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Platinum was proposed by Sir William Siemens as an element for a resistance temperature detector at the Bakerian lecture in 1871: [2] it is a noble metal and has the most stable resistance–temperature relationship over the largest temperature range.
The Callendar–Van Dusen equation is an equation that describes the relationship between resistance (R) and temperature (T) of platinum resistance thermometers (RTD). As commonly used for commercial applications of RTD thermometers, the relationship between resistance and temperature is given by the following equations.
Vapor pressure–temperature relationship fixed by a specified function. [10] 3 24.5561 1 Helium gas thermometer: Calibrated at three fixed points in this range and interpolated in a specified way. [11] 13.8033 1234.93 11 Platinum resistance thermometer: Resistance calibrated at various fixed points and interpolated in a specified way.
Platinum has excellent resistance to corrosion. Bulk platinum does not oxidize in air at any temperature, but it forms a thin surface film of PtO 2 that can be easily removed by heating to about 400 °C. [17] [18] The most common oxidation states of platinum are +2 and +4. The +1 and +3 oxidation states are less common, and are often stabilized ...
The more regular the lattice is, the less disturbance happens and thus the less resistance. The amount of resistance is thus mainly caused by two factors. First, it is caused by the temperature and thus amount of vibration of the crystal lattice. Higher temperatures cause bigger vibrations, which act as irregularities in the lattice.
The thermocouple temperature is limited also by other materials used. For example beryllium oxide, a popular material for high temperature applications, tends to gain conductivity with temperature; a particular configuration of sensor had the insulation resistance dropping from a megaohm at 1000 K to 200 ohms at 2200 K. At high temperatures ...
A thermistor is a semiconductor type of resistor in which the resistance is strongly dependent on temperature. The word thermistor is a portmanteau of thermal and resistor.The varying resistance with temperature allows these devices to be used as temperature sensors, or to control current as a function of temperature.
This definition also precisely related the Celsius scale to the Kelvin scale, which defines the SI base unit of thermodynamic temperature with symbol K. Absolute zero, the lowest temperature possible, is defined as being exactly 0 K and −273.15 °C. Until 19 May 2019, the temperature of the triple point of water was defined as exactly 273.16 ...