Span Adjustment - HACH LANGE astroTOC UV Manuel D'utilisation De Base

Figure 19 Adjust the zero potentiometer on the 8000 controller PCB
1 Contrast adjustment
2 LK1-IR range selection (OUT=0-1000 ppm,
IN=0-10000 ppm)

3 Span adjustment

4 TP4-IR voltage 0.25V-4.75 V (at sea level only)
5 Zero adjustment
6 TP3 Analog ground (Ø V)
7 TP1-INT output
8 TP5-SIG IN (input signal from IR bench)
Span adjustment
1. Connect the appropriate span gas (1000 ppm or 10000 ppm) to the IR manifold and let it flow for
10 minutes at 200 cc/minute until the reading is stable.
2. When the reading is stable, adjust the span potentiometer to read the approximate CO
(1000 or 10000 ppm).
3. After the span adjustment is completed, examine the zero adjustment again. The span and zero
adjustments interact. Adjust the zero setting and the span setting back and forth as necessary to
get correct last adjustments.
Note: Noise can cause minor fluctuations in the readings. If the fluctuations bracket the wanted values, the
readings are acceptable.
4. If the span gas does not yield 1000 ppm ±5 ppm or 10000 ppm ±50 ppm, make sure that the
LK1 jumper position is correct. If necessary, contact the manufacturer.
9 LK2-IN-AGC setup
10 LK5-LK8-IN
11 TP2-Source voltage 1.7 V
12 Source voltage adjustment to 1.7 V
13 LK4-OUT (stepper inputs)
14 TP6-Digital 0 V
15 LK3-EPROM
ppm
2
English 37