Chapter 6: Changing SDM-3R Parameters for Standalone Operation • 71
Consider the following scenario as an example.
•
50% LEL methane used for bump testing the combustible gas channel
•
Tolerance
set to ± 50% LEL, which means that the acceptable reading range is 25% LEL - 75%
LEL
•
Fast Bump
selected
The table below shows possible readings after the 10 second gas application and the 10 second
stabilization period and the effect on the gas application.
Auto Cal If Bump Fails (for bump only)
Selected
(factory setting): The docking station automatically performs a calibration if a bump test
fails.
Deselected
: The docking station will not automatically perform a calibration if a bump test fails.
Alarm Check (for bump and calibration)
Selected
(factory setting): A GX-3R (Pro) LED and buzzer test is done at the end of the bump test or
calibration. The LEDs turn on for a few seconds, the buzzer sounds, and the SDM-3R determines if
these actions were completed successfully.
Deselected
: An LED and buzzer test is not done at the end of a bump test or calibration.
Auto bump if past due (for bump only)
Selected
: If the connected GX-3R (Pro) is due for a bump test, the SDM-3R automatically performs a
bump test on all channels immediately after the GX-3R (Pro) is connected.
Deselected
(factory setting): An automatic bump test is not performed, even if the GX-3R (Pro) is due
for one.
Table 4: Example Fast Bump Scenarios
Gas Reading After 10 Seconds of Gas
Application and a 10 Second
Stabilization Period
Outcome
15% LEL (-70% of 50% LEL)
• Bump test fails
• Next step determined by
Auto Cal If Bump Fails
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
80% LEL (+60% of 50% LEL)
• Bump test fails
• Next step determined by
Auto Cal If Bump Fails
setting
