How to Use Temperature Indicating Labels & Markers

How to Use Temperature Indicating Labels & Markers

There are many kinds of thermal labels and markers that are used for a variety of purposes in day-to-day life. The main purpose of using labels is to identify, tag, categorize, and give information about the product. Different types of labels and markers have different characteristics because of the different materials they are made of and different materials to be used on.

Temperature Indicating Labels & Markers described in this article can be divided into three categories: Temperature indicating labels, Temperature Plates, and Thermomelt Heat Sticks.


types of thermal labels

Temperature Indicator Labels are small, low-cost temperature indicator or time/temperature labels used during shipping, storage, or processing. Typical uses include monitoring the temperature of pharmaceuticals, chemicals, and fresh produce during transportation. The labels change color if there is a temperature excursion outside the preset limits.

Nowadays, there is a variety of temperature indicator labels, just choose a solution, depending on your need. Labels such as the Time-Temperature Indicator, High-temperature thermal labels, and the TempDot Time-Temperature labels will indicate if the temperature excursion exceeded a preset time. The Freeze Check Temperature Indicator and ColdMark Temperature Indicator are used in shipments to indicate a temperature excursion below 32°F (0°C). Used in commercial dishwashers, the TempDot High Temp Thermal Label will indicate if the final rinse has reached the HACCP required temperature of 160°F (71°C)

Types of Thermal Labels:

Three-to-Five-level temperature labels. High-temperature thermal labels are temperature indicator labels that are accurate, inexpensive, disposable heat indicators providing a permanent record of temperature changes. The irreversible temperature indicators come with one, three, five, or eight temperature steps, available from 90°F (32°C) to 500°F (260°C). Applications, where these temperature indicator labels can be used, include the manufacturing, processing, storage, shipping, monitoring the shelf temperature of heat-sensitive products, for dishwashers, heat sanitizing, ovens, dryers, and curing operations.

Time-Temperature Indicators. Time/Temperature Indicators are available in a variety of time and temperature ranges and may be used to monitor the cold chain for perishable food products, vaccines, blood, and many other applications. Monitoring temperature exposure of temperature-sensitive products during transportation and storage (for example, frozen or refrigerated foods, drugs, vaccines, medical diagnostic kits, blood, blood products, and intraocular lenses).

TempDot High-Temperature Dishwasher Thermal Labels are designed for use in commercial dishwashers and warewashers to ensure that the recommended sanitization temperature of 160°F (71°C) has been reached. These single-use temperature indicator labels can be adhered to dishes, glassware, silverware, pots, pans, or other kitchenware.

The Freeze Check Temperature Indicators are used to indicate an out-of-range temperature below 32°F (0°C). If an out-of-range temperature is reached, the irreversible temperature indicator changes from clear to white, and the check mark is no longer visible.

ColdMark Temperature Indicators are available in either 32°F/0°C or 26°F/-3°C, these stick-on temperature indicator labels can be applied to a product, package, carton, or master pack of items sensitive to extremely cold temperatures.

The irreversible labels provide a permanent record of the highest temperature reached on a piece of equipment. When the equipment reaches a certain temperature, the white area on the label turns irreversibly black, giving clear proof of the highest temperature attained. Irreversible Indicating Labels are preferably applied on a dry, clean surface for maximum effectiveness, but the strong adhesive reduces the possibility of labels falling off, even on dirty or uneven surfaces.



Temp-Plates indicators

Temp-Plates are self-adhesive temperature recording labels that can be read at a glance. Rated temperatures are printed at the sensor window. Each Temp-Plate contains one to several sealed heat-sensitive elements which change chemical structure when exposed to heat, exceeding their calibrated temperatures. Each pearl gray indicator turns permanently and irreversibly black in less than one second and with ± 1% accuracy. With proper installation, Temp-Plates resist exposure to solvents, fuels, grease, oil, water, and steam. Where exact temperature is critical, a Temp-Plate’s miniaturized size permits installation on parts and in areas where other recording instruments prove impractical. Temp-Plates provide a continuous monitor for overheat that does not distort the temperature of the item being measured. Temp-Plates are easy to apply. For use during testing, Temp-Plates can be removed and entered into the test record logbooks. They are available in a vast array of configurations and ranges. The scales include °C, or °F, or both.

Calibration Method

Temp-Plates are tested by placing test samples close to calibrated thermocouples installed on the surface of a special heavy-duty hot plate. A temperature rise rate not exceeding 1°C per minute is maintained and the temperature point where the color change occurs is carefully observed and recorded. 


Versatile, easy-to-read Temp-Plate Labels help monitor and prevent overheating of valuable machinery, electrical parts, electronic components, perishable goods, and other heat-sensitive materials and equipment. Temp-Plates are efficient tools for laboratory work, testing, and quality control. Temp-Plates:

  • Monitor overheating, wear, and friction in machinery parts, such as bearings, gear boxes, transmission housings, radiators, and heat exchangers.
  • Check overheating in electrical equipment, such as transformers, relays, generators, rectifiers, motor casings and bearings, underground power lines.
  • Audit overheated electronic parts, such as tubes, transformers, resistors, circuit boards, and transistors.
  • Monitor commercial aircraft for preventive maintenance, such as engines, hydraulic systems, wheels, tires, brakes, heating systems, and avionics.
  • Prevent heat-related deterioration of materials, such as pharmaceuticals, pacemakers, foods, chemicals, and film.
  • Protect computers and computer rooms, cargo compartments, blast tubes, rocket chamber walls, and bomb and ordnance storage areas.


thermomelt heat sticks

Using Thermomelt HEAT-STICK markers is a quick and low-cost method to accurately measure surface temperatures of various metals and equipment. Available in 88 Fahrenheit and 32 Centigrade temperatures, the stick-in-holder design provides convenience and durability for long-lasting use in the workshop or in the field. Surface uses: Steel and Iron.

Features & Benefits:

  • When the stick melts, the precise temperature is reached;
  • A long-lasting stick is 33% bigger than competition;
  • Accurate to within +/- 1% of Fahrenheit and +/- 3% Celsius rated temperatures, no need for sensor calibration;
  • Ideal for: pre-heating, post-weld heat treating, interpass temperature monitoring, and annealing;
  • Protective holder, shirt-clip, and adjustment ring prevents breakage and improves handling.

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