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Thermo Fisher Scientific Alpha TDS 200 User Manual

Page 20

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Hysteresis prevents rapid contact switching if measured value is fluctuating near the set
point. Once activated, relay will not de-activate until measured value reaches set point
plus hysteresis value.

Example: Low set point is 200.0 ppm and hysteresis 100.0 ppm, relay will activate when
value is below 200.0 ppm, but will not de-activate till measured TDS value rises above
300.0 ppm.

Default hysteresis value is 5% of full scale. The hysteresis window can be set to any
value within the range 0 to 10% of full scale as shown below:

1.

Key in password “022” as per procedure in Section 5.

2.

The screen will scroll P1.0 and SP1. Press ENTER three times.

3.

The screen will scroll P1.3, HYS1, and current hysteresis value.

4.

Press ▲or ▼keys to adjust hysteresis value.

5.

Press ENTER to confirm. Press ▲and ▼keys together to return to P1.0. Press
▲and ▼keys together again, to return to TDS measurement mode.