Ecolab LMI03 - Page 108

Conductivity measurement and control device
1
2
3
4
5
Fig. 2: LMI03 control loop
1
Conductivity measurement and control device LMI03
2
Metering pump
3
Detergent tank
4
Measuring point
5
Measuring cell
The LMI03
1
is a measurement and control device that, together with a metering pump
2
and detergent tank
3
, forms a closed control loop. It measures the conductivity of
cleaning solutions using an inductive measuring cell
5
.
The LMI03 controller compares the measured conductivity value (actual value) with a
preset value (nominal value). If the actual value is less than the nominal value set for
conductivity
, a metering pump starts up in order to increase the concentration of the
solution.
Once the concentration level approaches the preset value, the system switches to ‘pulse-
pause mode’ until the preset concentration level is ultimately reached. This reliably
prevents the required concentration from being exceeded.
The control process repeats as soon as the actual value drops below the nominal value.
Temperature compensation
The conductivity changes depending on the temperature of the solution to be determined.
A temperature sensor installed in the measuring cell compensates for the influence of
temperature on the measurement result. In the unit, the temperature compensation factor
can be set to ‘0 – 7’ pH or ‘7 – 14’ pH.
Recommended setting:
n For alkaline cleaning products:
‘7 – 14’ pH
n For acidic cleaning products:
‘0 – 7’ pH
Function description
24MAN049432 Rev. 03-03.2024