Dial thermometers moved bimetallic coils, mercury, steam or gas pressure. They are available in various forms that enable dial be used in several places. Cm. Fig. 1-29. The sensitive part of the unit may be located somewhere else. Dial can be read in a convenient location.
Bimetal thermometers have a linear dial. There are equal parts during any given set of ranges. Dial ranges are also available to meet higher temperature measurement needs. Ranges of up to 1000F (537.8C). In the four selected ranges, a set of giving Fahrenheit and Celsius readings. Bimetal thermometers economic. There is no need for the treated movement or a reducer. Thermosensitive bimetallic element connected directly with the mouse pointer. This type of thermometry well suited for measuring the surface temperature. The dome is mounted thermal patrons to actually react on the surface of the skin temperature of the compressor. These thermometers used where direct readings should be taken, for example, on:
The simplest type of scale thermometer barrel.
Stem is inserted into the liquid. With stem immersed in 2. in liquids and 4 century in gases, this thermometer gives a fairly accurate reading.
- Air ducts
- Heat exchangers
- Laboratory temperature of the bath
Although dial thermometers have many uses, there are some restrictions. They are not as universally applicable as a simple glass thermometer. When ordering dial thermometer, specify the length of the rod, range scale, and the environment in which it will be used. One of the advantages of bimetallic thermometry, that the thermometer can be applied directly to the surface. It can be designed to take the temperature of the pipes in the range from 0.5 to 2 century
In operation, the bimetallic spiral closely associated with the hot surface of what can be measured. Thermometer firmly two permanent magnets. One manufacturer claims that their type of thermometer reaches stability during 3 minutes Precision is called " plus " or " minus 2% in operating ranges.
A simple and inexpensive type of bimetal thermometer scribes temperature trip on the load of food in the path. It can also be used to check the temperature in a controlled industrial areas. Replacement diagram gives a permanent account fluctuations in temperature during the test period. Dual layer discs are also used in the control devices. For example, thermal overload, the sensors engines and other appliances, the use of bimetallic elements. Other examples will be discussed later...