CODEL Energy Tech 401, Installation, Operation And Maintenance Manual

Page: 47 / 131

Section 4
Commissioning
Issue: A Revision: 1 Date: 24/07/19 Ref: 100606
Page: 47
Detector Levels 4.6
The gain of the detector signals is set in two locations :

In the receiver : two potentiometers set the gain - see Receiver Gain
Adjustment.

In the signal processor : trim potentiometers adjust the level of the D1 and D2
signals before they enter the microprocessor -see Signal Processor Gain
Adjustment.
It is essential that the alignment procedure has been conducted and a maximum
detector signal obtained before attempting to optimise the detector levels.
To give an optimum signal-to-noise ratio, the detector levels must be maximised.
For the best signal-to-noise ratio, the gain of the detector signals within the
receiver must be set to a maximum, without saturating. The gains will have been
set by CODEL at a pathlength of 2m. If the pathlength is above 4m or below
1.5m, this adjustment may be necessary to optimise the detector levels. If the
pathlength is within this bank, this section may be ignored unless there is
insufficient or too much gain.

Enter the Set-up mode, CALIBRATE OPTION-SET DETECTORS, and display the
value of D2/D1.
 Loosen the cable gland and remove the end cap from the receiver body, letting
the cable slip through the gland.

The receiver can now be accessed as shown in Figure 13.
4.6.1 Receiver Gain
Adjustment