Installation, Operating & Maintenance Instructions
Series 651 DN 320-400 (I.D. 12“ - 16”), Logic
VAT Vakuumventile AG, CH-9469 Haag, Switzerland
Tel +41 81 771 61 61 Fax +41 81 771 48 30 [email protected] www.vatvalve.com
267736ED
2008-02-26
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3.10.1 Operation with 2 sensors
[applicable with 651 . . - . . . E - . . . . version only]
If 2 sensor operation is enabled, changeover between the sensors is done automatically during pressure control. For
configuration refer to chapter «Setup procedure». We recommend a ratio of 10:1 between the pressure gauges. Max. ratio
is 100:1. It is required that the high range pressure gauge is connected to sensor 1 input and the low range pressure
gauge to the sensor 2 input.
Between 90 and 100% of the low range sensor full scale, the low range sensor is phased out while high range sensor is
phased in. This maintains a functional response behavior in case of small calibration errors between the two sensors. The
pressure output in this range is a blend between both sensors.
For monitoring purpose each sensor signal may be read out individually.
Note: Make sure that both sensors are calibrated.
Note: Do not close optional gauge isolation valves during the transition phase between the sensors.