Heath Consultants Optical Methane Detector (OM) - Manual (Page 22)

22
O
PERATING
P
ROCEDURES
Use a soft, lint free cotton towel to clean the lenses. The light
level is also affected by the alignment of the Light Source and
the Receiver. The components have been pre-aligned before they
are shipped and normally do not require realignment. However,
if the mounting brackets used to attach the system to a vehicle
distort the cross bar between Light Source and Receiver, realign-
ment may be necessary. The alignment procedure will be dis-
cussed later in this manual.
SAMPLE:
This is the normal operating mode. With the DISPLAY FUNC-
TION in this position, the display will show a one-minute time
history of the methane level. The right-most point displayed is
the most recent, and the display scrolls to the left. If no errors
are present, the left side of the display will show the
“PRESENT” methane level at the top left corner of the LCD.
This is the peak PPM level sensed in the last 1/2 second. At
the left center of the LCD the “MAXIMUM” methane PPM
level is shown. This is the maximum peak that has been
sensed and is still scrolling across the screen on the display
(approximately one-minute). At the bottom left of the LCD the
present ALARM SET POINT for the audible alarm is dis-
played. The following picture shows the OMD
TM in SAMPLE
mode when it has just begun to sense 9.3 PPM of methane.
PRESENT
9.3
MAXIMUM
9.3
SETPOINT
30.0
10 PPM
0 PPM