STATUS SCIENTIFIC CONTROLS
FGD3 Infrared Gas Detector Heads
TD06/024
Issue:
7
Change Note:
1904
Page 13
5 Calibration and Menu System
The recommended calibration interval is 6 months. Under no circumstances should it
exceed 12 months.
Important
Whenever the menu system is entered the instrument will cease to indicate the
gas levels that it detects to the control unit. However normal operation is always
returned following a period of keypad inactivity (or when the menu system is
exited).
In order to gain access to the calibration switches and test points, release the screw
situated between the letters A and T of the chrome STATUS label on the Detector
Head front panel. The screw does not need to be completely removed, only release it
far enough so that the STATUS label can rotate revealing the calibration switches and
test points. The buttons and test points are designated as follows:
The keypad has the following functionality:
Button
Function
Alternate Function
MENU
Open / Close Menu
PASSword
UP
Next / Increase
1
DOWN
Previous / Decrease
2
ENTER
Accept selection
3
Note:
Where possible, disable the channel at the control unit so that the calibration feature
used does not cause an alarm condition to be indicated. Refer to control unit
manufacturers’ user manual for further details.
5.1.1
Calibration Gas Flow Rates
The infrared sensors are known to be sensitive to pressure transients and therefore it
is important that the flow rate of gas into the sensor housing is not excessive during
calibrations. Care must also be taken to ensure the exhaust from the sensor housing is
not restricted. The recommended flow rate of calibration gases is 500 - 750cc/min.
r
r
V
UP DOWN TP1 TP2 ENTER MENU
+
-
V
