Process calibrator or simulator: selecting the right calibration device for pressure, Pt100, thermocouple and 4–20 mA

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Anyone who wants to check transmitters, sensors, pressure transmitters, temperature probes or PLC inputs quickly faces the question: Is a simple simulator sufficient, or is a full process calibrator required? The answer depends on which signals need to be tested, whether only one signal is simulated or whether measurements, sourcing, documentation and reference modules are also required.

A process calibrator is a versatile test instrument for industrial measurement and control technology. Depending on the version, it can measure and source electrical signals, simulate temperature probes, integrate pressure modules, test 4–20 mA current loops and document measured values. A simulator, on the other hand, is usually specialized in specific signal types, for example Pt100, thermocouples, mV, V or resistance.

This article explains the difference between a process calibrator and a simulator, shows typical applications and helps you select the right calibration device for pressure, temperature, electrical signals, PLC inputs and transmitters.

You can find suitable devices in our categories
process calibrators,
simulators
and
pressure calibration technology.
For extensive calibration tasks, DPI620 GENII and DPI880 are particularly relevant. For simulating Pt100, RTD, thermocouple, mV and V, the ICS 02S simulator can be a suitable solution.

Process calibrator or simulator: what is the key question?

The most important question is not initially “Which device is the best?”, but: Which task needs to be solved? If you only want to check whether a temperature controller responds correctly to a simulated Pt100 value, you usually do not need a large multifunction device. However, if pressure transmitters, temperature transmitters, 4–20 mA current loops and PLC inputs need to be checked in the field, a much more versatile calibration device is required.

In practice, there are three typical situations. First: a signal only needs to be simulated, for example a Pt100 resistance or a thermocouple signal. Second: a signal needs to be measured or actively sourced, for example 4–20 mA. Third: a complete measuring chain needs to be checked, meaning sensor, transmitter, output signal, display and PLC scaling together.

The more signal types, documentation requirements and measurement tasks are involved, the more likely a process calibrator is the right choice. The clearer and more limited the task is, the more likely a simulator will be sufficient.

What is the difference between a calibrator and a simulator?

A simulator reproduces a sensor signal. During testing, it replaces the sensor and sends a defined signal to a controller, display, transmitter or PLC input. Typical examples are the simulation of Pt100, RTD, thermocouple, mV or V. The user checks whether the connected device correctly detects the simulated value.

A process calibrator can do more. Depending on the device, it measures and sources electrical signals, simulates sensors, checks current loops, supplies transmitters, uses pressure modules and sometimes also supports documentation functions. This makes it suitable not only for simple signal testing, but also for systematic calibration and troubleshooting of measuring chains.

Device type	Typical function	Suitable for
Simulator	Outputs defined sensor signals.	Testing controllers, displays, transmitters and PLC inputs.
Loop calibrator	Measures, sources or simulates mA signals.	4–20 mA current loops, transmitters and PLC inputs.
Multifunction calibrator	Measures and sources various electrical and sensor signals.	Service, maintenance, laboratory and commissioning.
Pressure calibrator	Checks pressure measuring devices, often with pressure modules or pressure generation.	Pressure sensors, pressure gauges, pressure transmitters and pressure switches.

Understanding measuring, sourcing and simulating correctly

When selecting a calibration device, it is important to clearly distinguish between measuring, sourcing and simulating. When measuring, the device records an existing signal. When sourcing, the device actively generates a signal, for example 12 mA or 100 mV. When simulating, the device behaves like a sensor, such as a Pt100 or thermocouple.

This distinction is crucial in troubleshooting. If a PLC input needs to be checked, the calibrator sources or simulates a signal. If a transmitter output needs to be checked, the calibrator measures the existing output signal. If a temperature transmitter needs to be checked without a real probe, the device simulates a Pt100 or a thermocouple.

Many misinterpretations occur because the wrong operating mode is selected. A passive input requires an active signal. A passive 2-wire transmitter requires loop supply. A thermocouple input requires the correct thermocouple signal and suitable cold junction compensation.

When is a simple simulator sufficient?

A simple simulator is sufficient when the test task is clearly limited. This is the case, for example, when a controller, display or transmitter is to be checked regularly with defined Pt100, RTD, thermocouple, mV or V signals.

The advantage of a simulator is its simple operation. The user selects the sensor type or signal value and checks whether the connected device responds correctly. For workshop use, control cabinet construction, commissioning and quick functional checks, this is often completely sufficient.

A simulator is particularly useful when no pressure needs to be measured, no extensive documentation is required and the task does not involve several signal types at the same time.

Typical task	Why a simulator is sufficient	Example
Checking a Pt100 input	A defined resistance value is simulated.	Controller displays the corresponding temperature for the simulated value.
Checking a thermocouple input	Thermoelectric voltage is reproduced.	Display or transmitter is tested without a real probe.
Checking an mV or V input	A defined voltage signal is sufficient.	Checking PLC or transmitter input.
Workshop test	Recurring standard values are required.	Functional check before delivery or installation.

When is a process calibrator useful?

A process calibrator is useful when several signal types need to be checked or when the measurement task goes beyond simple simulation. This is often the case in maintenance, service, plant shutdowns, commissioning or calibration laboratories.

A multifunction calibrator can process mA, mV, V, ohms, frequency, pulses, RTD and thermocouples, for example. With suitable pressure modules, pressure can also be measured. This allows various measuring points to be checked with one device.

The process calibrator is particularly strong when measuring chains need to be evaluated. It not only helps answer whether an input responds, but also whether sensor, transmitter, signal, display and output work together correctly.

Calibrating pressure: when pressure modules or pressure calibrators are required

A simple electrical simulator is not sufficient for pressure measuring devices. Anyone who wants to check pressure sensors, pressure gauges, pressure transmitters or pressure switches needs a pressure reference and, depending on the task, pressure generation. This can be a separate pressure calibrator, a pressure module with hand pump or a pressure controller.

With a pressure transmitter, a defined pressure is typically applied while the output signal is checked at the same time. A multifunction calibrator with pressure module can record the reference pressure and measure the electrical output signal such as 4–20 mA. This allows the complete measuring chain to be evaluated.

No pressure module is required for purely electrical tests. However, as soon as the physical pressure value is part of the calibration, a suitable pressure reference must be used.

Checking temperature: simulating Pt100, RTD and thermocouples

For temperature measuring points, there are two typical tasks. Either a real temperature probe needs to be checked, or the input of a measuring device needs to be tested with a simulated sensor signal. For the second task, a simulator or multifunction calibrator is suitable.

Pt100 and RTD signals are simulated as resistance. Thermocouples are simulated via a small thermoelectric voltage. The correct sensor type must always be selected. A Type K input must not be checked with Type J values if the display is to be evaluated correctly.

For complete temperature calibration of a real probe, additional temperature sources such as dry block calibrators, liquid baths or reference thermometers are required. For pure input simulation, however, a suitable simulator is sufficient.

Electrical signals: mA, mV, V, ohms, frequency and pulses

Many process signals are electrical. These include 4–20 mA, 0–10 V, mV signals, resistance values, frequencies and pulses. These signals are used in automation for measured values, limit values, speeds, counters, flow pulses or control variables.

A simple simulator often covers only part of these signals. A multifunction calibrator is more flexible and can measure and source several signal types. This saves device changes and makes troubleshooting faster.

For 4–20 mA current loops, it is also important whether the device only measures mA, actively sources mA or can simulate a passive transmitter. In addition, 24 V loop supply may be required.

Checking PLC inputs and transmitters

A typical application is checking a PLC input. The calibrator sends a defined signal to the input, for example 4, 12 and 20 mA or a simulated Pt100 value. It is then checked whether the PLC displays the corresponding process value.

Transmitters can also be checked systematically in this way. With a temperature transmitter, for example, a Pt100 or thermocouple signal is simulated and the 4–20 mA output is measured. This shows whether input, conversion and output signal work correctly.

This approach separates fault sources clearly. If the PLC input responds correctly with a simulated signal, the fault is more likely to be in the field device or wiring. If the input responds incorrectly, the scaling or input card must be checked.

Field use or laboratory: different requirements

In the field, robustness, battery life, simple operation, clear display and quick connection options are important. Devices must work reliably even in harsh environments. Measuring points are often checked under time pressure, for example during shutdowns or faults.

In the laboratory or workshop, however, accuracy, repeatability, documentation and flexible signal coverage are more important. Recurring tests are often carried out there, and measurement results must be documented in a traceable way.

The choice of the right device therefore also depends on the place of use. A compact simulator can be ideal in the workshop, while a multifunction calibrator offers significantly more flexibility in the field.

DPI620 GENII: multifunction calibrator for demanding tasks

The DPI620 GENII is particularly interesting when a versatile process calibrator for electrical signals, frequency, temperature and pressure is required. It is suitable for demanding service, maintenance and calibration tasks where several signal types and measurement functions need to be combined in one device.

In combination with suitable pressure modules, the DPI620 GENII can also be used for pressure calibrations. This makes it a flexible solution for users who do not only want to simulate 4–20 mA or temperature, but need to check different measuring points in the field.

Typical applications include checking pressure transmitters, temperature transmitters, electrical process signals, frequency inputs, current loops and complete measuring chains.

DPI880: multifunction calibrator for electrical signals, RTD/TC and pressure modules

The DPI880 is a multifunction calibrator for users who want to check various electrical and process-related signals. These include mA, mV, V, ohms, frequency, pulses as well as RTD and thermocouple signals.

With suitable pressure modules, the DPI880 can also support pressure measurement tasks. This makes it suitable for maintenance, workshop, service and commissioning when one device should cover as many typical signal types as possible.

The DPI880 is particularly useful when the user needs a compact, versatile device for different measuring and simulation tasks, but does not want to use a separate test instrument for each signal type.

ICS 02S: simulator for Pt100, RTD, thermocouple, mV and V

The ICS 02S is a simulator for typical temperature and voltage signals. It is particularly suitable for users who want to simulate Pt100, RTD, thermocouples, mV or V without needing a complete multifunction calibrator.

The device is especially practical for checking temperature controllers, displays, transmitters and PLC inputs. The user can define sensor values and check whether the connected device detects the corresponding temperature or signal value.

If the task mainly consists of simulating temperature probes or voltage signals, a specialized simulator such as the ICS 02S is often the more economical and simpler solution.

Product comparison: which device is suitable?

The selection should always be based on the specific test task. A simulator is ideal for clear, recurring input tests. A multifunction calibrator is the better choice when many signal types, measurement functions or pressure modules are required.

Device / category	Strengths	Typical application
Process calibrators	Measure, source and simulate several signal types.	Service, maintenance, laboratory and commissioning.
Simulators	Specialized simulation of sensor and standard signals.	Testing controllers, displays, PLC inputs and transmitters.
DPI620 GENII	Electrical signals, frequency, temperature and pressure with suitable modules.	Demanding multifunction calibration in the field.
DPI880	mA, mV, V, ohms, frequency, pulses, RTD/TC and pressure modules.	Universal calibration tasks in service and workshop.
ICS 02S	Simulation of Pt100, RTD, thermocouple, mV and V.	Simple and fast input simulation.
Pressure calibration technology	Pressure references, pressure modules, pumps and pressure calibrators.	Pressure sensors, pressure gauges, pressure transmitters and pressure switches.

Practical examples from maintenance, laboratory and commissioning

Example 1: Checking the Pt100 input of a controller

A temperature controller displays implausible values. A simulator is used to specify a defined Pt100 value. If the controller responds correctly, the fault is more likely to be in the probe or the cable. If it responds incorrectly, the input or parameterization must be checked.

Example 2: Fully calibrating a pressure transmitter

A pressure transmitter is not only to be checked electrically, but fully calibrated. A defined pressure is required for this, and the 4–20 mA output signal is measured at the same time. In this case, a process calibrator with pressure module or a pressure calibrator is required.

Example 3: Testing a PLC input with 4–20 mA

During commissioning, it needs to be checked whether an analog PLC input is correctly scaled. The calibrator outputs 4, 12 and 20 mA. The PLC must display the corresponding process values.

Example 4: Checking a thermocouple input without a real probe

A furnace controller is to be checked before installation. A simulator outputs a Type K or Type J signal. This makes it possible to check whether the controller detects the correct temperature value and whether the input is configured correctly.

Example 5: Service device required for different measuring points

A service technician regularly needs to check pressure, temperature, 4–20 mA, voltage, resistance and frequency. In this case, a multifunction calibrator is more useful than several individual simulators.

Checklist: selecting the right calibration device

This checklist helps you choose between simulator, loop calibrator, multifunction calibrator and pressure calibrator.

Check question	Why important?	Recommendation
Should only inputs be simulated?	Then a multifunction calibrator is often not necessary.	Check a simulator such as ICS 02S.
Are 4–20 mA current loops being checked?	Measuring, sourcing, simulating and loop supply may be required.	Select a loop calibrator or multifunction calibrator.
Do several signal types need to be checked?	One device saves time and reduces sources of error.	Check DPI620 GENII or DPI880.
Does pressure need to be calibrated?	Pressure requires a reference and possibly pressure generation.	Select pressure module, pressure calibrator or pressure calibration technology.
Are Pt100, RTD or thermocouples required?	Temperature signals must be simulated according to type.	Select an RTD/TC-capable device.
Is documentation required?	Data is important for audits and quality management.	Check calibrator with documentation function.
Will the device be used in the field?	Robustness, battery and operation are decisive.	Select a field-suitable device.
Will it mainly be used in the laboratory?	Accuracy and repeatability are the priority.	Consider suitable reference and calibration uncertainty.

Conclusion: simulator for simple signals, process calibrator for complete measuring chains

Whether a process calibrator or a simulator is required depends directly on the test task. A simulator is ideal when defined Pt100, RTD, thermocouple, mV or V signals need to be output. It is simple, economical and completely sufficient for many input tests.

A process calibrator is the better choice when several signal types, current loops, pressure modules, measurement functions or complete measuring chains need to be checked. Especially in service, maintenance and commissioning, a multifunction calibrator offers significantly more flexibility.

For extensive calibration tasks, DPI620 GENII and DPI880 are particularly interesting. For targeted simulation of Pt100, RTD, thermocouple, mV and V, the ICS 02S simulator can be a suitable solution. You can find an overview of suitable devices in the categories
process calibrators,
simulators
and
pressure calibration technology.

FAQ: frequently asked questions about process calibrators and simulators

What is the difference between a process calibrator and a simulator?

A simulator outputs defined sensor signals or standard signals. Depending on the version, a process calibrator can additionally measure, source and simulate signals, use pressure modules, check current loops and calibrate measuring chains.

When is a simulator sufficient?

A simulator is sufficient when the main task is to check inputs of controllers, displays, PLCs or transmitters with defined Pt100, RTD, thermocouple, mV or V signals.

When do I need a process calibrator?

A process calibrator is useful when several signal types need to be checked, mA signals need to be measured and sourced, pressure modules are required or complete measuring chains need to be calibrated.

How can a Pt100 be simulated?

A Pt100 is simulated using a corresponding resistance value. A simulator or multifunction calibrator provides this value so that controllers, displays or transmitters can be checked.

How do you simulate a thermocouple?

A thermocouple is simulated using a small thermoelectric voltage. The correct thermocouple type must be selected, for example Type J, Type K or Type T.

Can a simulator calibrate pressure?

No, pressure calibration requires a pressure reference and, depending on the task, pressure generation. Pressure modules, pressure calibrators, hand pumps or pressure controllers are required for this.

How do you check a PLC input?

The calibrator or simulator sends a defined signal to the PLC input. It is then checked whether the PLC displays the correct process value.

What is the DPI620 GENII suitable for?

The DPI620 GENII is suitable for demanding process calibrations with electrical signals, frequency, temperature and pressure in combination with suitable modules.

What is the DPI880 suitable for?

The DPI880 is suitable for multifunction calibrations with mA, mV, V, ohms, frequency, pulses, RTD/TC and pressure modules.

What is the ICS 02S suitable for?

The ICS 02S is suitable as a simulator for Pt100, RTD, thermocouple, mV and V. It is particularly practical for checking temperature controllers, displays, transmitters and PLC inputs.

Which products are suitable for process calibration and simulation?

For extensive process calibration, DPI620 GENII and DPI880 are suitable. For targeted simulation of Pt100, RTD, thermocouple, mV and V, the ICS 02S is relevant. Suitable categories are
process calibrators,
simulators
and
pressure calibration technology.