Temperature is generally thought of as the relative degree of ‘hotness’ or ‘coldness’ of a specific object or material. In actuality, temperature is a measure of the average thermal energy (internal kinetic energy) of an object. Thermal energy is associated with the motion (kinetic energy) of the atoms and molecules making up the object/material. Higher temperatures correspond to higher thermal energies (faster motion of atoms and molecules), whereas colder temperatures correspond to lower thermal energies (slower motion of atoms and molecules).
Properties of materials and nearly all biological, chemical, and physical processes are temperature dependent. Temperature is also a fundamental weather variable. As a result, temperature is perhaps the most widely measured environmental variable.
Thermometers are sensors that measure temperature. Thermometers are often electronic, and are available in multiple options including thermocouples, thermistors, and platinum resistance thermometers.
The main advantages of thermistors over other electronic thermometers (thermocouples, platinum resistance thermometers) are high signal-to-noise ratio, requirement of only a single-ended channel for measurement, and low cost, while still maintaining comparable accuracy. Apogee Instruments offers three thermistor temperature sensors. Each Apogee thermistor, outputs an analog voltage (when supplied with an input voltage) that is related to thermistor resistance; resistance is directly related to temperature.
- ST-100 thermistor is weatherproof and is designed for contnuous temperature measurement in air, soil, or water.
- ST-110 thermistor is designed for continuous air temperature measurement when housed in the TS-100 Fan-aspirated Radiation Shield.
- ST-200 thermistor is a fine-wire thermistor designed for temperature measurement of delicate surfaces (e.g., leaves, fruits) and small samples.
Apogee Instruments offers two PRTs, both are designed for continuous air temperature measurement when housed in the TS-100 Fan-aspirated Radiation Shield.