When you’re trying to get food on the table or you want to get those burgers on buns for guests at a backyard barbecue, you want to do it as fast as possible — safely.

The best way to do that is by checking the temperature of your food with an instant-read thermometer. When you’re looking for a good thermometer that checks temps fast and accurately, you want to consider the “response time.”

Why FAST matters in an instant-read thermometer?

Instant-read thermometers are widely used by folks who like to barbecue or grill. If you’ve ever spent time flipping burgers or turning brats over an open flame, you know how the temperature of the food on the grill changes fast and fluctuates — that makes it challenging to get temperature readings, making an instant-read thermometer an important tool in your barbecue arsenal. 

You don’t want to leave your meat to slower thermometers — they can wreak havoc on grilling plans, here’s why:

What are time constants and full reading time?

Time constants and full reading time are concepts related to the speed and performance of thermometers.

Both time constants and full reading time are important considerations when evaluating the performance of a thermometer, especially when food safety is a priority. A thermometer with a shorter time constant and faster full reading time provides more timely and accurate temperature readings.

Each time constant represents the time it takes for the instrument to reach 63.2% of its final value. By multiplying the time constant by five, you can estimate the full reading time, which is the duration required for the instrument to reach a stable and accurate temperature reading.

For example, the full reading time of Typhur InstaProbe is 0.5s, which means the technical response time of the InstaProbe is 0.15s (time constant).

You can check the full review of Typhur InstaProbe.

Thermometer time constants

When you choose an instant-read thermometer, you must check whether its speed time claimed is full reading time or time constant.

How does temperature measurement work?

Temperature measurement relies on different principles and technologies, depending on the specific type of thermometer being utilized.

Below, we focus on thermocouple thermometers. This technology is commonly used in instant-read meat thermometers.


Thermocouples work by measuring thermoelectric potential to determine temperature. Based on the principle of the thermoelectric effect, they utilize the potential difference generated at the junction of two dissimilar metals to achieve temperature measurement.

The working principle of a thermocouple is evident in the image below. It comprises two metal wires, Wire Type A and Wire Type B, made of different materials. As the temperature increases at the junction of the left wires, the gauge on the right displays the corresponding temperature change clearly.

thermocouple thermometers
Source: https://www.iqsdirectory.com/articles/thermocouple.html

The application of thermocouples on instant food thermometers

The design of instant-read meat thermometers you can find on the market now is shown in the diagram below:

  • 21: Needle tip tube body
  • 221: Thermocouple Junction
  • 22: Thermal Conducting Material
  • 23: Metal Wires of the Thermocouple
thermocouple application in instant read thermometer

When a probe, like the one shown in the image above, is inserted into food, heat undergoes a two-step conduction process: from the needle tip and tube body (21) to the thermal conducting material (22), and finally to the thermocouple junction (221). This sequential conduction introduces a time delay before reaching the thermocouple junction.

So, is there any chance to optimize the reading speed? The answer is YES!

World’s fastest instant-read thermometer: 0.5s full reading time

While researching ways to improve the response speed of the thermometer, Typhur’s product development team discovered that to enhance the response speed, it is necessary to reduce the response time for thermal conduction to reach the thermocouple junction.

What is DTCI technology?

The InstaProbe’s thermocouple is soldered to the tip, allowing for direct contact with the heat source. This integration technique is known as Direct Contact Thermocouple Integration (DTCI™), which is the main difference between InstaProbe and other instant-read thermometers on the market.

The development team applied DTCI to optimize the InstaProbe’s design and improve the response speed. When soldering the thermocouple junction onto the probe’s needle tip, one part is on the needle tip itself, while the other part is within the needle tip tube. The direct contact of the junction with the heat source allows for a rapid response to temperature changes through thermal conduction, bypassing the needle tip tube and thermal conducting material.

instaprobe thermocouple design

The probe’s tube body is filled with thermal conductive silicone grease. Without this filling, the heat source would come into contact with air after passing through the junction — air has much slower thermal conductivity compared to metal.

As a result, Typhur InstaProbe takes a full reading in 0.5 seconds or less. It’s the world’s fastest instant-read thermometer ever seen — typical digital thermometers available on Amazon or at big box stores take 10 or 15 seconds for a full reading and your grandma’s dial thermometer can take even longer.

How to verify the response time of your thermometer?

To test the response time of your instant-read meat thermometer, you can prepare an actual timer and an ice bath and following these steps:

  1. Prepare an ice bath

    Fill a container with ice and add cold water. Stir the mixture to ensure a consistent temperature.

  2. Set up the thermometer

    Calibrate and ensure your instant-read meat thermometer is ready for testing. Refer to the manufacturer’s instructions for any specific setup requirements.

  3. Start the timer

    Begin the timer simultaneously by inserting the thermometer probe into the ice bath. Note the exact starting time.

  4. Monitor the temperature change

    Watch the thermometer’s display as the temperature reading gradually decreases. Continue to monitor until the temperature stabilizes at 32°F (0°C).

  5. Stop the timer

    Once the temperature stabilizes at 32°F (0°C) on the thermometer, (i.e. for InstaProbe, since the accuracy spec is ±0.5°F (0.3°C), you should stop the timer with the display reaching 31.5°F~32.5°F (or 0.3°C).  Stop the timer and note the elapsed time.

  6. Calculate the response time

    Subtract the starting time from the stopping time to calculate the response time of your instant-read meat thermometer.


When you are shopping for thermometers, the speed of response is an important factor to consider. Different thermometer technologies have varying response times, and even a few seconds can have a significant impact depending on the specific application.

Some manufacturers may focus on time constant specifications, which may not accurately reflect the full reading capability comparable to the Typhur InstaProbe.