Instrument Description; Applications; Operating Principle; Measuring Functions - Endress+Hauser Mycom CLM 152 Operating Instructions Manual

Mycom CLM 152
4
3

Instrument description

3.1

Applications

The Mycom CLM 152 measuring transmitter is
specially designed for carrying out measuring
and control tasks in the following applications:
3.2

Operating principle

Inductance principle
In inductive conductivity measurement, a
transmitter coil generates a continuous
alternating magnetic field that induces an
electric voltage in a liquid.
A current flows due to the ions present in the
liquid. The current increases as the ion
concentration rises. The ion concentration
acts as a measure of conductivity. The
current in the liquid generates an alternating
magnetic field in the receiving coil.
The resulting current induced in the receiving
coil is processed in the measuring instrument
and is output as a conductivity value.
The advantage of this set-up is the fault-free
measurement in liquids that have a tendency
to sediment; there is no electrically
conductive connection between the sensor
and the liquid and there is no polarisation
since there are no electrodes.
3.3

Measuring functions

Concentration measurement
In this operating mode, the instrument stores
the data for NaOH, HNO , H
3
The operator can enter and store the
individual data for four other substances
within the permitted ranges, and, if required,
can activate them as a concentration
measuring range. See Chapter 7.1.1
"Measured variable".
Differential measurement
(if equipped with two measuring channels)
Two sensors are used at different points in a
process, e.g. to monitor heat exchangers
(upstream and downstream of the exchanger)
in media separation or mixture control
applications. The difference between the two
measuring results is used to control the
process.
• Foodstuffs industry
• Pharmaceuticals
• Chemical process engineering
• Water treatment
• Drinking water
• Monitoring ultra-pure water
Conductance principle
When ions are subjected to an electrical field,
and depending on their electrolytic excess
carrier, they either become cations and
migrate to a positively charged electrode, or
they become anions and migrate to a
negatively charged electrode. The migration
speed of the ions is directly proportional to
the current strength recorded in the
measuring instrument as a conductivity value.
Polarisation compensation (conductive)
Polarisation effects in the boundary layer
between the electrode and the measuring
solution limit the measuring range of
conductive sensors. The Mycom
CLM 152 measuring transmitter can detect
and compensate for polarisation effects using
an innovative, intelligent signal evaluation
process. This results in a significant
expansion of the useful measuring range of a
sensor (cf. Overview of Conductivity Sensors).
Measuring range switch-over
The instrument can store the following
SO and H PO . settings for four measuring ranges:
2 4 3 4
• Measuring range allocation for current
output (0/4 and 20 mA)
• Setpoint and hysteresis for existing
limit contacts.
• Temperature coefficients
• Type of temperature compensation
Switch-over takes place by internal
configuring the internal trigger thresholds or
alternative external by wiring the binary inputs
(add-on module FCXI required).
Instrument description
Endress+Hauser