Change Assignment Of The Conductivity Current Output Signal (Zero Point Suppression And Measuring Range Spread); In The Case Of Conductivity Measurement - Ecolab LMIT 08 Notice Technique

8.4.3.5 Change assignment of the conductivity current output signal
(zero point suppression and measuring range spread)
The LMIT 08
final value of the measuring range is assigned to the current output signal 0(4)... 20 mA.
In addition, it is possible to effect an optimum range spread and zero point suppression
depending on the measuring task. This may be necessary for example, if small changes in
measuring signal with a large resolution, have to be detected.
Besides the choice of current output range 0...20 mA or 4..20 mA, the start of the measuring
spread (ZERO POINT) and the end of the measuring spread (SPAN) can be freely selected
within the specified limits.
NOTE
If the PR01 controller is used, zero point suppression and range spread cannot be used.
Fig. 8.23

8.4.3.5.1 In the case of conductivity measurement

Fig. 8.24
Example of zero point suppression and measuring range spread:
•
Required conductivity measuring range: 1,6 mS/cm...3 mS/cm,
•
Zero point suppression:
•
Range spread SPAN:
417101109_LMIT08.doc
transmitter was designed in such a way that in the standard setting the starting and
The configuration currently set is displayed without CURSOR mark
and .
Setting limits:
- zero_point:
0..80 % of the measuring range
- SPAN:
20..150 % of the measuring range
corresp. to 0...20 mA
0 mA = 1,6 mS/cm,
corresp. to 80 % of measuring range 0 - 2 mS/cm
20 mA = 3,0 mS/cm,
corresp. to 150 % of measuring range 0 - 2 mS/cm
- 69 - Rev. 3-01.10