RKI Instruments Digester Gas Monitor User Manual
Page 73
Digester Gas Monitor Operator’s Manual
Viewing Maximum Spans • 67
the detector was exposed to 50 %LEL gas. If the maximum span value is close to the
calibration gas value, for example if it is 53 %LEL for a 0 - 100 %LEL channel when 50
%LEL calibration gas is used, the sensor should be replaced soon.
To make the maximum span values as meaningful as possible, there is a limit to how
much remaining adjustment the screen will indicate. The maximum remaining adjustment
that will be shown for any channel is 3 times the calibration gas concentration even if the
Digester Gas Monitor could have adjusted it higher. For example, if 50% LEL gas was
used to calibrate a 0 - 100 % LEL channel, the highest maximum span value that will be
displayed is 150 %LEL. If the maximum span adjustment possible for a channel is more
than 3 times the calibration gas value, a “+” sign will be displayed next to the maximum
span value.
The maximum span values that are displayed are from the most recent successful
calibration for each channel. So they are most useful soon after a calibration is performed.
If an extended period of time, for example 2 or 3 months, has passed since the last
successful calibration on a particular channel, the maximum span value for that channel
may no longer be accurate.
To view the maximum span values, do the following:
1.
Navigate to the Select Operation Screen as described in “Entering Calibration Mode”
on page 62 or navigate to the Select Operation Screen after performing a calibration.
2.
Use the UP/YES or DOWN/NO button to display VIEW MAX SPANS on the Select
Operation Screen.
3.
Press and hold the ENTER button to display the maximum spans. In the example
below, channels 1, 2, 3, and 4 are active.
4.
Release the ENTER button to return to the Select Operation screen.
5.
Press and release the ESCAPE button to return to the initial Calibration Mode Screen
that says You Have Entered the CALIBRATION Menu... and then press and release
the DOWN/NO button to exit Calibration Mode and return to Standby Mode.
Select Operation
VIEW MAX SPANS
UP / DN then ENT / ESC
1: METHANE 0+%VOL
2: OXYGEN 49.2 %VOL
3: CO2 0.0+%VOL
4: H2S 0 ppm