KROHNE ACM 500 EN - Manual (Page 11)

02/2013 ACM 500 11
Directions for setting the temperature compensation:
•
The actual conductivity measured is indicated in the setting menu. This allows easy laboratory
determination of the temperature coefficient (TC) of a liquid:
-
Dip the device measuring head in the sample liquid (making sure there are no gas
bubbles in the channel bore).
- Heat the sample to exactly 25.0°C, if possible.
- Note down the indicated conductivity (ensure adequate modulation, adjust measuring
range if necessary).
- Heat the liquid to a minimum of 60°C.
- Set the TC in the setting menu to indicate the same conductivity as at 25°C. Bear in mind
that a higher TC value will give a lower conductivity indication.
•
Do not use the TC setting to adjust a measured value. The device is precisely calibrated and
requires no further adjustment. Should you establish variations in the laboratory, please check
whether there are any gas bubbles in the channel bore. If so, dip the device at an incline or
move it quickly in the liquid.
•
If there is no movement of the liquid, there may be slight warming in the channel bore by way
of the device which can lead to a slightly falsified indication. Move the device slightly in the
sample liquid if you wish to obtain very accurate reference measurements.
3.5 Measuring range setting, temperature 9
This is used for setting the current output of the measured temperature, based on 4...20 mA. This
setting is provided only once and cannot be changed externally. In as-delivered condition, the
range selected is 0...150°C. The current output follows under- and overranging of the selected
measuring range up to 10%, i.e. from 2.4 mA to 21.6 mA within the limits of
–20°C...150°C.
The selected setting has no effect on temperature indication.
4..20 m°C
Setting meas. range temperature
for 4...20 mA
90
.............
4.....20 m°C
Setting meas. range temperature
for 4...20 mA (with Jog Shuttle)
91
.............
^
v
Adjustable measuring ranges temperature:
No. Range
Resolution
1 0...150 °C 0.001 °C
2 -20...130 °C 0.001 °C
3 0...100 °C 0.001 °C
4 -20...80 °C 0.001 °C
5 0...50 °C 0.001 °C
6 -10...40 °C 0.001 °C
7 -20...150 °C 0.001 °C