Endress+Hauser Smartec S CLD134 - Concentration Measurement Setup

Smartec S CLD134 Commissioning
Endress+Hauser 47
6.4.8 Concentration measurement
The transmitter can convert conductivity values to concentration values. For this, set the operating
mode to Concentration measurement (see field A1).
You must enter the basic data to which the concentration calculation should refer. For the most
common substances, the required data is already saved in your device. You can select one of these
substances in field K1.
If you want to specify the concentration of a sample, which is not saved in the device, you require
the conductivity characteristics of the medium. To get the characteristics, you can either refer to the
data sheets of the medium or determine the characteristics yourself.
1. To do so, create samples of the medium with the concentrations occurring in your process.
2. Measure the uncompensated conductivity of these samples at temperatures which likewise
occur in your process. To get the uncompensated conductivity, press the PLUS key several
times in measuring mode (see chapter "Key functions") or deactivate the temperature
compensation (Setup 2, field B 2).
– For variable process temperature:
If the variable process temperature should be taken into account for concentration
measurement, you must measure the conductivity of each created sample at two different
temperatures at least (ideally at the lowest and highest process temperature). The
temperature values for the various samples must be identical. However, the difference
between the temperatures must be at least 0.5 °C (0.9 °F).
At least two differently concentrated samples measured at two different temperatures are
required because the transmitter needs a minimum of four references.
– For constant process temperature:
Measure the differently concentrated samples at this constant process temperature.
A minimum of two samples is necessary.
Finally, you should have measuring data which are similar to those shown in the following figures:
T5
Enter temperature
value
0.0 °C
-10.0 ... 150.0 °C
The temperature values must have a
minimum distance of 1 K.
Factory setting for temperature value of value
pairs in table:
0.0 °C; 10.0 °C; 20.0 °C; 30.0 °C ...
T6
Enter temperature
coefficient
α
2.10 %/K
0.00 ... 20.00 %/K
T8
Enter whether or not
the table status is ok
yes
no
If “yes”, return to T.
If “no”, return to T3.
Coding Field Selection or range
(factory settings bold)
Display Info
T5
°C
Temp.val.
0.0
T6
%/K
alpha val
2.10
T8
Status ok
yes