Gain Adjustment
The receiver (Rx) gain has two stages. The first, adjustable via the keypad, is in
the receiver head and consists of a low (x1) or high (x10) setting. The second
stage is a variable gain within the signal processor (SP) and is adjustable using
VR1 (VR2 is for Dt level). After the equipment has been aligned, the gain may
be set as follows :
• Enter the SET-UP mode (mode 5) CALIBRATE menu - Set Rx
Gain option.
• Rx gain can be scrolled HIGH or LOW by the UP and DOWN
arrow keys and entered by the ENTER key.
• SP gain is adjusted using VR1.
• View the detector levels from set detectors within the CALIBRATE
menu and progressively increase the gain until a detector level
between 10,000 and 20,000 is obtained.
Note : Always try the RX gain HIGH setting first. If the caption ‘Rx
Det Saturated’ appears, then switch to Rx LOW to remove the
saturation.
! Should the instrument be commissioned when a high opacity is
present in the duct, reduce the level of Dr to between about
6,000 and 10,000. This is to prevent overloading if the opacity
level reduces.
• Press ENTER to return to the CALIBRATE sub mode. Press
MODE to return to the unit to operating condition, i.e. MODE 1.
Basic Calibration
Before the instrument can calculate the correct opacity within the duct, a basic
calibration routine must be conducted.
Select the set up mode and conduct a basic calibration, detailed below. Section
4.9. Calibrate contains a fuller description. Record the calibration data in the
table at 3.8. Calibration Data.
To Next Page
Loading...
Need help?
General
