LABORATORY THERMOMETER (-10°C - 110°C)

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The temperature is normally displayed in degrees Celsius, but it can also be displayed in Fahrenheit. Celsius and Fahrenheit are two different scales for measuring temperature.

When the tip of the mercury thermometer touches the material it is measuring, the material conducts heat energy to the mercury. Thermometers are calibrated in various temperature scales that historically have relied on various reference points and thermometric substances for definition. The most common scales are the Celsius scale with the unit symbol °C (formerly called centigrade), the Fahrenheit scale (°F), and the Kelvin scale (K), the latter being used predominantly for scientific purposes. The kelvin is one of the seven base units in the International System of Units (SI). by Yoming S. Lin. PowerKIDS Press/Rosen, 2012. A historical introduction that runs the stories of Daniel Fahrenheit and Anders Celsius alongside the practical measurement of temperature. The thermodynamic temperature is said to be absolute for two reasons. One is that its formal character is independent of the properties of particular materials. The other reason is that its zero is, in a sense, absolute, in that it indicates absence of microscopic classical motion of the constituent particles of matter, so that they have a limiting specific heat of zero for zero temperature, according to the third law of thermodynamics. Nevertheless, a thermodynamic temperature does in fact have a definite numerical value that has been arbitrarily chosen by tradition and is dependent on the property of particular materials; it is simply less arbitrary than relative "degrees" scales such as Celsius and Fahrenheit. Being an absolute scale with one fixed point (zero), there is only one degree of freedom left to arbitrary choice, rather than two as in relative scales. For the Kelvin scale since May 2019, by international convention, the choice has been made to use knowledge of modes of operation of various thermometric devices, relying on microscopic kinetic theories about molecular motion. The numerical scale is settled by a conventional definition of the value of the Boltzmann constant, which relates macroscopic temperature to average microscopic kinetic energy of particles such as molecules. Its numerical value is arbitrary, and an alternate, less widely used absolute temperature scale exists called the Rankine scale, made to be aligned with the Fahrenheit scale as Kelvin is with Celsius.

A single kelvin is referred to as a unit, rather than a degree, and is equal to a single degree on the Celsius scale. The Kelvin scale is mainly used by scientists.

Cons: Vibration may be missed, prone to user error, doesn't work well for kids that won't sit stillThe main types of thermometers are new digital thermometers, including infrared thermometers, and older mercury thermometers. The thermometer calibration process described above results in what is known as a centigrade thermometer. A centigrade thermometer has 100 divisions or intervals between the normal freezing point and the normal boiling point of water. Today, the centigrade scale is known as the Celsius scale, named after the Swedish astronomer Anders Celsius who is credited with its development. The Celsius scale is the most widely accepted temperature scale used throughout the world. It is the standard unit of temperature measurement in nearly all countries, the most notable exception being the United States. Using this scale, a temperature of 28 degrees Celsius is abbreviated as 28°C. Referring to the Boltzmann constant, to the Maxwell–Boltzmann distribution, and to the Boltzmann statistical mechanical definition of entropy, as distinct from the Gibbs definition, [5] for independently moving microscopic particles, disregarding interparticle potential energy, by international agreement, a temperature scale is defined and said to be absolute because it is independent of the characteristics of particular thermometric substances and thermometer mechanisms. Apart from the absolute zero, it does not have a reference temperature. It is known as the Kelvin scale, widely used in science and technology. The kelvin (the unit name is spelled with a lower-case 'k') is the unit of temperature in the International System of Units (SI). The temperature of a body in a state of thermodynamic equilibrium is always positive relative to the absolute zero. The heat is then turned into electricity and sent to a detector, which then produces a number on the display to say what the temperature of the object is. 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 ]

perfectly safe if it's sealed inside a thermometer. However, if the glass tube of a mercury thermometer Defined according to the triple point of water (where its solid, liquid, and vapor are in equilibrium), which is 273.16 K. Mercury thermometers look like sealed glass tubes with a liquid inside and numbers marked on the side to display the temperature. The liquid is called mercury, which is perfect for measuring temperatures because it changes from a solid to liquid very easily and it is the only metal that is in liquid form at room temperature. Mercury has a high boiling point so it is suitable to measure higher temperatures. Any of various standardized numerical measures of this ability, such as the Kelvin, Fahrenheit, and Celsius scale.

Other words from thermometer

If you pay with cash or credit card in a store or online, you can request a reimbursement from your HSA/FSA account. Different plans have different requirements on what's needed for reimbursement but usually, a copy of your thermometer receipt will be enough. Place the thermometer in the center of the container and make sure that it is not touching any sides or bottom. After Fahrenheit's death in 1736, the Fahrenheit scale was recalibrated to make it slightly more accurate. The exact freezing and boiling points of plain water, minus the salt, were marked at 32 and 212 degrees Fahrenheit, respectively. Normal human body temperature was marked at 98.6.

Dr. John Vann, a pediatrician in Omaha, told Insider that only a rectal temperature offers a true outpatient reading. "Everything else is an estimate," he said. It is possible to measure the average kinetic energy of constituent microscopic particles if they are allowed to escape from the bulk of the system, through a small hole in the containing wall. The spectrum of velocities has to be measured, and the average calculated from that. It is not necessarily the case that the particles that escape and are measured have the same velocity distribution as the particles that remain in the bulk of the system, but sometimes a good sample is possible. 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).

Temperature is one of the principal quantities in the study of thermodynamics. Formerly, the magnitude of the kelvin was defined in thermodynamic terms, but nowadays, as mentioned above, it is defined in terms of kinetic theory. Basically, to perform an ice bath test, you need to prepare an ice bath with equal amounts of water and ice. The thermometer should be placed in the center of the bath, and the temperature should read at exactly 32°F. This reading indicates that the thermometer is accurate.