GESTRA LRR 1-52, Руководство по установке

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6
Important Notes
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Glossary
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Temperature compensation
The electrical conductivity changes as the temperature falls or rises. To obtain meaningful readings it
is therefore necessary that the measurements are based on the reference temperature of 25 °C and
that the measured conductivity values are corrected by the temperature coefficient factor tC.
Cell constant and correction factor
The cell constant is a geometric quantity characteristic of the conductivity electrode and is taken into
account when calculating the conductivity. However, in the course of time this constant may chance,
e. g. due to dirt deposits accumulated on the measuring electrode. Deviations can be compensated by
changing the correction factor C LRG.
Purging of the continuous blowdown valve
To prevent the continuous blowdown valve from getting stuck the valve can be rinsed automatically.
At regular intervals (purging interval Ti) the continuous blowdown valve is motored into the open po-
sition and rinsed (purging time Sd). After purging the valves is motored back into the required control
position.
Stand-by operation (conductivity control)
To avoid loss of water, the continuous blowdown control and the programme-controlled intermittent
boiler blowdown (if activated) can be de-activated during stand-by operation or when the burner is
switched off. An external control command will be triggered and, as a result, the continuous blow-
down valve will be closed. During stand-by operation the MIN/MAX limits and the monitoring function
remain active.
After the equipment switches back to normal operation, the continuous blowdown valve is motored
back into control position. In addition an intermittent blowdown pulse is triggered off (provided that
automatic intermittent boiler blowdown has been activated and an interval period and pulse duration
has been set).