Bender ISOMETER IRDH375, Manual

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Function
22 IRDH375_D00124_05_M_XXEN/01.2020
*) measuring principle "adaptive measuring pulse", a measuring
principle developed by Bender (European Patent: EP 0 654 673 B1).
3.4.1 Self test
A self test can be carried out manually using the TEST button or automatically.
In order to guarantee high functional reliability, the ISOMETER® IRDH375 pro-
vides comprehensive self test functions. After switching the supply voltage
on, all internal measuring functions, the components of the process control
such as data and parameter memory as well as system and earth connections
are checked using the self test functions. The progress of the self test is indi-
cated on the display by a bar graph. Depending on the conditions in the IT sys-
tem to be monitored, the self test is running for 15…20 s, then the message
"Test ok!“ appears on the LC display for approximately 2 s. Then the device re-
turns to normal measuring mode and the current measuring value is dis-
played after the expiry of the measuring time.
When a device or connection fault is found, the message "!Error!" appears on
the display, the device fault LED lights up, the relay K3 (31-32-34) switches and
the respective fault message (see table) is indicated. If such a device fault oc-
curs, a self test is started again every minute. If no more malfunction is detect-
ed, the fault message is deleted automatically and the device fault LED
extinguishes.
During operation, the self test function can be started by pressing the TEST
button (internal or external). The self test can also be started automatically
every hour or every 24 h by selecting "ISO ADVANCED: Autotest" menu.