Infrared Temperature Sensor vs Contact Sensors – Key Differences Explained
In industrial and scientific environments, the comparison of infrared temperature sensor vs contact sensors is often misunderstood, as the terms are sometimes used interchangeably. However, they are not the same. Understanding the differences between these two technologies is essential for selecting the right solution for temperature monitoring, process control, and safety. This guide explores how infrared temperature sensors and thermal sensors work, their key characteristics, and the applications where each is best suited.
Table of Contents
What Are Infrared Sensors?
Infrared (IR) sensors detect radiation emitted by objects above absolute zero. They are specifically designed to capture infrared wavelengths and translate that energy into an electrical signal. In industrial settings, this signal is processed to calculate the surface temperature of a material.
Key characteristics of infrared sensors:
- Non-contact measurement from a safe distance
- Extremely fast response time (milliseconds)
- High accuracy with proper calibration
- Ideal for moving targets and high-temperature environments
- Commonly used in steel, aluminum extrusion, glass, plastics, and food production
What Are Contact Sensors?
Contact sensors, on the other hand, are a broader category that includes devices like thermocouples, resistance temperature detectors (RTDs), and thermistors. These devices measure temperature through direct physical contact with the object.
Key characteristics of contact sensors:
- Contact-based measurement
- Typically slower response compared to infrared sensors
- Require physical installation in or on the material
- Highly reliable for stable, low-to-medium temperature applications
- Widely used in HVAC, refrigeration, environmental monitoring, and electronics
Key Differences Between Infrared and Contact Sensors
| Feature | Infrared Sensors | Contact Sensors |
|---|---|---|
| Measurement Method | Measurement Method Non-contact, detects infrared radiation | Contact-based, requires physical touch |
| Response Time | Milliseconds | Seconds |
| Durability | No wear from contact | Subject to wear/contamination |
| Best For | Best For High-temp, moving, or hazardous environments | Stable, low-to-medium temp conditions |
| Applications | Steel, aluminum extrusion, glass, plastics, food safety | HVAC, electronics, lab testing, refrigeration |
Choosing the Right Sensor
The decision between infrared and contact sensors depends on the specific industrial process:
- Use infrared sensors when speed, safety, and non-contact measurement are essential.
- Use contact sensors when direct, stable, and long-term monitoring of lower temperatures is required.
In many cases, industries combine both technologies—infrared pyrometers for real-time process monitoring and contact sensors for calibration or background measurement.
AST’s Expertise
At Accurate Sensors Technologies (AST), we specialize in designing infrared temperature sensors for demanding industrial applications. From aluminum extrusion to glass forming, our sensors provide precise, real-time measurements that improve quality and efficiency.
For processes that also rely on contact sensors, our solutions integrate seamlessly, offering complete temperature monitoring systems tailored to your needs.
Conclusion
While both infrared and contact sensors measure heat, their methods, applications, and advantages differ significantly. Infrared sensors excel in non-contact, high-speed, and high-temperature environments, while contact sensors remain reliable for stable, contact-based measurements.
To learn more about infrared temperature sensors and explore AST’s solutions, visit our Knowledge Hub and Product range.
To learn more about infrared temperature sensors and explore AST’s solutions, visit our
Frequently Asked Questions about Infrared Temperature Sensors
What are Infrared Temperature Sensors and how do they work?
Infrared Temperature Sensors are non-contact devices that detect the infrared radiation emitted by objects above absolute zero. Using specialized optics and detectors, they convert this radiation into an electrical signal that represents the object’s surface temperature. This allows accurate measurement without touching the object—essential for hot, moving, or hazardous environments.
What are the main advantages of Infrared Temperature Sensors compared to traditional contact sensors?
Infrared Temperature Sensors offer several advantages:
- Non-contact measurement – prevents contamination and wear.
- Fast response time – enables real-time monitoring in production lines.
- High versatility – suitable for metals, plastics, glass, food, and more.
- Low maintenance – since there is no physical contact, the sensor lasts longer.
Which industries use Infrared Temperature Sensors the most?
These sensors are widely applied in:
- Aluminum Extrusion – controlling billet and profile temperatures for quality output.
- Steel and Metals – monitoring casting, forging, and rolling.
- Glass Manufacturing – ensuring precise control during melting and shaping.
- Plastics – regulating extrusion and molding temperatures.
- Food Industry – verifying cooking and cooling processes safely.
What is the difference between Infrared Temperature Sensors and Thermal Cameras?
Both technologies detect infrared radiation, but they serve different purposes:
- Infrared Temperature Sensors – provide precise spot or surface temperature measurements, ideal for process control.
- Thermal Cameras – create a heat map of an area, making them useful for inspections, maintenance, and detecting anomalies.
However, thermal cameras have limitations in industrial temperature measurement:
- They operate within a limited infrared wavelength range.
- They cannot work simultaneously at dual wavelengths, which is often essential in harsh environments with dust, smoke, or steam.
Because of these limitations, thermal cameras are less suitable for many demanding industrial processes where precision and adaptability are required.
How accurate are Infrared Temperature Sensors?
Modern Infrared Temperature Sensors, such as those developed by Accurate Sensors Technologies (AST), achieve high levels of accuracy even in harsh conditions like dust, smoke, or vibration. Calibration and optical design ensure reliable readings across industries.
Can Infrared Temperature Sensors be customized for specific applications?
Yes. AST designs application-specific solutions to meet industry requirements. Whether it’s high-temperature steel casting, delicate glass processing, or aluminum extrusion, the right sensor configuration ensures optimal performance.
Why should industries choose Infrared Temperature Sensors over traditional contact sensors?
Unlike thermocouples or resistance temperature detectors (RTDs), Infrared Temperature Sensors do not require direct contact. This eliminates wear, reduces contamination risks, and ensures safety in extreme environments—making them the preferred choice for modern industry.
