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The history and current state of temperature measuring instruments offered by Fluke

By Chuck Newcombe

April 2012

Fluke 62 MAX

Early in 1986 Fluke offered its first handheld thermometers, the models 51 (single input) and 52 (dual input). These meters measured temperature by direct contact, using either J or K type thermocouple probes. The primary target applications for these products included the monitoring of industrial processes and, perhaps even more commonly, HVAC applications.

Among the more compelling applications for these Fluke thermometers has been the testing of grill and meat patty temperatures at fast-food restaurants. This testing became routine after a major fast-food chain had an outbreak of food-borne illnesses in the early 1990s, where meat was not being cooked to a temperature high enough to kill the offending bacteria.

Fluke sells several digital contact temperature measuring tools that use thermocouple probes. The line was updated in 1999 to the four models of the Fluke 50 Series II. Improvements included the ability to use five additional thermocouple types, and the models 53-II and 54-II also have the capability to record readings internally for later download to a computer using FlukeView® Forms software.

The food service industry today

Fluke has had a continuous presence in the food service industry since that day in 1993 when the company was called upon to supply the digital thermometers to be used daily in fast-food outlets. The tests have their basis in an industry process known as hazard analysis and critical control points (HACCP). The HACCP process began in the 1960s, when NASA called for detailed information about food preparation for the foods to be used during spaceflights.

Today HACCP is used throughout the food industry and is at the heart of food handling - from the monitoring of package temperatures during shipment and storage, to the verification of correct cooking temperatures during food preparation.

And now, in addition to the Fluke 50 Series II contact thermometers, Fluke’s line of products includes the FoodPro and FoodPro Plus Infrared Food Thermometers with specific HACCP test indicators built in. The FoodPro Plus also has inputs for contact thermometer probes to be used during tests of cooking operations.

The shift to noncontact temperature measurements

Shortly after the introduction of the 50 Series II, Fluke began its move into noncontact thermometry using infrared technology. The first product offered was a digital IR thermometer. Today the products available include a wide range of IR thermometers as well as a family of IR thermal imagers with powerful innovative features. More about those later.

Meanwhile, for a quick discussion of noncontact vs contact measurements, you might want to take a look at my kitchen experiments of years past (“It’s all relative”) »

The mainstream for temperature measurements - industrial and commercial

Check out Fluke’s latest offering in the handheld IR thermometer line: the new mini IR models Fluke 62 MAX and 62 MAX+. These are the new and improved models of the basic IR thermometer introduced by Fluke more than a decade ago. They are inexpensive and easy to use, and feature the ruggedness that is a hallmark of Fluke test tools. In fact, they are IP54 (water and dust resistant) and withstand a 9.5 foot (3 meter) drop.

Now, more about Fluke thermal imaging

Utility transformers as viewed with Fluke IR-Fusion® imaging

Fluke entered the world of thermal imaging with a bang at about the time that I retired. I actually worked on one of the teams introducing the product, taking some representative industrial pictures.

One of those was of a pair of utility transformers on a pole near a local mini-mart. I decided to go out and re-create that scene on a cold morning for this column.

The big difference with today’s products is that they show a blending of IR and visible images to clearly show the relationship of the IR image to its surroundings, in this case the utility pole and wires.

What I can tell you about this installation is that the smaller transformer is clearly under greater load, servicing two phases of a three-phase service for refrigeration, while the bigger transformer furnishes the remaining three-phase and the single-phase requirements of the store, under less stress as indicated by cooler operating temperatures.

Ouch! My leg is hot

Don’t block the cooling vents on your laptop computer

A couple of days ago, while researching this story, my laptop decided to conduct some updates at the same time. I became painfully aware of this when I suddenly noted a burning sensation in my leg.

Since I had a thermal imager handy, I took this shot of the bottom of my laptop, only to discover that the case temperature was over 110°F (43°C) near the power input.

In these two examples, I had to manually focus the system to get the clearest images at a distance and then in a close-up shot.

The newest of Fluke’s family of thermal imagers

With the recently announced Ti and TiR Series imagers, Fluke has made the process of getting a good image simpler than ever. Two features caught my eye.

  • The IR-OptiFlex™ focus system automatically selects the best image over most of the focusing range, with manual ranging always available for close-ups.
  • Rugged construction, withstanding drops of up to six feet (1.8 meters)!

With the addition of video recording, an electronic compass, and the amazing and unique IR-Fusion® capability, these latest offerings by Fluke are truly cutting-edge products.