25
Calibration procedure
1) Connect a mV source to thermocouple input.
2) Connect a DVM to TP1.
3) Set mV source to give a reading of 3.00 volts at TP1.
(This should correspond to 300°C input = 12.2mV).
4) Connect DVM TP2.
5) Adjust VR1 to give reading of -2.81 volts at TP2.
6) Connect DVM to TP3.
7) Adjust VR2 to give reading of +4.14 volts at TP2.
8) Adjust VR3 so that it is in a position approximately half way between the positions
where LEDs 2 and 5 and LEDs 1 and 5 are illuminated.
PCB calibration is now complete and a check of binary output can be made using Table 1.
Air flow adjustment is dealt with in 'setting Up Procedure'.
taBle 1
TEMP TEMP Mv FLOW
VALVE ENERGISED/WIRE COLOUR
°C
°F
litre/min
1
2
3
4
5
Brown
Red
Orange Yellow
Green
25
77
1.0
29.0
X
X
X
50
122
2.0
29.0
X
X
X
X
75
167
3.1
28.5
X
X
X
100
212
4.1
28.0
X
X
X
125
257
5.1
27.5
X
X
150
302
6.1
21.0
X
X
X
X
175
347
7.1
20.5
X
X
X
200
392
8.1
20.0
X
X
X
225
437
9.1
19.5
X
X
250
482
10.2
19.5
X
X
X
280
536
11.4
19.0
X
X
310
590
12.6
18.5
X
X
340
644
13.9
18.0
X
370
698
15.1
12.5
X
X
X
X
430
806
17.7
12.0
X
X
X
490
914
20.2
11.5
X
X
X
550
1022
22.8
11.0
X
X
610
1130
25.3
11.0
X
X
X
Flow rate litre/min
0.5
1.0
1.5
9.5
18.0
