Service manual

Section - VI Reading Station BT3000 PLUS Rev. 0, Soft Ver. 8 Page 11 of 12
The calibration of each channel is performed in reference conditions (usually at
the factory). The following requirements must be observed for the calibration
procedures: clean and transparent cuvette filled with distilled water, new halogen
lamp, and sufficient warm up time. The diagnostic program can be used for
verification and any correction, if necessary. Each channel must generate an
output signal between 4 Volts and 10 Volts (theoretical). The voltage values are
not visible in the diagnostic program, but the integration values are equivalent if
the conversion factors are assumed as reference. In practice, the integration
values should be between 14,000 and 28,000 points for all of the channels. This
range takes into account the tolerances necessary for different lots of lamps and
their related exhaustion. In addition an external photodiode acting as Reference
Channel (Figure 6-2) has a range (unadjustable) of 3000 to 16000 points.
Refer to the diagram of "10-Channel Photodiode Array Photometer" below.
SEMI-REFLECTING
MIRRORS
LIGHT-BEAM
INPUT
REFLECTED
LIGHT
INTERFERENCE
FILTERS
PHOTODIODE
DETECTORS
10-Channel Photodiode Array Photometer
Figure 6-7