RKI Instruments M2 Series - Manual (Page 48)

43 M2 Transmitter Operator’s Manual
6. Unscrew the calibration gas cylinder from the fixed flow regulator and unscrew the
calibration cup from the detector. For an ESM-01 detector, pull the calibration cup off
of the ESM-01 sensor and screw the splashguard back onto the detector housing cap.
The M2 will continue to display the maximum gas response on the display and retain
the response level in its memory.
7. Adjust the gas reading up or down to match the calibration gas cylinder concentration
by using the UP/YES and DOWN/NO buttons, then press and release the ENTER
button.
8. The M2 will perform a span operation. The display will indicate SPAN Gas PASS for
a few seconds, then indicate SPAN Gas SAVED before indicating Leaving CAL Mode
for a few seconds.
NOTE: If the span adjustment fails, see “Troubleshooting” on page 38 for
recommended actions.
9. The display will now alternate between the normal operation screen and the message
REMOVE CAL GAS
for 1 minute. If the calibration gas has not been removed from
the detector, remove it now to avoid unwanted alarms.
During this 1 minute period, the signal output will remain fixed at 3.5 mA and the
relays will remain in their non-alarm state to avoid unwanted alarms while the
calibration gas clears from the detector. At the end of the 1 minute period, the
REMOVE CAL GAS
message will stop appearing and the M2 will return to normal
operation.
10. Store the components of the calibration kit in a safe place.
Calibration, Oxygen Version
This section describes how to calibrate the oxygen version of the M2. It includes
procedures to prepare for calibration, enter Calibration Mode, set the fresh air (span)
reading, set the zero reading, and return to normal operation.
WARNING: The M2 is not an active gas monitoring device during the calibration
procedure. The 4-20 mA output signal will “freeze” at 17.4 mA and all
relays will remain in their non-alarm state while the M2 is in Calibration
Mode. The output signal will not indicate current readings and the relays
will not resume operating normally until the M2 is in normal operation
again.
Preparing for Calibration
NOTE: The following procedure assumes the use of a calibration kit which includes a
zero air (20.9% oxygen) calibration cylinder to set the fresh air reading, a 100%
nitrogen (0% oxygen) calibration gas cylinder to set the zero reading, a fixed
flow regulator with an on/off knob, a calibration cup, and a short piece of
sample tubing to connect the regulator to the calibration cup. A cylinder with
up to an 18% oxygen concentration may be used instead of a 100% nitrogen
cylinder to set the zero reading.