Chapter 4: Program Setup • 35
Bump Test Section
If neither
Manual Bump Test
nor
Auto Bump Test
is selected, you will not be able to perform a
bump test. Select the box for the desired operation.
Manual Bump Test
Selected
(factory setting): A manual bump test can be performed by selecting an instrument or
instruments in the main program window and clicking
Bump Test
in the lower right corner of the
window.
Deselected
: A manual bump test cannot be performed.
Auto Bump Test
Selected
: An automatic bump test is performed only if the instrument is due for bump testing.
Deselected
(factory setting): A bump test is not automatically performed.
Fast Bump
Deselected
: The gas application during a bump test will continue for the time period defined by the
Gas Exposure Time
parameter regardless of the sensor reading(s).
Selected
(factory setting): If the gas reading for the sensor(s) being tested is within the bump test
tolerance defined in
Tolerance
below at the end of a 10 second gas application and a 10 second wait
period, the sensor(s) pass bump testing, the gas application will be stopped, and the test will move on
to the next sensor(s) or to the fresh air purge.
If the gas reading on any of the tested channels is outside of the bump test tolerance defined in
Tolerance
below at the end of the 10 second gas application and a 10 second wait period, the bump
test will fail and the next step will depend on the
Auto Cal if Bump Fails
setting.
Turning Fast on allows calibration gas to be saved when the tested sensors respond quickly and
accurately.
Consider the following scenario as an example.
•
50% LEL methane used for bump testing the combustible gas channel
•
Tolerance set to ± 50%, which means that the acceptable reading range is 25% LEL - 75% LEL
•
Fast Bump
is
Selected
The table below shows possible readings at 10 seconds and the effect on the gas application.
Table 2: Example Fast Bump Scenarios
Gas Reading After 10 Seconds of
Gas Application and a 10 Second
Wait Period
Outcome
15% LEL (-70% of 50% LEL)
• Bump test fails
• Next step depends on AUTO CAL setting
30% LEL (-40% of 50% LEL)
• Gas application stops
• Sensor passes bump testing
60% LEL (+20% of 50% LEL)
• Gas application stops
• Sensor passes bump testing
