VARIOHM Temperature Sensors – Reliable Measurement in the Real World

🧩 Further Reading – Measurement as a System

This article is part of an engineering series exploring how reliable measurement depends on proper system design rather than on a single sensor component.

Before diving deeper into industrial temperature sensing, you may also find the following articles in the series useful:

• VARIOHM Group – When Measurement Is a System, Not a Component
• How to Select Sensors for Harsh Environments: An Engineering Guide for Reliable Measurement in the Real World
• VARIOHM Position Sensors – Engineering Position as a System, Not Just a Signal
• Industrial Pressure Sensors – When Pressure Measurement Becomes a System Engineering Challenge

Together, these articles highlight a key engineering principle:
Reliable measurement begins with system architecture – not just sensor selection.

Temperature Measurement – Far More Than Just a Sensor

Temperature is one of the most critical physical parameters in industrial systems.

From energy systems and medical equipment to industrial machinery and advanced transportation platforms, accurate temperature measurement directly impacts:

• Process control
• System safety
• Equipment reliability
• Energy efficiency

Yet despite its importance, temperature measurement is often treated as a simple task.

Engineers frequently assume that selecting a sensor with the correct measurement range and accuracy specification will automatically guarantee reliable results.

In reality, stable and accurate temperature measurement depends on a wide range of engineering factors.

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Why Temperature Measurements Fail in Real Systems

In many systems, temperature sensors perform perfectly during laboratory testing.

However, once the system operates in real-world conditions, significant measurement deviations may appear.

This occurs because temperature measurement is influenced by several external factors:

• Sensor placement within the system
• Air or fluid flow around the sensor
• Thermal mass of the measured surface
• Rate of temperature change
• Environmental influences
• Electrical noise

In many cases, the problem is not the sensor itself.

The problem is how the sensor is integrated into the system.

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Common Temperature Sensing Technologies

Industrial measurement systems typically rely on several key sensing technologies.

Each technology offers advantages depending on the application.

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NTC Thermistors

NTC thermistors are resistive sensing elements whose resistance changes with temperature.

Key characteristics:

• High sensitivity
• Fast response time
• Excellent detection of small temperature variations

They are widely used in:

• Medical equipment
• Industrial electronics
• Control systems
• Battery monitoring

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RTD Sensors

RTD sensors are typically based on platinum elements such as PT100 or PT1000.

Key characteristics:

• High accuracy
• Excellent long-term stability
• Ideal for industrial process monitoring

RTDs are considered among the most reliable temperature sensing technologies for demanding industrial environments.

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Temperature Probes

Temperature probes integrate the sensing element into a mechanical structure designed for specific installation conditions.

This allows measurement in:

• Liquids
• Metal surfaces
• Industrial processes

The mechanical design of the probe significantly affects response time and measurement accuracy.

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Temperature Switches

In many systems, continuous temperature measurement is not required.

Instead, the system only needs to detect when a certain temperature threshold is reached.

In these cases, temperature switches are used.

When the temperature reaches a predefined point, the switch activates or disconnects an electrical circuit.

These solutions are commonly used for thermal protection and safety systems.

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Common Temperature Measurement Design Mistakes

Even when high-quality sensors are selected, several design mistakes can cause unstable readings.

Typical mistakes include:

• Sensor placement that does not represent the actual system temperature
• Poor thermal contact with the measured surface
• Ignoring thermal response time
• Heat transfer through surrounding mechanical structures
• Effects of thermal radiation

These issues may cause delayed response or inaccurate control behavior within the system.

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Case Study – Temperature Measurement Drift in an Industrial System

The Challenge

An industrial machine required accurate temperature monitoring to protect sensitive components.

Laboratory testing showed stable and accurate readings.

However, once installed in the real system, measured temperatures were consistently lower than expected.

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Root Cause

Engineering analysis revealed several contributing factors:

• The sensor was positioned too far from the heat source
• A large mechanical structure caused thermal delay
• Airflow around the sensor created localized cooling

The issue was not the sensor.

It was how the sensor was integrated into the system.

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The Solution

Several improvements were implemented:

• Relocating the sensor closer to the heat source
• Improving thermal contact with the measured surface
• Selecting a probe design better suited for the application

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Result

After these adjustments:

• Temperature readings became significantly more accurate
• System control stability improved
• Thermal protection became more reliable

The conclusion is clear:

Reliable temperature measurement begins with proper system design.

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VARIOHM Temperature Sensors

VARIOHM develops and manufactures a wide range of temperature sensing solutions designed for demanding industrial applications.

The portfolio includes:

• High-sensitivity NTC thermistors
• Precision RTD sensors for industrial environments
• Customizable temperature probes for mechanical integration
• Temperature switches for thermal protection

These solutions are engineered to deliver stable performance in real operating environments – not just laboratory conditions.

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VARIOHM Temperature Sensors – Available in Israel Through Amironic

Amironic represents VARIOHM sensing solutions in Israel.

Engineers benefit from:

• Assistance in selecting the correct sensing technology
• Matching the sensor to environmental conditions
• Support in measurement system design
• Integration guidance for complex applications

Selecting a temperature sensor is not just a component decision.

It is part of designing a reliable measurement system.

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VARIOHM Temperature Sensor Families

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Example Temperature Sensor Solutions

ETP-AM-SP-100

Industrial temperature probe with IP67 protection
NTC or PT1000 sensing technology
Temperature range: −40°C to +230°C

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LTP-SP-PT

RTD-based temperature probe
PT100 / PT1000 technology
Temperature range: −50°C to +150°C

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ETP-MO Series

Temperature probes for industrial processes
Available with NPT and M8 connections
Temperature range up to +230°C

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ETP-PC Pipe Clamp

Temperature sensor for pipe monitoring
NTC sensing technology
Temperature range: −40°C to +125°C

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Application-Specific Temperature Solutions

In addition to standard products, VARIOHM also provides customized temperature sensors for specialized applications including:

• Medical systems
• Hydrogen and energy systems
• Industrial equipment
• HVAC systems
• EV and battery systems

The ability to tailor the sensing element, mechanical structure and electrical interface allows optimal integration into complex systems.

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📊 Quick Selection Guide for Engineers

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The VARIOHM Temperature Sensor Landscape

The VARIOHM temperature sensing portfolio covers a broad range of applications – from surface temperature monitoring in electronics to temperature control in pipes, engines and advanced battery systems.

Solutions can be broadly categorized as:

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Surface Temperature Sensors

Sensors designed for direct contact with electronic components or mechanical surfaces.

Examples include:

• Ring Terminal Sensors
• Hex Bolt Sensors

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Screw-In Temperature Sensors

Threaded probes allowing direct integration into industrial systems, engines and mechanical assemblies.

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Tubular Temperature Probes

General-purpose probes suitable for a wide range of industrial and OEM applications.

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Pipe Temperature Sensors

Sensors specifically designed for pipe temperature monitoring using clamp or pipe-mount structures.

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Battery Temperature Sensors

Sensors optimized for battery monitoring in EV and energy storage systems.

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Frequently Asked Questions

What is the difference between NTC and RTD sensors?

NTC sensors offer very high sensitivity and fast response time, while RTD sensors provide superior long-term stability and high accuracy.

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How does sensor placement affect temperature measurement?

Improper placement can result in readings that do not represent the true system temperature.

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What is thermal response time?

It is the time required for a sensor to react to a temperature change.

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Do temperature sensors require calibration?

For high-precision measurement systems, periodic calibration is recommended to maintain accuracy.

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Conclusion

Reliable temperature measurement does not depend solely on the sensor itself.

It depends on the design of the entire measurement system.

Selecting the correct sensing technology, positioning the sensor properly and designing the thermal environment correctly are key factors that determine measurement reliability.

A high-quality sensor is only the starting point.

A well-engineered measurement system is what ultimately makes the difference.