Heathus OMD, Manual

Page: 23 / 60

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PPM RANGE:
Consecutively pressing the PPM RANGE button allows the
formatting of the display with full-scale settings of 10, 30, or
90 PPM. The ranges will actually display to slightly higher
values up to 13, 40, and 120 PPM. The PPM RANGE button
changes the scale at all times that the time history of the
methane level is displayed, including DISPLAY HOLD. The
digital readout of gas concentrations on the left side of the
display will indicate the gas concentrations over 200 PPM
independent of the setting of the PPM RANGE button. The
PPM RANGE button only changes the amplification of the
one-minute history on the right hand side of the LCD.
The “90” range is the power up default position indicated by
the line under the number 90. Press the button to change the
range from 90 to 30 to 10 and back to 90 again, as indicated by
the direction of the arrow.
Following are some examples of the same size leak being
displayed in each of the three ranges.
PRESENT
0.0
MAXIMUM
16.6
SETPOINT
30.0
90 PPM
0 PPM
Here is a 16.6-PPM leak displayed in the 90-PPM range.
O
PERATING
P
ROCEDURES