Testing Conductivity Meters and Simulating Sensor Signals

Reliable conductivity measurements require both the sensors and the connected measuring instruments to function correctly. If implausible measurement values or deviations occur, it is necessary to determine whether the cause lies in the sensor, temperature compensation or signal processing of the measuring instrument.

The HORIBA X-52 Digital Simulator is a testing instrument designed to simulate defined electrical substitute signals for conductivity and temperature measurement (COND/TEMP). It enables functional testing of compatible conductivity meters without requiring an actual water sample.

The simulator provides theoretical electrical input signals that replicate the behaviour of corresponding sensors. This makes it possible to check how a connected measuring instrument responds to predefined input signals.

For conductivity measurement, the HORIBA X-52 generates an electrical substitute resistance. For temperature measurement, a temperature-dependent substitute resistance signal is provided, corresponding to the behaviour of a thermistor.

One of the main applications is the regular functional testing of conductivity meters. The HORIBA X-52 particularly supports the verification of linearity and temperature compensation functions.

Unlike a conductivity meter, the simulator does not directly measure water parameters in a sample. Instead, it provides defined electrical input signals that can be used to check the signal processing of the connected measuring instrument.

This makes the HORIBA X-52 particularly suitable for servicing, technical troubleshooting, regular instrument inspections and quality assurance in electrochemical measurement technology.

Simulated Measurement Parameters of the HORIBA X-52

The digital simulator provides electrical substitute resistances for testing compatible conductivity meters. Two essential measurement functions are taken into account.

• Electrical Conductivity (COND): Simulation of a defined electrical substitute resistance to verify conductivity measurement and the associated signal processing.
• Temperature (TEMP): Simulation of a temperature-dependent resistance signal corresponding to the electrical behaviour of a thermistor. This enables testing of the temperature measurement function and supports verification of temperature compensation.

The simulated signals are used to verify the electrical inputs of measuring instruments and their associated evaluation functions. They do not replace measurements of actual water samples or comprehensive testing of the connected conductivity sensor.

Functions and Features

Simulation of Defined Conductivity Signals

In conductive conductivity measurement, the electrical conductivity of a liquid is determined based on its electrical characteristics. Evaluation takes into account the properties of the sensor used.

The HORIBA X-52 provides defined electrical substitute resistances for testing compatible measuring instruments. These serve as theoretical input signals for the conductivity measurement function.

The connected measuring instrument can therefore be tested using predefined electrical signals. By evaluating the displayed conductivity values, it is possible to determine whether signal processing operates within the specified test criteria.

Simulation of Temperature-Dependent Resistance

The electrical conductivity of a water sample depends on temperature. For this reason, many conductivity meters also measure temperature and take it into account when calculating temperature-compensated measurement values.

For this purpose, the HORIBA X-52 provides an electrical substitute resistance corresponding to the signal of a thermistor.

This makes it possible to verify whether the connected measuring instrument processes a corresponding temperature signal as expected.

Verification of Linearity

Linearity describes how consistently a measuring instrument responds to different input signals within its specified measuring range.

With the HORIBA X-52, defined substitute resistances can be applied and compared with the displayed measurement values.

This test supports the identification of possible deviations in the signal processing of the conductivity meter.

Checking Temperature Compensation

Since the conductivity of a liquid changes with temperature, temperature compensation is important for the comparability of many conductivity measurements.

The HORIBA X-52 supports verification of this function by simulating suitable electrical input signals for conductivity and temperature.

This makes it possible to check whether the measuring instrument processes the simulated signals according to its specified settings and calculation functions.

Support for Troubleshooting

If implausible or fluctuating values are displayed during conductivity measurement, several possible causes must be considered.

These may include contaminated or damaged conductivity sensors, incorrect temperature measurement, connection problems or faults in the measuring instrument electronics.

By applying a defined substitute signal, it is possible to check whether the measuring instrument processes this signal as expected.

This helps systematically narrow down possible sources of error and carry out further testing or maintenance steps more effectively.

Testing Without an Actual Water Sample

No conductivity standard solution or water sample is required for electrical functional testing of the measuring instrument. Instead, defined electrical substitute signals are used.

This enables targeted testing of the measuring instrument electronics, independently of influences caused by the characteristics of an actual water sample.

However, testing with a simulator does not replace the necessary calibration and inspection of the actual sensor using suitable reference solutions.

For Regular Functional Testing

The digital simulator can be used for recurring inspections to check the behaviour of compatible conductivity meters using defined input signals.

The evaluation of test results is based on the technical specifications of the respective measuring instrument and the applicable testing procedures.

Typical Applications

The HORIBA X-52 is suitable for various testing and service tasks in conductivity and temperature measurement technology.

• Laboratory Analysis: Functional testing of compatible conductivity meters in laboratory applications.
• Service and Maintenance: Verification of electrical signal processing during regular instrument inspections.
• Technical Troubleshooting: Identification of possible causes of implausible or deviating conductivity readings.
• Quality Assurance: Support for documented functional testing of conductivity meters.
• Linearity Testing: Comparison of predefined electrical substitute resistances with displayed measurement values.
• Temperature Compensation: Verification of the temperature measurement function and temperature-dependent calculations.
• Technical Customer Service: Systematic testing of compatible measuring instruments during maintenance and service work.
• Research and Development: Support for functional testing of suitable conductivity measurement systems.

Advantages of Digital Sensor Simulation

• Simulation of electrical substitute signals for conductivity and temperature.
• Testing of compatible conductivity meters without an actual water sample.
• Support for verifying measuring instrument linearity.
• Verification of temperature measurement and temperature compensation functions.
• Systematic identification of possible error sources in signal processing.
• Suitable for regular functional testing and technical service work.
• Support for traceable documentation of test results.
• Conductivity and temperature simulation combined in one testing instrument.

Technical Information and Downloads

The HORIBA X-52 Digital Simulator is designed to simulate theoretical electrical input signals for compatible conductivity meters.

Electrical substitute resistances are provided for conductivity measurement, while corresponding thermistor-equivalent resistance signals are provided for temperature measurement.

Information on the available simulation ranges, connection options, operating functions and testing procedures can be found in the instruction manual in the download section.

Before use, check the compatibility of the simulator with the respective measuring instrument, as well as the required connections and testing specifications.

Note on Use: The HORIBA X-52 is a simulator designed to verify electrical measuring instrument inputs and associated evaluation functions. It does not replace the calibration and maintenance of actual conductivity sensors or any comprehensive metrological verification of the measurement system that may be required.

Note on Scope of Delivery: From November 2026, HORIBA products will be supplied without batteries. Existing stock may still include batteries. Batteries are no longer included with newly manufactured products and must be purchased separately if required.