Chapter 7 Operation
Operating manual HE 5422 MR
27
Version 1.2
7.2
Testing function
The active test mode is indicated by the lit LED on the TEST button.
7.3
Differential pressure measurement
Fig. 7.2: Connections for differential pressure measurement
The differential pressure is internally measured and passed on to the superordinate control unit or
a display device as a 4…20 mA signal. The current output can be scaled across the adjustable
measuring range. For example:
0…30 mbar
≙
4…20 mA, 0…20 mbar
≙
4…20 mA
During normal operation, the cleaning process is started when the upper threshold "Cleaning" is ex-
ceeded and is deactivated again when the lower threshold "Cleaning" is reached. In order to exe-
cute the post cleaning during a normal deactivation process without triggering an alarm message
by falling below the "low alarm", there is a delay time of 5 minutes. The post cleaning threshold has
to be reached before these 5 minutes have passed, as the low alarm will else be triggered.
1.
Press the TEST button in order to execute a measuring hose cleaning cycle.
P +
Raw gas
P -
Pure gas
Blowing air
