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Thermometer

Many of life's activities are heavily influenced by the temperature. A variety of different thermometers suitable for monitoring the body temperature are presently available. Examples of such thermometers include traditional glass and mercury thermometers, metallic probe type electronic thermometers, and thermometers that are inserted into the ear canal. Thermometers are classified into contact and non-contact types based on the method of utilization. There are various kinds of contact thermometers, such as resistance thermometers, thermocouple and liquid-in-glass thermometers. The non-contact thermometers are mainly directed to radiation thermometers. The basic mercury thermometer has been the standard for measuring body temperature for decades and is known virtually throughout the world. It consists of a hollow glass rod with a bulb of mercury at one end and a temperature scale along the glass rod. Electronic or digital thermometers have been developed to overcome the shortcomings of conventional glass and mercury clinical thermometers. Electronic thermometers have many advantages over conventional thermometers and have essentially replaced the use of conventional glass thermometers in the healthcare field. One advantage of electronic thermometers over their conventional glass counterparts is the speed at which a temperature reading can be taken. Electronic thermometers are widely used in the healthcare field for measuring a patient's body temperature. Typical electronic thermometers have the form of a probe with an elongated shaft. Electronic temperature sensors such as thermistors or other temperature sensitive elements are contained within the shaft portion. Infrared (IR) thermometers are devices which measure temperature without having physical contact with the object being measured (the "object"). The IR thermometer detects intensity of IR radiation which is naturally emanated from the object's surface. Infrared thermometers are able to determine the temperature of a body based on the intensity of the infrared radiation emitted by the body itself. It should be noted that all bodies emit a radiation proportional to their current thermal condition. The IR thermometer typically includes a housing which may have a variety of shapes depending on its application. An infrared radiation radiation thermometer includes a housing with a window admitting radiation, an internal optic system and an infrared sensor that is associated with an evaluation unit. The window admitting radiation serves to close off the interior of the housing of the radiation thermometer, thereby protecting the optic system and the sensor from contamination and destruction.

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