Adc Timing Adjustment; Reaction Bath Temperature Adjustment; Adc Timing Waveform Specification - Hitachi 902 Service Manual

14.1.3 ADC Timing Adjustment

Adjust the ADC timing in the following procedure.
< Adjusting procedure >
The board to be adjusted is the DI board (1st board from the right in circuit board rack).
(1) Measure voltage across check pins TP1-TP2 (G) (DI board) and across TP14-GND (LOG
AMP board) using a synchroscope.
(2) Rotate the reaction disk using the mechanism check operation of the instrument check
program, and adjust the measured waveform using trimmer VR1 to obtain the timing
shown in Fig. 14-1.
NOTE: It may take 1 or 2 minutes until the LOG AMP output waveform appears.
LOG output
* Terminals:
Between TP14 and AG
One shot in DI
* Terminals:
Between TP1 and DG
In AD converting operation, a time period of 13 ms is
taken from the rise of ADC start signal. This period of
time should correspond to the flat section of LOG
output.

14.1.4 Reaction Bath Temperature Adjustment

Adjust reaction bath temperature in the following procedure.
< Adjusting procedure >
(1) Connect a tester across CP5 and SG of EMIO100 board.
(2) Turn power on and put the instrument in standby.
26 ms
13 ms
A/D
Fig. 14-1 ADC Timing Waveform Specification
±4 ms
-4 +4
15 ms or more (flat section)
14 - 3
LOG output:
Across LOG AMP board TP14-GND
Across DI board TP1-TP2
(adjust with VR1)