Technical information

Ultrasonic Level Sensor LUC-M**
Input
DOCT-0805F 01/2010 185414
5
Input
Measured variable The distance D between the sensor membrane and the product surface is measured.
Using the linearisation function, the device uses D to calculate:
• level L in any units
• volume V in any units
• flow Q across measuring weirs or open channels in any units
Measuring range The measuring range is limited by the range of a sensor. The sensor range is, in turn, dependent
on the operating conditions. To estimate the actual range, proceed as follows (see also the
calculation example):
1. Determine which of the influences shown in the following table are appropriate for your process.
2. Add the corresponding attenuation values.
3. From the total attenuation, use the diagram to calculate the range.
Fluid surface Attenuation
calm 0 dB
waves 5 dB ... 10 dB
strong turbulence (e. g. stirrers) 10 dB ... 20 dB
foaming ask Pepperl+Fuchs
Bulk material surface Attenuation
hard, rough (e. g. rubble) 40 dB
soft (e. g. peat, dust-covered clinker) 40 dB ... 60 dB
Dust Attenuation
no dust formation 0 dB
little dust formation 5 dB
heavy dust formation 5 dB ... 20 dB
Filling curtain in detection range Attenuation
none 0 dB
small quantities 5 dB ... 10 dB
large quantities 10 dB ... 40 dB
Temperature difference between sensor and product surface Attenuation
to 20 °C (293 K) 0 dB
to 40 °C (313 K) 5 dB ... 10 dB
to 80 °C (353 K) 10 dB ... 20 dB
LUC-M30
LUC-M40
LUC-M20
LUC-M10
10 20 30 40 50 60 70 80
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Attenuation in dB
Range in m