70 • Chapter 6: Changing SDM-3R Parameters for Standalone Operation
AIR Flush (for bump and calibration)
The pre-sample flush time is the length of time that the SDM-3R draws air through the AIR fitting
before performing an air adjust operation. It can be set from
15
to
120
seconds. The factory setting for
bump test and calibration is
15
seconds.
NOTE:
If the GX-3R (Pro) was not on for 40 seconds before the bump test was initiated, air
will flow until the GX-3R (Pro) has been on for 40 seconds regardless of the AIR
Flush setting.
GAS (for bump and calibration)
The gas sample time is the length of time that the SDM-3R draws calibration gas through each of the
gas fittings. It can be set from
20
to
120
seconds. The factory setting for bump test is
20
seconds. The
factory setting for calibration is
60
seconds.
AIR Purge (for bump and calibration)
The post-sample purge time is the length of time that the SDM-3R draws air through the AIR fitting to
purge calibration gas from the system. It can be set from
5
to
120
seconds. The factory setting is
15
seconds.
Tolerance (for bump only)
The bump test check tolerance determines how close the GX-3R (Pro) gas reading must be to the
calibration gas concentration for each channel during a bump test in order to pass the bump test. It is
defined as a percentage of the calibration gas concentration. The amount that the GX-3R (Pro) gas
reading differs from the calibration gas concentration must be equal to or less than this percentage of
the calibration gas concentration. For example, if the tolerance is set to 50%, and the %LEL calibration
gas concentration is 50% LEL, then the bump test gas reading for the LEL channel on the GX-3R (Pro)
must be 50% LEL ± 25% LEL.
The available options are:
10%
,
20%
,
30%
,
40%
,
50%
(factory setting).
Fast Bump (for bump only)
Turning
Fast Bump
on allows calibration gas to be saved when the tested sensors respond quickly and
accurately.
If
Fast Bump
is
deselected
, the gas application during a bump test continues for the time period
defined by the
GAS
bump test parameter regardless of the sensor reading(s).
If
Fast Bump
is
selected
(factory setting) and the gas reading for the sensor(s) being tested is above
the lower tolerance and below the upper tolerance within a 10 second gas application and a 10 second
stabilization period, the sensor(s) pass bump testing, the gas application is stopped, and the test moves
on to the next sensor(s) or to the fresh air purge.
If
Fast Bump
is
selected
(factory setting) and the gas reading on any of the tested channels is below
the lower tolerance or above the upper tolerance within a 10 second gas application and a 10 second
stabilization period, the bump test fails. The next step depends on the
Auto Cal If Bump Fails
setting.
