RKI Instruments M2 Series - Manual (Page 50)

45 M2 Transmitter Operator’s Manual
oxygen reading will be on the bottom display line.
To skip adjusting the fresh air reading, press and release the DOWN/NO button. The
display will indicate ZERO w/Cal Gas?. Skip to the next section, “Adjusting the Zero
Setting”.
4. Screw the zero air cylinder into the fixed flow regulator.
5. Turn the regulator knob counterclockwise to open the regulator.
6. Allow zero air to flow for 2 minutes. If the oxygen concentration in the area is less
than 20.9, the reading should stabilize after 2 minutes.
7. Turn the regulator knob clockwise to close the regulator.
8. Unscrew the zero air cylinder from the fixed flow regulator leaving the calibration cup
on the detector. The M2 will continue to display the maximum gas response on the
display and retain the response level in its memory.
9. Press and release the ENTER button. The M2 will perform a fresh air adjustment and
the display will indicate ZERO w/Cal Gas?.
NOTE: If the fresh air adjustment fails, see “Troubleshooting” on page 38 for
recommended actions.
Adjusting the Zero Setting
1. If you want to continue with adjusting the zero setting, press and release the UP/YES
button. APPLY will alternate with ZERO Gas on the top display line and the current
oxygen reading will be on the bottom display line.
If you want to skip adjusting the zero reading, press and release the DOWN/NO
button. The display will indicate Leaving Cal Mode and the M2 will return to normal
operation.
2. Screw the 100% nitrogen gas cylinder into the fixed flow regulator.
3. Turn the regulator knob counterclockwise to open the regulator.
4. Allow gas to flow for 2 minutes. The gas reading should be stable after 2 minutes.
5. Turn the regulator knob clockwise to close the regulator.
6. Unscrew the nitrogen cylinder from the fixed flow regulator and unscrew the
calibration cup from the detector. The M2 will continue to display the minimum gas
response on the display and retain the response level in its memory.
7. Adjust the oxygen reading up or down to match the 100% nitrogen cylinder oxygen
concentration of 0 by using the UP/YES and DOWN/NO buttons.
NOTE: If a cylinder other than a 100% nitrogen (0% oxygen) cylinder is used to set the
zero reading, such as a cylinder with 12% oxygen, set the zero reading to match
the cylinder’s oxygen concentration.
8. Press and release the ENTER button. The M2 will perform a zero operation. The
display will indicate ZERO Gas PASS for a few seconds, then indicate ZERO Gas
SAVED
before indicating Leaving CAL Mode for a few seconds.
NOTE: If the zero adjustment fails, see “Troubleshooting” on page 38 for
recommended actions.