Liquisys M CLM223/253

4

Endress+Hauser

Dependability

Reliability

Sensor live check (process check system, PCS (Plus package))

The process check system (PCS) checks the measuring signal for stagnation. An alarm is triggered if

the measuring signal does not change over a specific period (several measured values).

The main causes of stagnating measured values are:

• Contaminated sensor, or sensor outside of medium

• Sensor defective

• Process error (e.g. through control system)

Current output configuration (Plus package)

In order to display wide measuring ranges while still achieving a high resolution in specific ranges,

the current output can be configured as required via a table. This permits bilinear and quasi-

logarithmic curves etc.

Second current output

The second current output can be flexibly configured to output the temperature, the main measured

value (conductivity, resistance, concentration) or the controller actuating variable.

Current input

The transmitter current input permits two different applications:

• Flow monitoring with controller switch-off if flow falls below lower flow level in the main flow

• Feedforward control to the controller

The two functions can also be combined.

Integrity

Temperature compensation

The temperature compensation options are: linear, NaCl curve according to IEC 746, ultrapure water

NaCl (neutral compensation) or ultrapure water HCl (acid compensation, also for ammonia).

The reference temperature is user-definable, the standard value is 25 °C (77 °F).

Polarization detection (Plus package)

Polarization effects in the boundary layer between the sensor and the medium limit the measuring

range of conductive conductivity sensors.

The transmitter can detect polarization effects using a smart signal evaluation process.

Adaptive calibration for determining the installation factor (inductive sensor, Plus package)

The measured value changes if inductive sensors must be installed in narrow pipes at a short

distance from the pipe wall. The built-in adaptive calibration using the installation factor allows you

to compensate for this once the sensor is installed.

Safety

Process safety

Different alarms are required depending on the application and operator. The transmitter therefore

permits the independent configuration of the fault-signaling contact and the error current for every

individual error. Unnecessary or undesired alarms can be suppressed in this way. Up to four contacts

can be used as limit contacts (also for temperature), as a P(ID) controller and for cleaning functions.

The direct manual operation of the contacts (bypassing the menu) enables quick access to limit

value, control or cleaning contacts. Any deviations can be quickly corrected in this way.

Ultrapure water monitoring according to USP (United States Pharmacopoeia) and EP (European

Pharmacopoeia) (Plus package)

Ultrapure water monitoring according to USP <645> or EP means that the uncompensated

conductivity and the temperature are measured and the results are compared against a table. The

transmitter (conductive with additional contacts) has the following functions:

• Monitoring of "Water for Injection" (WFI) according to USP and EP

• Monitoring of "Highly Purified Water" (HPW) according to EP

• Monitoring of "Purified Water" (PW) according to EP