The use of bimetallic thermometer

Field temperature measurement in industrial production is the most widely used bimetallic thermometer, this is the most widely used except pressure gauge indicating instrument at the scene. According to field use environment and the north of the type and installation method has a variety of media characteristics. The most common way of header is universal type ( In certain Angle range header can choose) This kind of thermometer, since the dial to adjust the Angle, site installation, Don't consider the direction of the header) when installing And process engineering inspection record ( Can adjust the header to facilitate observation reading) Bring great convenience. Because the process of high temperature and high pressure measured medium is the most widely used way of installing movable external thread installation, the opening through the process pipeline equipment welding bimetal mouthpiece, Connection head) And then through the threaded connections, through double metal gasket seal installation. According to the situation of site to start construction craft and the material of choice to protect casing corrosion and change the way, the most common protection casing is 316 l stainless steel material, if the site you can choose online replacement required high temperature core-pulling thermometer, can not affect plant production of replacement of bimetallic thermometer online. Bimetallic thermometer selection before installation should pay attention to the outside in addition to the above two indicators is inserted into the depth and the measuring range, basic insert depth according to the process piping or equipment size size to select, process pipeline requirement is basically a median line for process pipeline double metal mouthpiece to the flow direction of medium is mostly against the welding so when choosing insert depth than pipe diameter, if bimetal connection head exposed pipe is longer and add its length to insert depth, only the bimetallic temperature measuring part in medium near the center line of the temperature measurement accuracy is high. Measuring range according to the process of medium temperature range to choose, the most ideal situation is normal temperature indicator in the center of the dial, the measured temperature range for three times, but the reality of bimetallic thermometer is essentially multiples of 50 degrees, so when choosing when to choose to be the most close to the range of the thermometer. Bimetallic thermometer and pressure gauge compared internal structure simple, its most parts of the core is a double metal, it is at the forefront of double metal probe, double metal into a welding spiral, the other end connected with a thin hard stainless steel strips, thin in bimetal header connection, at the end of it through a buffer spring is connected to a header pointer. Temperature changes caused by the expansion rate of double metal because of different bimetallic collision in spiral double metal free end rotation drive the connecting rod ( Thin) Rotation, and finally to the buffer spring, distorting spring spring pointer to the upper connecting rod rotates, finally the rotation of the pointer indicator on the panel. It shows double metal internal structure is double metal, connecting rod, Thin) , buffer springs and a connecting rod of the pointer, bimetallic here is detecting element, connecting rod, buffer spring is transmission parts, connecting rod is pointer indicating device. Accidentally in idle bored at work in the warehouse to find a few scrap double metal removal of the play, and to try to repair, found some problems, by removing the original purchase of the double metal removal at the double metal can find and internal components can remove out, and now a lot of bimetal is through internal welding outside left inside a can out of connecting rod obligate mouth cannot be pulled out, the biggest disassembly is the header dismantled. By removing found the buffer spring on the temperature of the dial indicator plays a big role. If the buffer spring torsion different indicator on the dial of the difference is very big. So it is concluded that the bimetallic thermometer zero can by adjusting the buffer spring pre-tightening force. Bimetallic thermometer is loaded into the lower limit alarm chain function of the instrument, it is through the design in the pointer indicates two can adjust electric shock to meet with a fixed contact to achieve output contact type, although its core features complicated but still as common as the structure of the bimetallic thermometer. Bimetallic thermometer in daily use in addition to the affected by bimetallic itself characteristics of the no linear with the installation instructions to environmental factors such as anti-vibration effect in the field devices in the import and export of the pump and double metal because the vibration of the pipeline caused by buffer spring elasticity coefficient change instructions, so can only change the buffer spring or discarded directly.