When to Use (and When Not to Use) a Non-Contact Thermometer

Non-contact thermometers take rapid measurements of surface temperatures. Their combined speed and ease of use make them invaluable tools for HVAC, manufacturing, and foodservice industries (to name a few). There are times when using a non-contact thermometer is ideal; BUT – you need to be aware of several important exceptions.

This article explains the right situations to use a non-contact thermometer and some limitations when performing temperature measurements.

Why Use a Non-Contact Thermometer

Non-contact thermometers are handy tools for taking surface temperature measurements from a distance. They can provide accurate measurements without ever having to touch the item you wish to measure. Six reasons to use a non-contact thermometer over a probe thermometer include:

1. Hazard Prevention
   A non-contact thermometer is an ideal tool to measure the surface of an item that is too dangerous to touch. Examples include; extremely high-temperature surfaces or machine parts.
2. Measuring Solid Objects
   Use a non-contact thermometer when items are entirely impenetrable, and a probe thermometer would not work. Examples include measuring frozen food.
3. Checking Fragile Items
   A non-contact thermometer is suitable when touching the item might cause it to become damaged or break. Examples include; computer circuitry.
4. Measuring Out of Reach Surfaces
   Use a non-contact thermometer over a probe thermometer when you need to know the temperature of surfaces that are too high or simply out of reach. Examples include air conditioning outlets and tight spaces.
5. Sterile Environments
   A non-contact thermometer is perfect for measuring the surface temperature of any items susceptible to contamination—for example, surfaces in laboratories and processed foods.
6. Moving Parts
   Moving machinery parts are prime candidates for non-contact thermometer measurement as temperatures can be assessed without stopping work. Examples include measuring moving conveyor belts, elevators and gears.

Limitations of Non-Contact Thermometers

With all the great examples of use for non-contact thermometers listed about you might be thinking, “Why would I ever need any other type of thermometer?”. Although non-contact thermometers are fantastic in some applications - they do have some drawbacks. Our scientists list five critical limitations of non-contact thermometers below.

1. Non-contact thermometers are great for checking surface temperature; however, they do not measure the internal temperature of an object.
2. Non-contact thermometers require adjustments when measuring particular objects and materials, such as shiny and reflective objects. For more information on emissivity, read our article “ How do non-contact thermometers work?”.
3. Non-contact thermometer measurements can be impacted by moisture, dust, fog, smoke or other particles in the air.
4. Non-contact thermometers need time to acclimatise after rapid changes in ambient temperature.
5. Non-contact thermometers do not “see-through” glass, liquids or other transparent surfaces—even though the visible laser pointer light might pass through them. So, if you try to point a non-contact thermometer at a window, you will measure the window’s glass, not the outside temperature.

Non-Contact Thermometer Product Examples

Testo 810 2in1 IR thermometer Product code: IC-0560-0810 The Testo 810 non-contact thermometer allows the simultaneous measurement of the air temperature and surface temperature of the object measured.   Ideal for: Use in the heating, ventilation and air conditioning trade.   Specifications IR Measuring range: -30 to +300°C Accuracy: ± 2.0°C (-30 to +100°C) ± 2% of mv Resolution: 0.1°C Laser pointer:  1 point laser

Testo 830-T2, 2 Laser Point InfraRed (IR) Thermometer Product code: IC-0560-8312 The Testo 830-T2 Non-contact thermometer takes touch-free measurements using the IR sensor and contact measurements thanks to the type K thermocouple input. The unit features an ergonomic pistol grip plus visual and audible alarms to alert users when measurements exceed thresholds.   Ideal for: The IC-0560-8312 is the perfect tool for HVAC, maintenance, mechanical and automotive applications.   Specifications IR Measuring range: -30 to +400 °C Accuracy: ±1.5 °C or ±1.5% of mv (+0.1 to +400 °C) ±2 °C or ±2% of mv (-30 to 0 °C) the higher value applies Resolution: 0.1°C Laser pointer: 2 point laser

FLUKE 62 MAX IR Thermometer Product code: FLUKE-62-MAX The Fluke 62 MAX is compact, highly accurate, IP54 rated for dust and water resistance, and easy to use. Precise yet rugged enough to take a 3-meter drop, the Fluke 62 MAX is built to thrive in industrial environments.   Ideal for: The Fluke 62 MAX is an easy to use surface measuring tool in heavy industrial, electrical, HVAC, and mechanical environments.   Specifications IR Measuring range:  -30 C to 500°C Accuracy: ≥0 °C: 1.5 C or 1.5% of reading, whichever is greater -10°C to 0°C: 2.0 -30°C to -10°C: 3.0 Resolution: 0.1°C Laser pointer: 1 point laser

Waterproof Infrared & Probe Thermometer Product code: IC-0560-1040 The waterproof IC-0560-1040 combines an accurate non-contact thermometer with a fold-out probe thermometer. The IC-0560-1040  can probe into a product to ensure the temperature is consistent throughout, making it suitable for scanning surface temperatures of individual food items or incoming boxes and pallets.   Ideal for: This HACCP compliant thermometer is suitable for all facets of the food and beverage industry, from manufacturing and professing to kitchens and food preparation.   Specifications IR Measuring range: -30 +250 °C Accuracy: ±2.5 °C (30.0 to 20.1 °C) ±2.0 °C (20.0 to 0.01 °C) ±1.5 °C or ±1.5 % of the measuring value (+0.0 to +250.0 °C) Resolution: 0.1°C Laser pointer: 2 point laser

Conclusion

A non-contact thermometer is an excellent measuring tool for a range of applications. However, it is essential to know the limitations of non-contact thermometers to ensure accurate results.

If you need help finding the best thermometer for your needs, speak with an Instrument Choice Scientist! Call 1300 737 871 or email customer-service@instrumentchoice.com.au.