pressure gas thermometer Constant volume gas thermometer Liquid crystal thermometer Liquid thermometer principle: relation between temperature and volume of a liquid (coefficient of thermal expansion). Alcohol thermometer Mercury-in-glass thermometer Pyranometer principle: solar radiation flux density relates to surface temperature (Stefan–Boltzmann law) Pyrometers principle: temperature dependence of spectral intensity of light (Planck's law), i.e. the color of the light relates to the temperature of its source, range: from about −50 °C to +4000 °C, note: measurement of thermal radiation (instead of thermal conduction, or thermal convection) means: no physical contact becomes necessary in temperature measurement (pyrometry). Also note: thermal space resolution (images) found in thermography. Resistance thermometer principle: relation between temperature and electrical resistance of metals (platinum) (electrical resistance), range: 10 to 1,000 kelvins, application in physics and industry Solid thermometer principle: relation between temperature and length of a solid (coefficient of thermal expansion). Bimetallic strip Thermistors principle: relation between temperature and electrical resistance of ceramics or polymers, range: from about 0.01 to 2,000 kelvins (−273.14 to 1,700 °C) Thermocouples principle: relation between temperature and voltage of metal junctions (Seebeck effect), range: from about −200 °C to +1350 °C Thermometer Thermopile is a set of connected thermocouples Triple point cell used for calibrating thermometers. Imaging technology Thermographic camera uses a microbolometer for detection of heat radiation. See also Temperature measurement and :Category:Thermometers. More technically related may be seen thermal analysis methods in materials science. For the ranges of temperature-values see: Orders of magnitude (temperature) Energy carried by entropy or thermal energy This includes thermal mass or temperature coefficient of energy, reaction energy, heat flow, ... Calorimeters are called passive if gauged to measure emerging energy carried by entropy, for example from chemical reactions. Calorimeters are called active or heated if they heat the sample, or reformulated: if they are gauged to fill the sample with a defined amount of entropy. Actinometer heating power of radiation. Constant-temperature calorimeter, phase change calorimeter for example an ice calorimeter or any other calorimeter observing a phase change or using a gauged phase change for heat measurement. Constant-volume calorimeter, also called bomb calorimeter Constant-pressure calorimeter, enthalpy-meter, or coffee cup calorimeter Differential Scanning Calorimeter Reaction calorimeter See also Calorimeter or Calorimetry Entropy Entropy is accessible indirectly by measurement of energy and temperature. Entropy transfer Phase change calorimeter's energy value divided by absolute temperature give the entropy exchanged. Phase changes produce no entropy and therefore offer themselves as