C) Logarithmic current output signal characteristic
Sensor Range 20 mA input Input range of knee value
Conductivity
CLS 50 200 mS/cm – 1000 mS/cm
20.0 µS/cm – 200.0 mS/cm
CLS 52 2.00 mS/cm – 1000 mS/cm
200 µS/cm – 200.0 mS/cm
k=0.01
0.200 µS/cm – 200.0 µS/cm 20.0 nS/cm – 20.00 µS/cm
k=0.1
2.00 µS/cm – 2000 µS/cm 0.200 µS/cm – 200.0 µS/cm
k=1
20.0 µS/cm – 20.00 mS/cm 2.00 µS/cm – 2000 µS/cm
k=10
200 µS/cm – 200.0 mS/cm 20.0 µS/cm – 20.00 mS/cm
MΩ
k=0.01
200 kΩ cm – 20.00 MΩ cm 20.0 kΩ cm – 2000 kΩ cm
k=0.1
20.0 kΩ cm – 2000 kΩ cm 2.00 kΩ cm – 200.0 kΩ cm
k=1
2.00 kΩ cm – 200.0 kΩ cm 0.200 kΩ cm – 20.00 kΩ cm
The minimum current output spread TD is determined by the switching step in which the knee point is located.
It is 10% of the switching step end value (see Table »linear«).
The measured value for the knee point must be less than (20 mA value – TD).
The 0/4 mA value must always be defined as 0 S/cm.
20
Output current [mA]
Current output meas. range [%]
0 20 40 60 80 100
I = 4 (0) mA + 8 (10) mA log
Values in brackets for
current output 0...20 mA
CD value
20 mA value
100
4
(0)
12
(10)
i_out_lg.cdr
Fig. 7.4
Current output signal
with logarithmic
characteristic
Instrument configuration Mycom CLM 152
44 Endress+Hauser