I liked that it has a fever alarm and color temperature indication to take the guesswork out of interpreting the readings. The manual also includes a very comprehensive comparison table on how to interpret measurements based on age and method. The thermometer can also store up to 20 past readings for easy comparison. Temperature is important in all fields of natural science, including physics, chemistry, Earth science, astronomy, medicine, biology, ecology, material science, metallurgy, mechanical engineering and geography as well as most aspects of daily life. the physical properties of materials including the phase ( solid, liquid, gaseous or plasma), density, solubility, vapor pressure, electrical conductivity, hardness, wear resistance, thermal conductivity, corrosion resistance, strength Photo courtesy of National Institute of Standards and Technology Digital Collections, Gaithersburg, MD Temperature scales need two values for definition: the point chosen as zero degrees and the magnitudes of the incremental unit of temperature.

By the early 18th century as many as 35 different temperature scales had been devised. The German physicist Daniel Gabriel Fahrenheit in 1700–30 produced accurate mercury thermometers calibrated to a standard scale that ranged from 32°, the melting point of ice, to 96° for body temperature. The unit of temperature (degree) on the Fahrenheit temperature scale is 1/ 180 of the difference between the boiling (212°) and freezing points of water. The first centigrade scale (made up of 100 degrees) is attributed to the Swedish astronomer Anders Celsius, who developed it in 1742. Celsius used 0° for the boiling point of water and 100° for the melting point of snow. This was later inverted to put 0° on the cold end and 100° on the hot end, and in that form it gained widespread use. It was known simply as the centigrade scale until in 1948 the name was changed to the Celsius temperature scale. In 1848 the British physicist William Thomson (later Lord Kelvin) proposed a system that used the degree Celsius but was keyed to absolute zero (−273.15 °C); the unit of this scale is now known as the kelvin. The Rankine scale (see William Rankine) employs the Fahrenheit degree keyed to absolute zero (−459.67 °F). Measurement of the spectrum of noise-power produced by an electrical resistor can also provide accurate temperature measurement. The resistor has two terminals and is in effect a one-dimensional body. The Bose-Einstein law for this case indicates that the noise-power is directly proportional to the temperature of the resistor and to the value of its resistance and to the noise bandwidth. In a given frequency band, the noise-power has equal contributions from every frequency and is called Johnson noise. If the value of the resistance is known then the temperature can be found. [15] [16] Macroscopic thermodynamic scale [ edit ] Accurate temperature readings are essential in many industries such as research, medicine and food production. As such, it is important to correctly calibrate your thermometer. But how often should this be done? Below are four key scenarios when you need to recalibrate your thermometer. A measure of the warmth or coldness of an object or substance with reference to some standard value.This is a unique anonymous session identifier cookie set by Microsoft Application Insights software to gather statistical usage and telemetry data for apps built on the Azure cloud platform.

Chart: The Celsius temperature scale is shown in blue with the Fahrenheit scale in red alongside. Each point on the chart shows the two equivalent measurements for a certain temperature, so, for example, 20°CMany Americans think anything over 98.6 degrees Fahrenheit is a problem, but what constitutes a fever is different from person to person. It was the most accurate thermometer in my tests, reading within 0.5-1.0 degrees again and again for forehead readings and within 0.5-0.8 degrees for ear mode. It also displays the temperature within one second. This cookie is used to a profile based on user's interest and display personalized ads to the users.