The most popular ones include the Bimetal Thermometer - Jun Ying Instruments
Bimetal thermometers are made up with bimetallic strips joining two different metallic strips that have different thermal expansion co-efficient. This is a mechanical temperature measuring instrument that can sense temperature and transform it into mechanical displacement. This mechanical action from the bimetallic strip can be used to activate a switching mechanism to get an electronic output. Commonly this is attached to a pointer that shows the reading on the measuring instrument. Two different metallic strips can be welded, bolted or riveted, so it is known as bimetallic thermometer. Two different metals would respond differently
Bimetal thermometers are designed to measure temperature in a vessel or pipelines. These can be utilized in air conditioning and equipment manufacturing industries. Thermowell can be an option along with this instrument that can be easily screwed to it. These are preferred in various applications. These are available in wide ranges of stem lengths and nominal diameter sizes that can fit the particular process requirements. These are offered in various connection designs and usually the case and stem would be made of high quality stainless steel for durability and better performance.
Thermowell is a tubular device that protects temperature sensor. It can be fitted from one end through clamps or threads provided for screwing it. This is mostly utilized in food and drugs process industry for measuring temperature of various fluids. A temperature sensor such as thermocouple or thermometer is inserted through the open end of the tube that is usually kept outside the process vessel, piping and any thermal insulation. The temperature would be transferred to the wall of thermowell and in turn transferred to the sensor.
Pressure snubber act as protecting fixture in pressure gauges that help to damp the vibration and pulsation created by fluid being measured and thus protects the pressure gauge from any breakdown.Source: http://jyinstruments1.blogspot.com/2017/09/the-most-popular-ones-include-bi