STATUS SCIENTIFIC CONTROLS
FGD3 Infrared Gas Detector Heads
TD06/024
Issue:
7
Change Note:
1904
Page 17
5.2.2
C: 2 - Span Sensor
This is a calibration feature. It allows the instrument to determine the sensor output
when it is exposed to a know concentration of gas.
•
Apply a known concentration of gas to the sensor inlet and allow enough
time for the sensor to respond.
•
Select menu mode
C: 2
(refer to section 5.2) and press ENTER.
•
Using the UP and DOWN buttons, adjust the displayed reading so that it
matches the calibration gas concentration.
•
Press ENTER to perform the SPAN calibration. Pressing MENU instead of
ENTER aborts the calibration (the SPAN factor will still be displayed on exit).
•
Press MENU
– the display will show the SPAN factor for the instrument
before returning to its standard mode of operation.
The SPAN factor should be recorded on any calibration certificates completed.
5.2.2.1
Suggested calibration gas levels.
Hydrocarbon sensor:
(refer to section 1)
20 to 50%LEL Methane
20 to 50%LEL Propane
20 to 50%LEL Pentane
Carbon Dioxide sensor
1 to 2% vol. Carbon Dioxide
5.2.2.2
Calibration Factors
During the ZERO sensor and SPAN sensor calibrations a factor is displayed that
allows the calibration personnel to have confidence with their calibration.
The ideal ZERO and SPAN factors are as follows:-
Sensor
Factor
MIN
TYP
MAX
HC
Zero
TBA
1.850
TBA
HC
(Pentane)
Span
TBA
0.660
TBA
HC
(Methane)
Span
TBA
0.140
TBA
Carbon Dioxide
Zero
TBA
0.75
TBA
Span
TBA
0.42
TBA
