sauermann ECM Guide Rapide page 2

Quick start guide
English
The ECM electric contact pressure controllers are the result of a long experience in
the research and manufacture of measuring and control instruments.
They are designed to combine the inherent reliability and accuracy of the liquid
column manometer with electronic switching.
The Sauermann ECM electric contact pressure controllers excel where it is necessary
to monitor small variations in low pressures of air or gas.
1 Operation
The ECM can be fitted to a vertical or inclined manometer. The photo electric sensor
is connected to a PCB by an optical fibre.
When energised the PCB generates an infra-red ray which travels along the optic
fibre and throught the manometers liquid column.
The PCB senses when the liquid column breaks the infra-red ray and operates the
switch either making or breaking the contact depending on how it is set.
The ECM can operate on rising or falling pressure by changing the position of the
"inverter switch" on the PCB.
Diagrams 1 and 2 show the operation principle. The switch operates when the
pressure rises and the manometer liquid breaks the infra-red ray at 100 mm H O
2
also lighting the LED.
When the inverter microswitch is operated (diagram 2) the switch operates when
the pressure falls and the infra-red ray is re-established at 100 mm H O.
2
The changeover relay enables the power to be switched on or off with a delay of
up to 45 seconds. Multiple units can be fitted to one manometer column to perform
different functions.