Instruction Manual
ExTox IMC-8/-4
BA_IMC-8_-4_e_2011-09-20.doc
Page 19 of 24
6
Operation of the Integral Measuring Concept
The operation of the control unit is described in the Instruction Manual of the Series ET-8D and
ET-4D2.
Furthermore the following remarks are valid for the additional functions and options.
Remark:
Please note that some options or their combination is not available for all IMC-Types.
ExTox is at your disposal for planning your IMC-System.
Furthermore customer specific designed IMC-Types can dispose of deviating functions,
whichare described separately in the corresponding documentation of your device.
6.1
Flow Rate Monitoring
The IMC are in general equipped with the System DDL-Module 3.0 (Art. 940285). Special types
can also be equipped with other types of flow rate monitoring. The installed type is specified in
the corresponding documentation of your device.
6.1.1
Types with DDL-Module 3.0 (Art. 940285) and 2.0 (Art. 940178)
Flow rate monitoring bases on measurement of pressure difference. The measurement of pres-
sure difference is built in the assembly group DDL-Module together with the monitoring of
housing fans. The normal flow through is appr. 30 l/h. In case the gas flow is constraint the
lower alarm level is over-run. Leakages or loosening of a hose connection leads to the entering
of leak air. The upper alarm is triggered due to the higher volume stream.
The flow rate monitoring transfers the measured value serially to the control unit. It is detailed
indicated on the display ("FLOW"). In case the alarm levels are reached the indication on the
display switches between measured value and the message "ERROR" every second. In case the
serial data link between control unit and flow rate monitoring interrupted for more than 15 s,
the message "COMERROR" is issued. A fault of control unit is indicated at the control unit.
Remark:
in the Biogas-Types the gas suction pump is switched off during some operation
phases, so that no gas flow takes place. During these planned phases the flow rate monitoring
does not show any flow through, but a system fault is correctly not triggered.
The setting of the alarm levels is done at the control unit in the extended submenu OPTIONS of
the menu System Parameter.
6.1.2
Types with Flow-Meter (Art. 940025)
The flow rate monitoring is built in a common housing together with a dust filter. At the front
side there is a text display and three keys (M, +, -). In the text display the measured gas vol-
ume stream is indicated in litre per hour (l/h) during normal measuring mode.
3
The flow rate
monitoring is equipped with an upper (MAX) and lower (MIN) alarm level; the nominal range
which should be kept is in between.
In case the gas flow is constraint the lower alarm level is over-run. Leakages or loosening of a
hose connection leads to the entering of leak air. The upper alarm is triggered due to the
higher volume stream.
Alarm Levels
For setting the alarm levels press key M until the required alarm level is indicated. By means of
the keys + and – the alarm level can newly be set. The displayed value is immediately effec-
tive.
3
For this type the indication of the volume stream in the display of the control unit is not ap-
plied.
