Frequently Asked Questions

At ThermoWorks, we are committed not only to providing our customers with the best quality and value in their temperature instruments, but in providing the kind of service and support you might expect from a business partner, not just a supplier.

That starts with a proper understanding of your tools and what they can do for you. Here are some answers to frequently asked questions about some of our more popular products.

If you don't see the answer you're looking for here, check our Learning Center or our Glossary of Temperature Terms or please don't hesitate to email us at or call us with your question at 801-756-7705 or 1-800-393-6434.


General Thermometry FAQs

How do I know when my food is done cooking?

It may seem like an obvious point, but a thermometer is just a tool that gives you information about the temperature of the food you are preparing. YOU have to make the decisions about when to increase or decrease the heat and about when things are done based on the information the thermometer gives. In most cases, you are looking for the lowest temperature reached in the thickest part of the food to judge doneness.

While different people like their meat or other food prepared to different levels of doneness, here is a chart of chef-recommended temperatures to get you started.

Where should I place my probe tip to gauge doneness?

When testing doneness in most cooked foods, the coldest part will be the very center of the thickest portion. With larger foods, you can take quick readings with your thermometer in several locations to verify that the entire portion is done. If you are chilling a food, the center of the thickest part will be the last to cool.

Keep in mind that different types of thermometers have sensors of different sizes. A dial thermometer can have a sensor as big as an inch long and your reading will be an average of the temperature of all the different materials touching that sensor. Most digital thermometers have small sensors at their tip. Penetrate the food you are checking with the probe and place the very tip of the probe where you want to measure.

How often should I calibrate my thermometer?

The word "calibrate" is often misunderstood to mean necessarily making some kind of adjustment to a thermometer for accuracy. While adjustments are sometimes needed, "calibrating" a thermometer simply means testing its accuracy against a verifiable standard. If the thermometer is within the accuracy specification listed by the manufacturer or quality control agency, no adjustment should be made.

When it comes to recommended frequency, there is a very wide range. Mechanical thermometers like dial thermometers should be calibrated very regularly if not daily, while digital thermometers are often only calibrated once a year. Check the manufacturer's recommendation for your particular type and model of thermometer or check with the appropriate health department or quality control agency with authority over your operation.

How do I calibrate my thermometer?

Again, the answer depends upon the requirements of the presiding health department or quality control agency. Many organizations, including corporations, require lab calibration of thermometers for professional use. ThermoWorks maintains a fully operational NIST-Traceable lab that can provide Certificates of Calibration at multiple points traceable to the National Institute of Standards and Technology (contact us at or ask for the calibration lab at 1-800-393-6434 or 801-756-7705).

While it is true that the most definitive test of a thermometer's calibration follows at least a 3-point method, the use of a properly made ice bath is a widely used test in the food industries and is recommended by the USDA and other agencies.

The most common error in an electronic temperature sensor is a shift in the base electrical value which can be seen in an ice bath test. If a digital thermometer has been once calibrated successfully at other temperatures, and it can be shown to read accurately in an ice bath thereafter, then the likelihood that it reads correctly at other temperatures is greater.

Why does my ThermoWorks thermometer show a reading higher than 32°F (0°C) when I put it in ice water?

Probably, because the temperature is higher than the ice point unless you take the time to create a properly made ice bath. If the thermometer is, in fact, outside of its published accuracy specification, adjust accordingly or contact our Service Department (, 1-800-393-6434 or 801-756-7705).

I'm having trouble turning my thermometer on, why?

Check the battery compartment. In many thermometers there is a small metal clip that holds the batteries in place. Even if the batteries are in place, if they are not under this little clip, the thermometer won't turn on. If the clip is in place and the thermometer still won't turn on, contact our famous ThermoWorks Service Department (, 1-800-393-6434 or 801-756-7705).

Why does my new ThermoWorks thermometer read 3-5 degrees different than my old thermometer?

Most likely, because your old thermometer is not as accurate as your new ThermoWorks digital thermometer. Test both thermometers in a properly made ice bath to check and adjust accordingly or contact our Service Department (, 1-800-393-6434 or 801-756-7705).

Why doesn't my ThermoWorks thermometer seem to settle on a final temperature in food? It keeps changing.

Typically, because the temperature of food keeps changing while it is cooking, and your ThermoWorks digital thermometer is accurate enough to see it. Thermometers don't "lock in" on a given reading unless they have a "hold" feature designed to do that.

Am I supposed to clean my ThermoWorks thermometer? How, and how often?

You should wipe the probe clean with cleansing wipes or soap any time it comes in contact with raw meat, and you should wipe the whole thermometer casing after each use being careful not to get it wet. Never put the housing of your digital thermometer near water unless it has an IP rating of 66 or higher.

What is an IP Rating?

One common added feature for electronic thermometers, particularly electronic cooking thermometers, is a splashproof or waterproof rating.

The International Electrotechnical Commission (IEC) has created a standard for rating instruments based on their ability to protect their electronic components from corrosion by water or dust. The International Protection Rating code (or IP code) consists of the letters "IP" followed by two numbers.

The first number tells you how protected an instrument's electronics are from penetration by solids (like dust) and the second number tells you how they stand up against liquids according to the following table:

  First number
Protection against solid objects
  Second Number
Protection against liquids
0 No protection 0 No protection
1 Protected against solids objects over 50mm (e.g. accidental touch by hands) 1 Protected against vertically falling drops of water
2 Protected against solids objects over 12mm (e.g. fingers) 2 Protected against direct sprays up to 15° from the vertical
3 Protected against solids objects over 2.5mm (e.g. tools and wires) 3 Protected against direct sprays up to 60° from the vertical
4 Protected against solids objects over 1mm (e.g. tools, wires and small wires) 4 Protected against sprays from all directions - limited ingress permitted
5 Protected against dust - limited ingress (no harmful deposit) 5 Protected against low pressure jets of water from all directions - limited ingress permitted
6 Totally protected against dust 6 Protected against strong jets of water e.g. for use on shipdecks - limited ingress permitted
    7 Protected against the effects of temporary immersion between 15cm and 1m. Duration of test 30 minutes
    8 Protected against long periods of immersion under pressure

If, for example, a thermometer had a rating of "IP65," that would mean that it was tested and found completely protected against dust as well as protected against low pressure jets of liquid from all sides, but NOT protected against immersion, or an accidental drop into the soup!


Food Temperature FAQs

Why do I get different readings when I measure my food in different places?

Because the temperature of the food can be different in different places at the same time. It is not unusual for the internal temperature of a large roast or turkey to vary by as much as 20 to 30°F (10 to 15°C) throughout the meat or bird. Even a steak or a boneless chicken breast may show differences of many degrees as you move the tip of your thermometer probe from the surface toward the center of the piece, or from end to end, depending upon the speed and accuracy of your thermometer.

Why did my steak come out medium well when my ThermoWorks thermometer reading suggested medium?

Because meat will continue to cook after you take it off the heat. This is called "resting." Cooked meat should be allowed to "rest" after cooking and before cutting. This permits the juices to be reabsorbed into the fibers of the meat. If you skip resting, you will lose more flavorful juices when the meat is cut. The temperature of the meat will always continue to rise a little during the resting period. Typically, even a small steak or individually cooked piece of chicken will rise at least three or four degrees during resting. A larger roast or turkey can rise as much as ten to fifteen degrees depending upon conditions. So you should remove your meat from the oven or grill prior to reaching your target doneness temperature. Otherwise, it will be overcooked.

Why is my chicken still bloody when my ThermoWorks thermometer says it's done?

Because the bone marrow in chicken bones can release blood while cooking. If the chicken has reached at least 160°F (71°C) for five minutes or more, it is safely done. (For more information, see

What are the critical food safety temperatures?

The USDA publishes temperature guidelines for food holding and cooking (look for "Food Safety Tips" at You can use your ThermoWorks thermometer to check temperatures and minimize food-borne illness in your kitchen. Bacteria thrive between the temperatures of 40°F (4.5°C) and 140°F (60°C). Food should not be stored between these temperatures for extended periods of time. Some leftover foods must be reheated to minimum temperatures to assure sufficient "kill rates" of bacteria or parasites.

Holding hot foods ...............................140°F (60°C) or higher
Holding cold foods ................................ 40°F (4.5°C) or colder
Fridge temperature.............................. 40°F (4.5°C) or colder
Freezer temperature ................... 0°F (-18°C) to -10°F (-23°C)

See also our chart of chef-recommended temperatures.

What special precautions do I need to take when using a thermometer near a grill?

Never leave a thermometer inside an oven, grill, smoker, or microwave while cooking unless it is specifically designed for this. Don't leave your thermometer on the grill hood or close to an open flame. Some probes are designed to be left inside an oven or grill, but the thermometer housing itself (where the electronic components are kept) typically needs to be kept cool and should only be brought near heat for short periods of time. When checking temperatures above a grill or fire, be careful that the thermometer body does not get too hot.


Thermapen FAQs

Where can I buy the Thermapen?

You can buy it right here online. There are only a few authorized dealers, (watch out for counterfeit Thermapen look-alikes). There are a few retail outlets in the U.S. and Canada that stock the Thermapen.

Why don't more retail outlets carry it?

Most retailers want to more than double their money. The big name chains want the most. If a product costs them $4, they want to charge you $10. The Thermapen is already priced at "Trade Pricing". Meaning, this is the price we sell it to commercial food service users and health departments. And, we offer it to the general public at the same price. Big retail chains would have to charge you much, much more and they'd still be mad that we would take your order at a lower price. The retailers that do carry the Thermapen are not making their normal mark-up so thank them if you buy there!

Where can I buy replacement batteries?

The Classic Thermapen uses two coin cell batteries, CR2032. Thermapen ONE uses one AAA battery. These batteries are commonly found at Wal-Mart, Target, and other stores. You can also order spare batteries from us.

How long should the battery last?

The Thermapen batteries are rated for 1,500 to 2,000 hours of use depending on Thermapen model. In the battery compartment you can enable and disable the auto-off feature. The auto-off feature will extend the life of the batteries. See owner's manual for details.

Will the Thermapen tell me when my meat is done?

Not exactly. Instead it (very quickly) tells you the actual temperature and you decide if that is "done". We can give you the USDA guidelines for food safety but you should consult your favorite cookbooks, TV shows and recipes for advice not only on safe temperatures but the best cooking temperatures for flavor and texture. Also remember that individual preference is very important.

Other digital cooking thermometers are cheaper. Why pay more for a Thermapen?

In use there's a big difference. Don't take our word for it. Check our Reviews page to read the many reasons written by others. Cheaper thermometers are limited by the technology that they use. These can be mass produced for just a few dollars. On the other hand, the Thermapen is hand-assembled and hand-tested and uses a professional thermocouple circuit design. This design costs more to make than the cheap thermometers.

Why is the Thermapen so much faster than other cooking thermometers?

The main reason is the professional thermocouple technology that we use instead of mass-produced thermistor technology. Thermocouples are recommended by the USDA for measurement of cooked meat products and thin portions. Go here to see what a thermocouple means in performance vs. a thermistor. We also use a reduced-diameter needle tip on the probe. Comparable professional meters cost $140 to $300 for the electronics and a similar probe! Some improvements were made in the sensor manufacturing process and the probe assembly in the new Splash-Proof Thermapen to make it just slightly faster than the original Super-Fast Thermapen.

Why don't you have a left-handed Thermapen?

Interesting question. My wife Suzette is left-handed and she's always thought the opposite. She prefers to use her dominant hand to wield the roasting pan, grasp the food with tongs, stir, or whatever else she's doing in combination with the one-handed temperature measurement. Thus, in her opinion, it's best to hold the Thermapen in her right hand while she uses her dominant hand for the other tasks.
Don't buy that? While the Thermapen isn't quite as ambidextrously switchable as a screwdriver or a hammer, it's pretty close. It can easily be gripped in a number of ways. I hold my Thermapen in both my left hand and right hand depending on what I'm doing. Still I empathize with anybody who's left-handed and wishes the Thermapen were reversed. So, if our engineers can ever figure out a no-cost way to do that in the next Thermapen, we'll consider doing it. Meanwhile, switch-hit.


Infrared FAQs

Can I Use My Industrial Infrared Thermometer for Human Temperature?

All of the infrared thermometers that we sell are industrial units. WAND is designed specifically for taking human temperatures.

Can I check my grill temp with an infrared thermometer?

If you aim an infrared thermometer at a porous surface like a grill or grate, it will factor in the surface temp of whatever surfaces are visible through the holes of the grill or grate when calculating a final temperature for your reading.

To accurately measure the temperature of a porous grate or grill, place a solid surface like an iron plate or skillet on the grill, let it come to temperature and measure the plate or skillet. Spray a little cooking oil on the plate or skillet to ensure proper emissivity.

What is emissivity?

"Emissivity" is a measure of a material's ability to emit infrared energy. It is measured on a scale from just above 0.00 to just below 1.00.

Generally, the closer a material's emissivity rating is to 1.00, the more that material tends to absorb reflected or ambient infrared energy and emit only its own infrared radiation. Most organic materials, including the byproducts of plants and animals, have an emissivity rating of 0.95.

Check your infrared thermometer to see if it has adjustable emissivity settings as a feature. Then check your target material against this ThermoWorks Emissivity Chart.

Can I check my meat or other foods for doneness with an infrared thermometer?

Since infrared thermometers only measure surface temperatures, they are not very effective at gauging the doneness of foods. Use traditional probe thermometers for this.

When using an infrared thermometer with liquids like soups and sauces, be sure to stir vigorously before taking a measurement to more closely approximate the internal temperature of the liquid. Be aware that steam, even when a liquid is not boiling, can condense on your thermometer and affect the accuracy of your measurements.

Can infrared thermometers see through glass or clear plastic?

Infrared thermometers do NOT "see through" glass, liquids or other transparent surfaces even though visible light (like a laser) passes through them—i.e. if you point an IR thermometer out a window, you will be measuring the surface temperature of the window itself.

Do infrared thermometers see through water?

No. Infrared thermometers can only measure the surface temperature of water.

What is "spot size," "spot ratio" or "distance to target ratio"?

The "spot size" of any given measurement is controlled by two variables:

  1. the "distance to target ratio" or "spot ratio" of your particular infrared thermometer
  2. the distance between your infrared thermometer and the target

Typically listed on the thermometer itself, the "distance to target ratio" (DTR) or "spot ratio" tells you the diameter of the "circle" of surface area an IR thermometer will measure at a given distance.

For example, an infrared thermometer with a 12:1 ratio will measure the temperature of a 1" diameter circle of surface area from 12" away, a 2" diameter circle of surface area from 24" away, and so on.

Do I need to clean my infrared thermometer?

To be accurate, infrared thermometers must be kept free of dirt, dust, moisture, fog, smoke and debris. Always take the time to clean your infrared thermometer after exposure to dirty, dusty, smokey or humid conditions. You should also plan a regular cleaning every six months or so. Particular care should be taken to keep the infrared lens or opening clean and free of debris.

To clean your infrared thermometer:

  1. use a soft cloth or cotton swab with water or medical alcohol (never use soap or chemicals)
  2. carefully wipe first the lens and then the body of the thermometer
  3. allow the lens to dry fully before using the thermometer

Never submerge any part of the thermometer in water.

How do I turn the laser on?

It depends upon the particular model of infrared thermometer. Consult the user's manual that came with your thermometer for the full range of features and how to use them.

Why am I getting weird readings on shiny metal?

Substances with very low emissivity ratings, like highly-polished metals, tend to be very reflective of ambient infrared energy and less effective at emitting their own electromagnetic waves. If you were to point an infrared thermometer with fixed emissivity at a stainless steel pot filled with boiling water, for example, you might get a reading closer to 100°F (38°C) than 212°F (100°C). That's because the shiny metal is better at reflecting the ambient radiation of the room than it is at emitting its own infrared radiation.

Some infrared thermometers have fixed emissivity settings of (usually of 0.95 or 0.97) to simplify their operation while leaving them suitable for most material surfaces, including almost all foods.

But other infrared thermometers come with adjustable emissivity settings, so you can more accurately prepare your thermometer for the type of surface being measured, particularly when measuring non-organic surfaces.

Can I calibrate my infrared thermometer myself?

Infrared thermometers can be calibrated for accuracy just like other thermometers. In calibration labs (like the NIST-Traceable ThermoWorks Calibration Laboratory in American Fork, Utah), technicians use industrial black bodies (like the IR-500 Portable IR Calibrator) to calibrate infrared thermometers (contact us at or ask for the calibration lab at 1-800-393-6434 or 801-756-7705).

If neither an industrial black body or a comparator cup are available, however, you can do a quick calibration using a properly made ice bath.


Data Logger FAQs

Where's my logger software?

Each logger system comes with its own proprietary software. You can download the software for your logger by finding you logger system on our Software Downloads page.

Why didn't my logger come with a user's manual?

Some of our logger systems don't come with a physical copy of the user's manual, but all ThermoWorks user's manuals can be downloaded directly from the individual product pages on this website.

Either find your particular data logger page on our Data Logger Index or use our User Manual Locator here and then look for the PDF download of your particular user's manual.

How do I download my logger data to my computer?

Some of our data logging systems come with built-in USB connectors or wireless capability that can connect directly with your computer but many logging systems require the purchase of a separate "cradle" or data aggregator that connects directly with your computer (usually through your USB port).

Why isn't my data logger working?

The most common problem with getting your loggers up and running is loading the right drivers. This can usually be determined by looking in the System Device Manager on your PC.

Another common problem is failure to install the proprietary software and register each logger unit before installing them. If you need help, please don't hesitate to contact our Service Department (, 1-800-393-6434 or 801-756-7705).

Do I have to set my logger up before using it?

Yes. Some of our data loggers come with preset defaults and are ready to use right out of the box but others will only work once they've been set up by selecting settings directly on the logger unit or by using a computer-driven wizard and registering each unit with the controlling software. Even units with preset defaults should be customized to your particular needs (high and low alarms, frequency of measurements, etc.) before use.

How do I tell multiple loggers apart in my data spreadsheet?

One of the key settings for your logger units is to give each different unit a name to differentiate it from the other units on the same network. Most people use either a number or a location or type of material being measured to name their loggers (i.e. "logger1" or "upper_freezer" or "raw_fish").

Will loggers work on Macintosh computers?

All of our loggers use proprietary software written for the PC. They will not work on the Macintosh operating system but will work on a Macintosh running a PC emulator like Parallels, CrossOver or Virtual PC.