DIFFERENT TEMPERATURE MEASURING DEVICES 1. Thermometer Thermometers are well-known liquid expansion devices also used for temperature measurement. Generally speaking, they come in two main classifications: the mercury type and the organic, usually red, liquid type. The distinction between the two is notable, because mercury devices have certain limitations when it comes to how they can be safely transported or shipped. 2. Thermocouples Thermocouples are voltage instruments that use a change in voltage to indicate the measurement of temperature. The thermocouple's output voltage increases with temperature, though not always linearly. The thermocouple is often enclosed in a ceramic or metal shield that shields it from exposure to various conditions. 3. Bimetallic Devices Bimetallic devices benefit from metals' tendency to expand when heated. Two metals are joined together and mechanically connected to a pointer in these thermometers. The bimetallic strip will expand more than the other side when heated. The temperature reading is also indicated when correctly geared to a pointer. 4. Silicon Diode The conductivity of the diode increases linearly in the low cryogenic areas, making them essentially linear devices. Whatever sensor you use, it probably won't be working by itself. The selection of the sensor will rely on how it will be integrated into a system because the majority of sensor options overlap in temperature range and precision. 5. Change-of-State Sensors A change in a material's condition caused by a change in temperature, such as the transition from ice to water to steam, is precisely what change-ofstate temperature sensors measure. Devices of this type might be purchased in the form of labels, pellets, crayons, or lacquers. 6. Resistive Temperature Measuring Devices Devices for measuring resistance temperature are electrical as well. They take advantage of another property of matter that changes with temperature - its resistance - as opposed to the thermocouple's use of a voltage. At OMEGA Engineering, Inc. in Stamford, Connecticut, we work with thermistors and metallic resistive temperature devices (RTDs), both of which are forms of resistive devices. 7. Infrared Sensors Non-contact sensors include infrared ones. As an illustration, if you hold a common infrared sensor up to the front of your desk without making physical contact, the sensor will radiate information about the desk's temperature, which is most likely 68°F at standard room temperature. Ice water will register slightly below zero degrees Celsius in a non-contact measurement due to evaporation, which slightly lowers the expected temperature result.
