| Wireless thermometers are not a new idea, by | | | | mercury) sits in a small bulb at the bottom of a |
| any stretch of the imagination. In fact, the vast | | | | long narrow tube. As temperatures rise, the |
| majority of thermometers do not use an external | | | | mercury expands, forcing its way up the tube. |
| wire at all. Even today's most advanced models | | | | Because this happens at a predictable rate, the |
| rarely rely on information being relayed through a | | | | tube can be set against a backdrop with markings |
| hard-wired system. Since this is the case, this | | | | that indicate the temperature at various stages |
| article will focus on the differing types of available | | | | of the rising mercury. These thermometers have |
| thermometers. | | | | been used for centuries. |
| One of the earliest forms of the thermometer | | | | There are many high-tech wireless thermometers |
| was made centuries before the invention of | | | | available today as well. An infrared thermometer, |
| electricity, making it one of the original wireless | | | | for instance, is a small hand-held unit that is |
| thermometers. These units use glass bubbles | | | | commonly used in a variety of industries. These |
| containing varying liquids that are sealed inside a | | | | thermometers work by picking up the infrared |
| glass tube full of water. As the temperature of | | | | energy given off by an object and focusing that |
| the water inside the tube changes, it forces the | | | | energy on a sensor that is determines the |
| glass bubbles to move up or down. Each bubble | | | | temperature. They work because everything |
| has an attached number that indicates the | | | | gives off infrared energy, provided that the |
| temperature that makes it sink to the bottom of | | | | object has not cooled below absolute zero. |
| the glass tube. As each bubble sinks, it indicates | | | | Because the amount of energy given off can be |
| the general temperature of the surrounding air. | | | | directly correlated to its temperature, these |
| Bulb thermometers are among the most common | | | | thermometers are very accurate. They are |
| wireless thermometers. These units use the | | | | commonly used in manufacturing plants and by |
| principle that liquid will contract or expand | | | | maintenance workers in many different industrial |
| depending on the temperature. The liquid | | | | sectors. |
| contained inside these thermometers (usually | | | | |