Hach 8398 Series User Manual page 12

1. From the USER TABLE option select P2>INSERT POINT.
2. Enter the conductivity (X) as 250.0 and push enter.
3. Enter the concentration% (Y) as 15.0 and push enter.
4. Select SAVE CHANGES? and push enter.
The table will now be defined as:
P1
P2
P3
Additional points can be inserted up to a maximum of P10.
Note: The conductivity value taken into account is temperature compensated according to the temperature
compensation option configured.
Temperature tables
The process is the same as described for the concentration tables, but the X value refers to
temperature and the Y value is a factor used to multiply against the non-compensated conductivity
value to obtain a temperature compensated conductivity value.
For example, if the temperature table was configured as follows:
P1
P2
P3
This can be displayed graphically as:
This shows that a temperature of 10° corresponds to a factor of 1.05. Therefore, a non-compensated
conductivity value of 10 mS/cm at 10° will give a temperature compensated value of 10.5 mS/cm (i.e.
10 mS/cm multiplied by a factor of 1.05).
Calibrate the sensor
About sensor calibration
The sensor characteristics slowly shift over time and cause the sensor to lose accuracy. The sensor
must be calibrated regularly to maintain accuracy. The calibration frequency varies with the
application and is best determined by experience.
12 English
Conductivity
0
250
750
Temperature
0
20
40
Concentration%
0
15
30
Value
1
1.1
1.2