Heath Consultants Remote Methane Leak Detector (RML) - Manual (Page 21)

Press the UP button to return to the beginning of the SELF-TEST and
refer to the next section: Calibration Override.
7. Press the UP button. This will initiate the calibration sweep of the laser
wavelength. This takes about 45 seconds to complete and you will notice that
the gas concentration readings will go up and down.
8. When the OK icon is once again displayed, the instrument has passed the laser
calibration.
a. If the RETRY icon is displayed the instrument failed the calibration.
Press the UP button to return to the beginning of the self-test.
9. Press the UP button to acknowledge.
10. Press the SELECT button to scroll back to the run display.
What if the instrument failed the Self-Test and Calibration? Most often, the cause is due
to the transceiver not being properly positioned in the case or the laser wavelength has
drifted. Make sure the unit is in its proper position, all the way down, and flat. Note the
gas concentration. It is typically about 1100 ppm-m, but must be between 500 and 2000
ppm-m. After rechecking the above, repeat the Self-Test and Calibration procedure
above.
Calibration Override
Should the unit fail at step 6 due to initial low readings perform the following actions:
1. Ensure the instrument is still in the Self-Test menu from step 6 above.
2. Override the normal Self-Test function by pressing the DMD button. This will
force the laser calibration sweep.
3. At the end of the first sweep, OK will be displayed. Press the UP arrow key again
to restart the sweep.
4. At the end of this sweep, Self-Test OK will be displayed. Press the UP arrow and
then SELECT to exit the Self-Test menu.
a. If it fails, it will show RETRY, and the unit is not functioning properly.
Contact HEATH for assistance.
**Note**
Laser wavelength drift is a normal characteristic of the RMLD. Normally the rate of drift
is low and will not affect the Self-Test if performed on a regular basis. If the initial
reading is low when placed in the case, and requires the use of the calibration override to
force it through calibration, then the laser calibration was previously off. Survey work
conducted with a unit out of calibration may need to be redone. If initial concentration
readings are low on a regular basis such that the override must be always used, contact
HEATH for assistance.
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101515-0 RMLD MANUAL REV E