Product description
Waterpilot FMX21
12
Hauser
3
Product description
3.1
Function
The ceramic measuring cell is a dry measuring cell i.e. the pressure acts directly on the
robust, ceramic process isolating diaphragm of the Waterpilot FMX21. Changes in air
pressure are guided via a pressure compensation tube through the extension cable to the
rear of the ceramic process isolating diaphragm and are compensated for. A pressure-
dependent change in capacitance, caused by the movement of the process isolating
diaphragm, is measured at the electrodes of the ceramic carrier. The electronics unit then
converts this to a signal that is proportional to the pressure and linear to the level.
h
2
1
p
atm
p
hydr.
p = p
+ p
atm
hydr.
p
atm
p
atm
h ~ p
r
•
g
h =
p
Rel.: p
= (p
+ p
) - p
sens
atm
hydr.
atm
p = p
+ p
atm
hydr.
Abs.: p
= (p
+ p
)
sens
atm
hydr.
A0019140
1
Ceramic measuring cell
2
Pressure compensation tube
h
Height level
p
Total pressure = atmospheric pr hydrostatic pressure
ρ
Density of the medium
g
Acceleration due to gravity
P
hydr.
Hydrostatic pressure
P
atm
Atmospheric pressure
P
sens
Pressure displayed on the sensor
Summary of Contents for Waterpilot FMX21
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