Ecolab LMI03 - 4 Function Description

4 Function description
The LMI03 includes all functions necessary for measuring and controlling conductivity
.
By connecting a corresponding metering pump, the LMI03 becomes an autonomously
operating metering system.
The ‘Setup’ menu on the LMI03
enables users to choose between two operating modes:
n ‘AS mode’ for make-up mode (factory setting)
n ‘CIP mode
’ for phase separation
Measurement principle
The LMI03 operates according to the inductive measurement principle without electrodes.
Fluids with dissolved substances have an electrical conductivity depending on their
dissociation level. The specific conductivity (χ) is expressed in mS/cm and is characteristic
of the individual substance. The conductivity measurement can be used to determine the
concentration of a solution.
A
1
2
3
4
5
6
7
7
Fig. 1: Measuring principle
A
LMI03
1
Oscillator
2
Transmitter coil
3
Current flow in the fluid
4
Receiver coil
5
Temperature sensor
6
Measurement amplifier
7
Flow
The excitation current in the transmitter coil
2
generates an alternating magnetic field in
its core.
This induces an electrical voltage in the fluid that is flowing through
7
. A current
flows across the ions present in the liquid
3
, which increases at higher levels of ion
concentration.
The electric current in the flowing fluid generates an alternating magnetic field in the
receiver core. The resulting induction current in the receiver coil
4
is transmitted to the
measuring amplifier as a measuring current for further processing
6
.
NOTICE!
The following sections describe the functions available in AS mode.
Function description
23 MAN049432 Rev. 03-03.2024