off knob is turned all the way clockwise.
3.
Use the sample tubing to connect the regulator to the calibration cup.
NOTE:
If you can verify that the oxygen detector is in a fresh air environment, you do
not need to apply zero air to the detector before adjusting the fresh air reading.
4.
Put the controller into its calibration program. See the controller operator’s manual
for instructions to enter the calibration program.
Setting the Fresh Air Reading
1.
Follow the instructions in the controller operator’s manual for setting the fresh air
reading.
2.
When the instructions call for applying zero air to the detector, turn the regulator’s
on/off knob counterclockwise to open it. Gas will begin to flow.
3.
Allow the gas to flow for two minutes.
4.
Set the fresh air reading according to the controller operator’s manual.
5.
Turn the regulator’s on/off knob clockwise to close it.
6.
Unscrew the regulator from the zero air calibration cylinder. Leave the sample tubing
connected to the regulator and the calibration cup.
NOTE:
Depending on the size of your zero air cylinder, it is possible that you will have a
different regulator for the zero air cylinder and the nitrogen gas cylinder. If
necessary to fit the nitrogen gas cylinder, change the regulator.
Setting the Zero Reading
1.
Screw the regulator into the 100% nitrogen calibration cylinder. Make sure the
regulator is off. It is off when the on/off knob is turned all the way clockwise.
2.
Follow the directions in the controller operator’s manual for setting the zero reading.
3.
When the directions call for exposing the detector to gas, turn the regulator’s on/off
knob counterclockwise to open it. Gas will begin to flow.