Wireless Thermometers

The concept of wireless thermometers is not a new one. For centuries, the only instruments we had
to check the temperature were wireless ones. That is because the thermometer predates electric
current by about two to three hundred years. The thermometer itself was not a singular invention in
the vein of the light bulb or phonograph. It was more of a natural development of scientific knowledge.

The roots of the thermometer are grounded in the concept that fluids expand and contract as their
temperatures change. Both liquids and gas exhibit this characteristic, and solids do as well, albeit to a
much smaller extent. This concept was documented first by the Greeks, however the translation of that
idea into a device for gauging the temperature did not occur until the renaissance. Galileo was one
of the inventors involved in the development of the first thermometer, although he actually created a
slightly different instrument called a thermoscope.

Thermoscopes differ from thermometers because thermoscopes predate the concept of a temperature
scale. Thus they were examining something that had yet to be quantified. They could show that there
was a certain amount of heat in an area, but the concept of calling room temperature 70 degrees
Fahrenheit didn’t come about until nearly a century later. The Fahrenheit temperature scale was the
first scale devised, and it was named after its inventor, Daniel Gabriel Fahrenheit. With the unveiling
of his scale of temperature, which was derived from the freezing and boiling points of water, the
thermoscope now had a standard scale of measurement to work off of, much like yard sticks. With this
change they became thermometers, the difference hinging on the idea of a scope as investigating but
not quantifying a phenomenon, whereas a meter measured exact quantities of a known phenomenon.

While the thermometer had officially been invented electricity had not. This meant that all of them
were still wireless thermometers, since electricity didn’t receive serious investigation until nearly
two centuries later. Early versions used alcoholic solutions of different densities to signify different
temperatures. The solutions would be suspended within small glass globes, which would then be
placed inside a cylinder filled with water. At certain temperatures, different globes would float to the
measurement line, signifying what the current temperature was. Those globes above the line were
lower temperatures, the globes below the line were higher temperatures.

This complex method of measuring temperature was later replaced by the much simpler process of
mercury trapped in a vacuum tube. It was found that mercury expanded at a constant rate through the
normal range of terrestrial temperatures, so a series of markings next to the cylinder could easily show
the current temperature by comparing the mercury level to the markings. This elegant solution to telling
the temperature was still a wireless thermometer, though not of the sort we have today.

As temperature became a standard measurement, the Celsius scale was introduced as the metric
temperature sale. Later on, the Kelvin scale was introduced, to account for temperature ranges outside
our Earth, from the hot temperature of the sun to the cold of deep space. During this time the ability

to measure temperature found ever greater uses. You could tell the temperature outside, certainly. But
you could also tell if a person was feverish, and if so exactly how severe the fever was. You could check
t he internal temperature of cooking meat. This was where wiring first showed itself in thermometers. A
needle would be inserted into the meat, which was attached to a digital display via insulated wiring. This
way you could check the temperature of the turkey without opening the oven.

With the advent of wireless technology, it was only a matter of time before wireless thermometers
improved on the existing models of the day. Today you can get those same digital displays that can
measure the temperature of the oven, of the room, of a sick child, or even from outside. All beamed
wirelessly from the measurement locations to the display console.