Forehead thermometer with both no touch and touch functions. Designed with convenience in mind, it allows you to take a measurement in only a couple of seconds by aiming in the middle of the forehead, in between the eyebrows.

Braun NTF3000 digital No touch Forehead Thermometer:

• Quick & Easy, no struggle or stress
• No touch mode
• Touch mode
• Colour-coded temperature guidance
• Silent mode for middle-of-the-night readings
• Backlight for night time reading
• Clinically-proven accuracy
• Positioning guidance system

Braun no touch Forehead Thermometer

A Braun NTF3000 digital No touch Forehead Thermometer:

This thermometer is intended for household use only. The use of this thermometer is not intended as a substitute for consultation with your physician.

Temperature elevation may signal a serious illness, especially in newborns and infants, or in adults who are old, frail, or have a weakened immune system.

• Please seek professional advice immediately when there is a temperature elevation and if you are taking the temperature on:
  • Neonates and infants under 3 months (Consult your physician immediately if the temperature exceeds 99.4°F)
  • Patients Over 60 years of age (Fever may be blunted or absent in older patients)
  • Patients having diabetes mellitus or a weakened immune system (e.g., HIV positive, cancer treatment, chronic steroid treatment, post-surgery)
  • Patients who are bedridden (e.g., nursing home patient, stroke, chronic illness, recovering from surgery)
  • A transplant patient (e.g., liver, heart, lung, kidney)

This thermometer is not intended for pre-term babies or light-for date babies.
This thermometer is not intended to interpret hypothermic temperatures.

Do not allow children below 12 years to take their temperatures unattended.
Please consult your doctor if you see symptoms such as unexplained irritability, vomiting, diarrhea, dehydration, changes in appetite or activity, seizure, muscle pain, shivering, stiff neck, pain when urinating, etc., even in the absence of fever.

Even in the absence of fever, those who exhibit a normal temperature may still need to receive medical attention. People who are on medication should not be assessed solely on temperature readings to determine the severity of their illness.

Do not modify this equipment without the authorization of the manufacturer.

Braun ntf3000 review

Why Braun No touch + forehead thermometer?

• Measurement in under 2 seconds: The innovative infrared technology measures forehead temperature in under 2 seconds, whether you use the touch or no-touch option.
• Accurate and reliable: Due to the unique technology, the Braun No touch + forehead thermometer captures the heat naturally given off by the forehead to calculate the temperature. Get the same professional accuracy whether touching your child’s forehead with the thermometer or holding it up to 2 inches (5 cm) away.
• Easy to use: The Braun No touch + forehead thermometer is non-invasive. A measurement can be taken even while a child is sleeping. The Braun No touch + forehead thermometer is less threatening to a child than a rectal thermometer and easier to use than other methods.
• Safe and hygienic: No-touch option helps minimize the spreading of germs. Safe for use on children and adults

• Braun ntf3000 manual
  1. Power button
  2. Temperature button
  3. LCD display
  4. Scanner
  5. Silemt mode switch
  6. Battery door
  7. Guidance light
  8. Protective cap

Braun forehead thermometer instructions

How does Braun No touch + forehead work?

The Braun No touch + forehead thermometer measures infrared energy radiated from the skin at the center of the forehead area. This captured energy (which is twice as much thermal energy compared to a traditional forehead thermometer: A traditional forehead product without any optical system to capture radiated heat), is collected through the sensor and converted to an oral equivalent temperature value.

The Braun No touch + forehead thermometer has been clinically tested and proven to be safe and accurate when used in accordance with its operating instruction manual.

How to use your Braun No touch + forehead

How to use your Braun No touch + forehead:

1. Remove cap
   • Remove cap
2. Power on
   • Press and release the power button once. The backlight will come on and the start-up sequence starts
3. Ready
   • When the device is ready and correctly positioned, a horizontal line of dashes (“—”) will appear on the screen.
4. Position
   • Position devise on or up to 2 inches (5 cm) away from the center of the forehead, just between the eyebrows. For no-touch readings, the yellow guidance light will show you where you are aiming. If the eyebrow area is covered with hair, sweat, or dirt, please clean the area and then wait 10 minutes to improve the reading accuracy.
     It is important to hold the thermometer and the forehead steady during measurement. The movement will impact the temperature reading.
5. Take temperature
   • Press the temperature button (you can press and hold the button or press and release it). When the device is placed correctly, the screen displays a dashed line animation while it takes a reading. After the animation sequence (under 2 seconds), the display shows the temperature. The appropriate backlight color is displayed on the screen and the confirmation beep is heard.
     If the device is positioned too far away from the forehead, it will prompt you to move closer by displaying the letters “FWD.” Slowly move the device toward the forehead until the dashed line animation starts and a reading is displayed.
6. Read temperature
   • Remove the device and read the temperature. For no backlight and green backlight readings, you will hear a single long beep for 2 seconds. For yellow and red backlight readings, you will hear 10 short beeps. To repeat Go to step 4.
7. To turn off
   • Press the power button to turn off. The device will also shut off automatically after 60 seconds of no us

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This year is a favorable time for the thermometer manufacturing industry. With the sudden spurt in demand for medical thermometers, manufacturers are struggling to keep up with supply.

What are the best-infrared thermometer manufacturers in the USA?

The best thermometers will be those that use technology to connect our electronic devices with medical devices.

Crucial to the market’s growth will be continuous technological innovations, developments, and the launch of advanced electronic variants.

The connection between body temperature and disease makes medical devices the most important aspect of everyday doctoring.

American-made medical thermometer

The demand for medical devices is largely driven by the search for quality products that are easy to use at home.

However, while downstream trends can affect demand for thermometers, the most important factor in determining industry revenue is the price of thermometers.

Producers in this industry mainly manufacture temperature control devices, such as digital thermometers, infrared thermometers, medical thermometers, oral thermometers, body thermometers, electronic temperature monitors, and temperature strips.

This publication covers the best-selling digital thermometers and their market shares.

Medical infrared Thermometer manufacturers in USA

Thermometers are an essential part of every home first aid kit. While high temperature is our body’s way of fighting off disease, a long-term high fever is potentially dangerous and even deadly. Therefore, an accurate and high-quality thermometer plays a crucial role in monitoring fevers.

In general, digital thermometers are more reliable and safer to use—and smart options add additional helpful features. Take an in-depth look at the best digital thermometers so you can make the best choice for your home’s needs.

Some of the key companies in the thermometer manufacturing market include the following US-based corporations:

• American Diagnostic Corporation
• Amplim Labs
• Braun medical products
• Exergen Corporation
• Innovo Medical
• Welch Allyn
• Fluke Corporation
• Vigorun Thermometer

American Diagnostic medical thermometer

ADtemp 429 digital ear thermometer

What is American Diagnostic Corporation (ADC)?

American Diagnostic Corporation (ADC) is one of the world’s premier manufacturers of medical diagnostic products, medical devices, medical sensors, and accessories for the healthcare industry. The facility in Hauppauge, New York, houses the corporate offices, customer service, quality control, manufacturing, and distribution departments.

Thermometer Medical use (ADtemp 429): This thermometer measures infrared energy radiated from the eardrum and the surrounding tissue. This energy is collected through the lens and converted to a temperature value.

The measured reading obtained directly from the eardrum (Tympanic Membrane) can ensure the most accurate ear temperature. Measurements taken from the surrounding tissue of the ear canal generate lower readings and may result in the misdiagnosis of a fever.

• ADtemp 429 Thermometer specifications:
  • The new Adtemp 429 is a non-contact thermometer featuring an infrared sensor that reads temperature from the middle of the forehead.
  • The infrared sensor simplifies temperature measurement, ideal for detecting fever.
  • Measures in about 1 second without patient contact eliminating the concern of cross-contamination.
  • The measurement feedback system signals the proper operating distance for accuracy.
  • Measures at a distance of 4-6cm (1.5 “-2.5”) from the patient’s forehead.
  • Dual-mode – body, and object.
  • The large backlit LCD display is easy to read.
  • Wide Temp Range.
  • Fahrenheit-Celsius switchable.
  • The auto-off function after 30 seconds of conserves the battery life of the thermometer.

Innovo medical thermometer

Innovo Forehead and ear Thermometer

What is Innovo Medical?

Innovo Medical is a privately-held company located in Stafford, TX primarily involved in the design and manufacturing of Medical Products.

Product safety and reliability should be the fundamental guiding principle in the making of all medical products.

Forehead Thermometer medical use:

Forehead thermometer medical use: Get precise readings with the Innovo Medical forehead and ear temperature and fever health alert clinical monitoring system for children and adults.

CE and FDA Cleared.

This robust device, once only available to doctors, clinics, and medical professionals, makes it easy to get accurate temperature temperatures in the home setting.

The Innovo Dual Mode Thermometer allows you to choose between the ear mode, recommended for ages above one-year-old, and the forehead mode, ideal for all ages.

• Innovo Thermometer specifications:
  • Get your readings instantaneously with the push of a button.
  • No start-up, no waiting, just results when they are needed most!
  • No more sticking thermometer into your mouth and waiting ages to take a reading!
  • Perfect for use for those with restless kids.
  • Switch between Ear mode and Surface mode to best suit your needs!
  • The multipurpose infrared lens allows the user to accurately measure the surface temperature of baby bottles, running water, and more!

Welch Allyn medical thermometers

Welch Allyn 690 thermometer

What is Welch Allyn Medical device company?
Welch Allyn, Inc. was founded in 1915 and is an American manufacturer of medical diagnostic devices and patient monitoring systems. Headquartered in Skaneateles Falls, New York.

Thermometer medical use: Help your facility improve staff productivity and patient safety with the SureTemp Plus 690 Electronic Thermometer.

The SureTemp 690 Thermometer is fast—capturing approximately 4- to 6-second oral, 10- to 13-second rectal or pediatric axillary, and 12- to 15-second adult axillary temperatures.

Featuring the technology that sets the standard for accuracy, you can have confidence the SureTemp 690 will deliver accurate, repeatable readings on patients of all age groups.

• Welch Allyn Thermometer specifications:
  • Quickly captures accurate readings on all patient types
  • Last temperature recall button
  • Optional security wall mount
  • Takes approximately 6,000 readings on 3 AA batteries
  • Interchangeable, removable wells to help reduce the risk of cross-contamination
  • Large LCD displays temperatures in Fahrenheit or Celsius

Amplim Labs Thermometer

Amplim thermometer

Medical use: Get professional accuracy within 0.2 degrees Fahrenheit with this digital thermometer from Amplim Labs. This safe and accurate thermometer features last reading memory recall and automatic shut-off.

A safe alternative to glass thermometers. Clinically accurate. Memory recalls the last reading. Waterproof. The Amplim Digital Thermometer makes temperature taking faster and easier than using glass thermometers. Mercury-free.

• Amplim Thermometer specifications:
  • Safe for all: Our clinically proven accurate professional thermometers designed for detecting adult and baby fever at home, clinic, physician’s office, school, daycare, and work.
  • This top-rated digital forehead touchless/no-touch thermometer is a must-have for adult medical cabinet and newborn/ baby room, children gift basket checklist.
  • The instant-read fast thermometer is ideal for doctors, nurses, and healthcare professionals working with adults, toddlers, infants, babies, and children.

Braun medical thermometer

Braun thermoscan 5

Medical use: Braun ThermoScan 5 is fast, gentle, easy, and accurate, making it great for checking for fevers in infants and kids, and the reason Braun ear thermometers are used in more pediatrician’s offices than other children’s thermometers

Digital ear Thermometer: Braun’s innovative pre-warmed tip on the ThermoScan 5 ensures accurate temperature readings for infants and kids, unlike other ear thermometers where the cool tip of the thermometer in the ear may result in lower temperatures.

• Braun Thermometer specifications:
  • The most used thermometers by pediatricians: Your family’s health is important to you and Braun makes digital thermometers you can rely on.
  • Reliable and accurate thermometers: Braun knows that the most accurate thermometer readings are important to parents.
  • Digital thermometers for kids and adults: With innovative designs and easy to use controls, Braun child thermometers are great for adults, too.

Exergen medical thermometers

Exergen temporal scanner TaT-5000

Medical use: Ensuring superior functionality in the most demanding of hospital environments, the TAT-5000 easily stands up to the heavy-duty demands of a high-performance hospital workplace, including intensive care units and emergency departments, and all inpatient units.

Depending on patient care requirements, this model allows the choice of using disposable covers, or cleaning between patients with a disinfectant wipe, providing the means for significant cost savings by eliminating or substantially reducing probe cover usage. This revolutionary feature provides payback for full hospital installation in less than one year.

• Exergen Thermometer specifications:
  • The TAT-5000 is backed by a Lifetime Warranty.
  • Fast, safe, and comfortable for the patient
  • Fast, easy, and convenient for the clinician
  • Industrial-duty construction: Lifetime Warranty

Fluke digital thermometer

Fluke infrared thermometer 566

General use: The Fluke 566-Ex Intrinsically Safe Infrared Thermometer is certified by major rating bodies. Whether you work in chemical, oil, and gas, or pharmaceutical environments, the 566-Ex allows you to carry the most trusted name in test tools into most Ex-rated areas around the globe.

The simple, three-button on-screen menu interface is quick to use and makes even complex measurements easy. It takes just a few pushes of a button to adjust emissivity, record data, or turn on and off alarms.

Amplim thermometer

Amplim Thermometer

General Use: With a simple one-button operation, this lightweight and durable instrument allow accurate, non-contact surface temperature measurements from 50°F to 104°F at a safe distance.

Single-point laser sighting accurately ‘spots’ trouble up to 4 feet away. This thermometer is best used at a distance of fewer than 4 feet. After 4 feet, the larger sampling area does not allow for as accurate a reading

• Amplim Thermometer specifications: The forehead thermometer is backed by clinical studies and recommended by professionals. To deliver reliable results and ensure excellent performance, we apply the updated high-accuracy sensor probe and the latest smart chip. It is faster and more reliable.
  • The temporal thermometer is designed for all ages, adults, infants, and elders.
  • In addition, it is capable of taking the temperature of the room or an object.
  • ℃ and ℉ are easily switchable.
  • 1-second fast measurement with instant reading, plus mute mode, just take the temperature without waking your baby up.
  • You can read it clearly even in the dark with a large backlit LCD screen.

Digital medical thermometer market

Medical Thermometers, this indispensable iconic diagnostic device in medical practice have assumed special significance and have emerged as the most often purchased product in 2020.

The global market under this scenario is expected to accelerate and reach US$3.2 billion by the year 2027.

The sudden surge in demand is due to the rise of temperature screening and monitoring as a popular, prominent, and even mandatory practice in countries worldwide.

With fever as an obvious symptom of this health emergency, has pushed up the importance and use of case scenarios for medical thermometers.

Consumers, hospitals, healthcare response teams, airports, offices, malls, supermarkets, restaurants to cinema halls, have all stepped up the use of thermometers.

Infrared thermometers are widely preferred for screening in large public spaces given their non-contact benefit.

As community spread begins in most countries worldwide, over-the-counter (OTC) sales of digital thermometers in the consumer market are rising as well informed and aware citizens resort to self-screening and monitoring.

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An easy way to calibrate your thermometer: Now more than ever it’s important to learn how to calibrate a thermometer. Since we’re not all so lucky to own the world’s best and most accurate thermometer—which, btw, you should think about treating yourself to one—you’re going to have to learn how to test and adjust your thermometer.

A properly calibrated thermometer is key for achieving both safety and quality. The use of a properly calibrated thermometer is also key to determining if products are cooked to your preferred degree of doneness.

What is calibration of thermometer?

What is Calibrating Your Thermometer? Just like watches can run slow or fast, thermometers are subject to inaccuracies with use.

Thermometer accuracy can be affected by extreme temperature changes, or by being dropped or roughly handled. And if you’re using your thermometer frequently, you may want to check it monthly just to make sure it’s performing at its best. Luckily, you can test the accuracy of your thermometer and, in most cases, calibrate it to read accurately again.

How do you calibrate a thermometer?

Now more than ever it’s important to learn how to calibrate a thermometer. It’s the height of the pandemic, after all, and you’re going to need to check the temperature of all those patients you’re treating. Since we’re not all so lucky to own the world’s best and most accurate thermometer—which, btw, you should think about treating yourself to one—you’re going to have to learn how to test and adjust your thermometer so you are ready when needed. Here’s how:

How Do You Calibrate the Thermometer? You’ll want to check the package instructions of your device for exact instructions for calibrating your thermometer.

Many thermometers have a nut under their temperature dial that allows them to be adjusted, while most digital models have a reset button.

In rare cases, thermometers can’t be calibrated. Even if your thermometer can’t be calibrated, you can—and should—use these methods to check its accuracy and ensure that you’re getting a proper temperature read.

In this case, you can note the degree of inaccuracy and adjust your temperature accordingly. Or, in seeing that your thermometer is inaccurate, you could buy a new one.

There are two methods for testing the accuracy of your thermometer and calibrating accordingly: You can calibrate it in extremely high temperatures or using extremely cold temperatures.

Ice water method for thermometer calibration

The Ice-Water Method: An easy way to calibrate your thermometer is to put it in ice water and adjusting it to read.

• Fill a glass with ice and then fill it with cold tap water.
• Stir the ice water and let it sit for 2 minutes.
• Place your thermometer in the ice water, making sure to stick the probe at least 2 inches into the mixture, but not to touch the sides or the bottom of the glass.
• Stir the ice water with the probe to even out the temperature of the water and prevent the probe from resting against an ice cube.
• Wait at least 30 seconds for the thermometer to read the temperature.
• The temperature on your thermometer should read 32°F or 0°C. If it does not, adjust the nut on the thermometer, turning the head until the needle lands on 32°F (or use the reset button as instructed).

Thermometers calibrated in boiling water

An easy way to calibrate your thermometer is to put it in ice water and adjusting it to read

The Boiling-Water Method:

• Bring water to a rolling boil in a deep saucepan.
• Place the stem of the thermometer in the boiling water.
• Again, make sure that it’s submerged at least 2 inches and wait at least 30 seconds.
• Your thermometer should read 212°F or 100°C.
• If it doesn’t, keeping the thermometer in the water, turn the adjusting knob until the needle reaches the 212°F mark.

An easy way to calibrate your thermometer

Calibration and Adjustment: If the temperature retrieved during testing is inaccurate, consider the following adjustments.

• Dial Thermometers
  • If you are using a dial thermometer and it is inaccurate or deviates from 32°F, turn the thermometer over and adjust the gauge by twisting the nut using pliers.
  • Calibrate the thermometer again to ensure its accuracy prior to use.
• Digital Thermometers
  • Digital thermometers can be more challenging because there are no adjustments that can be made.
  • However, the inaccuracy can be added or subtracted to the final desired cooking temperature and the thermometer should be checked regularly.
  • For a video demonstration of thermometer calibration, view How to Calibrate a Meat Thermometer courtesy of the North American Meat Institute.

Remember that water boils at lower temperatures in high-altitude areas. If you live in a high-altitude area, adjust your test accordingly. Use this boiling point calculator as a guide.

At the end of this process, you will have a tool for measuring temperature that you can absolutely trust. And this accuracy isn’t just useful for backyard grilling or searing steaks on your cast-iron skillet.

Why is it important to calibrate a thermometer?

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-Thermometer Calibration Guide
-Temperature sensor calibration procedure
-Thermometers Calibration Procedure:

Calibrating your thermometer is quick and easy. Many analog and digital thermometers allow you to offset the temperature to adjust for the calibrated value. However, if your thermometer doesn’t offer an offset function, a piece of blue tape with the delta will work just fine.

The product type or the environment to be monitored will influence the selection of the most effective temperature monitoring instrument to use.

Thermometers calibration procedure

The thermodynamics of thermocouple temperature measurement is much different from bi-metal coil thermometers. A thermocouple measures the voltage potential difference between two dissimilar metals having different thermal conductivity, joined at one junction.

Thermocouple Thermometer

When heated, each metal releases an electrical current different from the other. The temperature reading is a function of the junction between the two metals, the composition of the metals, and the voltmeter measuring the current. Although calibration is possible there are many other facets to consider. There are electrical components in the digital display and the probe must be in good mechanical condition.

Consider using a commercial calibration service provided by the thermocouple manufacturer or from a NIST calibration laboratory. Voltage resolution, speed, and accuracy of the measurement and temperature range determine which thermocouple probe to use. Voltage resolution affects the thermocouple’s ability to detect small changes in temperature.

A common thermocouple type is “R,” which is a combination of platinum/13% rhodium adjacent to platinum having a temperature range from 0°C to 1000°C (32°F to 1832°F) that is accurate to within 0.5°C (0.5°F).

The characteristics of other standard probes are listed in Table 1. Any of the thermocouple types listed in Table 1 can be used for temperature measurement in meat and food processing environments. The most important consideration when choosing a thermocouple is selecting the appropriate probe or stainless steel sheath covering the thermocouple wire. For example, there are hypodermic probes, immersion probes, and penetrating probes, each used for a specific type of food (Table 2).

The cost of a thermocouple thermometer depends on the probe and the electronic component reading the voltage measurement.

Calibration procedure for thermocouple

Thermocouple thermometer calibration method:

The calibration methods used for bi-metal coil thermometers can be used for thermocouple thermometers. Some electronic units include a calibration mode, which does an internal circuitry calibration.

However, a thermocouple thermometer must be checked with external temperatures to ensure proper reading within a specified temperature range. As with any electronic equipment, check with the manufacturer for the proper method to calibrate the instrument.

Thermometers calibration procedure:

• Advantages of thermocouple thermometers
  • Wide variety probes available over a wide temperature range
  • Inexpensive
  • The temperature sensed as the tip of the probe
• Disadvantages of thermocouple thermometers
  • Requires internal reference
  • Least stable and least sensitive

Thermistor calibration method

Thermistors are fragile and can lose calibration at extremely high temperatures. Because of the nature of the component metals, thermistors are not easy to calibrate. These instruments may have an internal calibration setting similar to a thermocouple thermometer.

Using the method described for bi-metal coil thermometers will indicate if the instrument is operating within a specified temperature. Check with the manufacturer for proper calibration methodology for thermistors. (Thermometers calibration procedure)

• Advantages of thermistor thermometers
  • Highly sensitive
  • Small, thin probe available
  • Responds quickly to small temperature changes
  • Tip of the probe senses temperature
• Disadvantages of thermistor thermometers
  • Fragile
  • Limited to a few hundred-degree temperature range
  • Errors due to self-heating

Thermistor Thermometer

A thermistor is a generic term for “thermally sensitive resistors.” The keyword in this phrase is sensitive. Thermistor thermometers are the most sensitive temperature measuring devices, able to detect small changes in temperature.

Transitional metal oxides are semi-conductive materials used in thermistors. Manganese and nickel, or manganese, nickel, and cobalt are the most common component metals. Thermistors can be manufactured to fit any need and can be as small as 0.07 mm in diameter.

Thermistors can be used over a wide range of temperatures without affecting accuracy.

Non-product Contact Thermometers

Thermometers used to monitor room temperature, cooler and refrigerator temperatures are essential in maintaining high-quality products.

Depending on the HACCP plan, storage room temperature may be a critical control point for the uncooked refrigerated products. Environmental conditions, especially relative humidity affect heat transfer in large coolers. This is an important consideration during the summer months. Therefore, thermometers used to monitor room temperature must be routinely checked for calibration.

Resistance Temperature Detector

A resistance temperature detector (RTD) is a thin platinum wire wrapped around a glass or ceramic rod.

Platinum wire coils can also be embedded in a ceramic matrix. A protective coating of glass or ceramic completely houses the detector. The accuracy of temperature readings for an RTD should be compared to a NIST reference thermometer at least monthly depending on use in the facility and type of device. The RTD device is stable and accurate, however, it is fragile and not easy to calibrate. Once an RTD falters it is best to replace it. Remember to keep current records of all readings when taken and note temperature differential.

• Advantages of RTD
  • Stable
  • Accurate
• Disadvantages of RTD
  • Expensive
  • Self-heating
  • Difficult to calibrate

Thermometer calibration guide

Infrared Thermometer

An infrared (IR) thermometer is a device that collects radiant infrared energy emitted from an object. The detector converts the energy signal to a temperature reading. Most IR thermometers respond within 0.5 seconds and have 100 feet (30.5 m) maximum measuring distance, depending on the environmental conditions. The ability of an object to release or absorb energy is called emissivity.

IR thermometers are affected by an emissivity, which is complicated by shiny surfaces. Most IR units can be adjusted for emissivity by comparing the IR thermometer surface temperature of an object to a reference thermometer temperature reading of the same surface. The IR thermometer can then be adjusted to the reference temperature.

• Advantages of IR thermometers
  • Fast, accurate
  • Surface temperature measurement
  • Non-destructive, non-contact measurement
• Disadvantages of IR thermometers
  • Surface emissivity affects accuracy
  • Environmental conditions, such as relative humidity affect the accuracy

IR thermometer calibration method

IR thermometers are calibrated using a “Blackbody,” which emits a given amount of energy at a given temperature. A blackbody calibration instrument is expensive. However, most manufacturers of NIST IR thermometers provide a calibration service for a nominal fee for yearly calibration and certification.

Smokehouse thermistor probe

Smokehouse Temperature Recording Device – Batch or continuous ovens (smokehouse) use either thermocouples or RTD to monitor oven temperature during thermal processing.

The oven temperature must be continuously recorded by a chart recorder. Several electrical components involved in this process must be checked weekly and calibrated monthly by a certified technician or by the equipment manufacturer service technician. The accuracy of the probes can be checked by placing them into 140° to 180°F (60 to 82°C) hot water and comparing the temperature reading to a certified NIST reference thermometer. Record keeping is essential to track trends and any possible drift in temperature measurement.

Record Keeping

Record keeping is an essential component of any calibration program. To simplify record keeping, each thermometer should be marked with a permanent identification number or code.

At a minimum, the following information should be included in a calibration record: thermometer identification, date, time, intended use (hot/cold product or process), temperature reading difference from reference, and initials of person testing equipment.

Table 3 illustrates the use of a thermometer calibration log while a blank form is provided in Table 4. A thermometer should be replaced when a temperature difference or drift is consistently greater than ±2°F (±0.5°C). When a thermometer is replaced, a note should be made on the log and a new label assigned to the replacement thermometer.

How to calibrate a thermometer?

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NIST thermometer calibration: Temperature is a critical measurement for ensuring the safety and quality of many food products. There are a variety of commercial temperature monitoring devices available.

Whether monitoring temperatures at receiving, throughout production or final product storage and distribution, thermometer calibration is essential. The validation, verification reassessment section of the Hazard Analysis and Critical Control Point, system stated in the Code of Federal Regulations, specifies that instruments used for monitoring critical control points must be calibrated.

NIST certified thermometer

The food industry is keenly aware of the critical nature of processing temperature requirements. Instrument calibration is not only a food safety issue but also an economic consideration since the accuracy of temperature monitoring devices also affects product yields.

The National Institute of Standards and Technology (NIST) is an agency within the U. S. Department of Commerce which provides certification and calibration for thermometers and other precision instruments. When purchasing a thermometer check for the “NIST” label.

The NIST label indicates a certified instrument that will maintain accuracy within specified limits, for at least one year.

Each year, a NIST thermometer must be recertified to assure accuracy. This is a service usually provided by the manufacturer of the thermometer or a NIST calibration laboratory.

Calibrated thermometer with certificate of traceability

Calibration is the process of standardizing a temperature monitoring instrument to ensure that it will measure within a specific temperature range in which the instrument is designed to operate. The accuracy of a thermometer is its ability to measure temperature correctly without error.

A thermometer must be within ±2°F (±0.5°C) of the actual temperature to be considered an accurate device. A thermometer’s ability to detect subtle changes in temperature is its sensitivity. For example, a bi-metal coil thermometer can detect a 1.0-degree temperature change, while a thermistor may detect a 0.1-degree temperature change.

It is recommended that process or product temperature monitoring equipment be calibrated daily, before use. New equipment must be calibrated upon receipt and before putting it into service.

Also, thermometers that have been dropped on the floor or used frequently must be calibrated more often. Depending on the instrument and intended temperature use range, an ice water method and boiling water method, when used properly, are effective calibration methods.

Thermometer calibration equipment

Another technique is to use sophisticated calibration equipment available from manufacturers. These units are designed to calibrate several thermometers at one time within a specific temperature range. Many of these units are able to interface with a computer to assist with record keeping. The calibration method used at your facility depends on the temperature monitoring instrument, monitoring frequency, and intended use, and whether for a product or environmental monitoring.

Other acceptable methods may also be used to calibrate temperature monitoring instruments.

Thermometer calibration methods

Calibration methods are presented for the following temperature monitoring instruments: bi-metal coil thermometer, thermocouple thermometer, and thermistor thermometer. Calibration of non-product contact thermometers such as Resistance Temperature Detector (RTD), oven temperature recording devices, and infrared thermometers are also described. A major consideration when using any thermometer is the consistency of the product and temperature distribution throughout the product.

For instance, to measure the internal temperature of a hamburger patty 1⁄8 inch (3 mm) thick would require using an instrument having a thin probe that can detect temperature quickly and accurately. Measuring the internal temperature of a bone-in ham could be done adequately using a thick probe having a 2- to 3-inch (5.1 to 7.6 cm) temperature sensing region. The product type or the environment to be monitored will influence the selection of the most effective temperature monitoring instrument to use.

Reference Thermometers

Laboratory and industry supply catalogs market NIST reference thermometers. Local county extension agents or high school science teachers may have these catalogs. A temperature monitoring device such as a mercury-in-glass thermometer or a thermistor can be used as a reference thermometer as long as the device is NIST certified and the annual calibration and certification are maintained through a NIST laboratory.

Bi-metal Coil Thermometer

Common types of bi-metal coil thermometers are dial and instant-read digital thermometers. Contained within the stem of the thermometer is a coil made of two different metals bonded together to a temperature indicator. This type of thermometer detects temperatures from the tip of the stem to a point 2 to 2 1⁄2 inches (5.1 to 6.4 cm) above the tip. An indentation in the stem indicates the area of the stem that is the temperature sensing region.

The temperature indicated on the dial is an average of temperatures along this region. These thermometers must be inserted 2 to 3 inches (5.1 to 7.6 cm) into the geometric center of a product.

Extreme fluctuation in temperature along the sensing region can affect the extension of the bi-metal coil, which affects thermometer accuracy. Bi-metal thermometers are sensitive to physical stress such as torque on the stem, or shock from dropping on the floor. These stresses can affect the tension of the bimetal coil, which necessitates calibration of the thermometer before reuse.

Calibration of thermometer procedure

Bi-metal coil thermometer calibration method

Calibration for use in hot processes and products (boiling water method):

The items needed for calibrating thermometers used in hot processes are:
• One pint (500 ml) PyrexTM or heat tolerant container
• Distilled water
• Heat source such as a hot plate
• NIST reference thermometer

Once these supplies are assembled, the following steps are used to calibrate bi-metal coil thermometers for use in hot processes.

Thermometer calibration procedure

1. Heat distilled water to a specific reference temperature. This reference temperature can be 212°F (100°C)—described as a rolling boil at sea level altitude. The boiling point of water changes with altitude. To find the correct boiling point for your area, refer to Figure 1, Boiling point of water with relationship to altitude. An alternative reference temperature for example is the target end temperature of a product.
   Specifically, if the intended use of the thermometer is to measure the final internal temperature of a cooked uncured turkey roll at the end of thermal processing, then a target temperature of 160°F (71°C) should be used for the reference temperature.
2. Once the distilled water has reached the reference temperature, place the thermometer to be calibrated in the hot water bath. Immerse the stem to a minimum depth of 2 1⁄2 inches (6.4 cm). Place the NIST reference thermometer in the water bath at the same time, to the same depth, as the bimetal coil thermometer. Make sure that neither thermometer comes in direct contact with the bottom of the heated container or each other.
3. After one minute, compare the bi-metal coil thermometer reading to the NIST reference thermometer. Record the readings of the two instruments on a record-keeping form such as a thermometer calibration log.

Thermometer calibration guide

4. Correct the indicator needle of the bi-metal coil thermometer. Adjust the spring on the coil by turning the hex nut directly behind the faceplate of the thermometer. Digital instant-read thermometers may have a calibration button to adjust the temperature reading. If the thermometer cannot be physically calibrated and the accuracy of the unit is more than ±2°F (±0.5°C) then the unit should not be used. Contact the thermometer manufacturer for further instructions.
5. Recheck the temperature reading on the bimetal coil thermometer after making any adjustments. This is accomplished by repeating steps 1 through 3. The calibration adjustment should be noted in the thermometer calibration log.
6. Once a bi-metal coil thermometer has been calibrated for high-temperature use, label the thermometer for use in this temperature range. This can be done by electroplating or etching the thermometer on the back of the faceplate with a number or letter indicating the temperature range of its intended use.

Ice point method

Thermometer calibration for use in cold process and products (ice water method)

An easy way to calibrate your thermometer is to put it in ice water and adjusting it to read

A similar calibration procedure can be used for thermometers intended to be used in cold processes and products.

Materials necessary to calibrate a thermometer for cold uses are:
• Sturdy 1 pint (500 ml) container,
• Distilled water
• Crushed ice
• NIST reference thermometer

The same NIST reference thermometer used for high temperature calibration can be used for low-temperature calibration as long as the thermometer is allowed to equilibrate to room temperature before use.
To calibrate a thermometer for low-temperature monitoring, follow these steps:

1. Place crushed ice in a beaker or container, add just enough distilled water to make a uniform slush ice medium to facilitate even contact between thermometers and the slush ice bath.
2. Place the NIST reference thermometer in the ice water bath. It is important to keep the tip of the thermometer immersed a minimum of 2 1⁄2 inches (6.4 cm) without touching the bottom of the container.
3. The NIST reference thermometer should read 32°F (0°C) when placed in the slush ice bath. If the temperature is above 32°F (0°C), add more crushed ice to the beaker. If the reference thermometer is not equilibrating to 32°F (0°C) slush ice bath, start over with a clean beaker of crushed ice and distilled water. If this is still not working, check with the manufacturer of the NIST reference thermometer.
4. Place the bi-metal coil thermometer in the ice water bath for at least one minute by immersing it to a minimum depth of 2 1⁄2 inches (6.4 cm).
   • Be sure the tip does not touch the bottom of the container.
   • Compare the reading of the bi-metal coil thermometer to the NIST reference thermometer.
   • Adjust and recheck the bimetal coil thermometer as described for the boiling point method.
   • If the thermometer cannot be physically calibrated and the accuracy of the unit is more than ±2°F (±0.5°C), then the thermometer should not be used. Contact the thermometer manufacturer for further instructions.
   • Note calibration adjustment in the thermometer calibration log and label the thermometer for use in low-temperature ranges.
   • This can be done by electroplating or etching the thermometer on the back of the faceplate with a number or letter indicating the temperature range of its intended use.

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