16 • Setting the Operational Parameters in Edit Mode
Consider the following scenario as an example.
•
50% LEL methane used for bump testing the combustible gas channel
•
GAS bump test parameter set to 20 seconds
•
Tolerance set to ± F50%, which means that the acceptable reading range is 25%
LEL - 75% LEL
The table below shows possible readings at 10 seconds and the effect on the gas
application.
Automatic Calibration (CAL)
Automatic calibration only applies to bump testing. It can be set to on or off. If it is set
to on, then the docking station will automatically perform a calibration if a bump test
fails.
Turning on the SDM-2009 with an Instrument
Do the following to turn on the SDM-2009 and establish a connection with an
instrument:
1. Confirm that the AC adapter is connected to the SDM-2009 and to an AC wall
socket.
2. Press and hold the SDM-2009’s POWER button. The LEDs will turn amber.
3. When the BUMP
and CAL
LEDs turn off, release the POWER button.
4. The COPY LED will be steadily on or off and the CHARGE LED will be blinking
green if the SDM-2009 is operating properly or solid red if there is a system
failure. The amount of free memory in the SDM-2009 will dictate the condition
of the COPY LED (see “Available Memory in the SDM-2009” on page 39).
5. Install an instrument into the instrument cradle.
6. Press and hold the POWER MODE button on the instrument until you hear a
beep, then release it. The instrument will begin its power up sequence (see
Table 4: Example Fast Bump Scenarios
Gas Reading 10 Seconds
Into Fast Bump
Outcome
15% LEL (-70% of 50% LEL)
• Gas application continues for the full 20 seconds
• Pass/fail determined at end of 20 seconds
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)
• Gas application continues for the full 20 seconds
• Pass/fail determined at end of 20 seconds