Dial thermometers

What is a dial thermometer?

The functionality is dependent upon the type of the thermometer. The WIKA product portfolio includes bimetal thermometers, gas-actuated thermometers, expansion thermometers, machine glass thermometers and also thermomanometers.

What is the difference between bimetal and gas-actuated thermometers?

With bimetal thermometers the temperature measurement is achieved via a mechanical deformation which transmits the movement, via a pointer shaft, to the pointer of the thermometer. With gas-actuated thermometers, on the other hand, the entire measuring system is filled with an inert gas under pressure. The measured temperature is transmitted via a capillary.

What is the most suitable dial thermometer for my application?

The following criteria are suitable for selecting the right dial thermometers for your process:

• Response time
  When it comes to speed, you will get the measuring result faster with a gas-actuated thermometer than with a bimetal thermometer. A gas-actuated thermometer, for a temperature measurement from 10 °C to 90 °C, indicates the end value after about 30 seconds. Around 60 seconds quicker than a bimetal thermometer. It should be noted that thermowells can significantly affect the response time of thermometers. How seriously depends on both the wall thickness and the type of material of the thermowell.
• Process temperature
  Usually, for scale ranges from -70 °C up to +600 °C, bimetal thermometers are used. If these are filled with liquid to protect them from high shock and vibration loads, the maximum temperature is reduced to +250 °C. Gas-actuated thermometers, on the other hand, are designed for process temperatures from -200 °C up to +700 °C. However, these are influenced by the ambient temperature, which is why the thermometer must be dimensioned accordingly for accurate measuring results.
• Remote capillary
  To measure the temperature in places that are difficult to access or far away, only gas-actuated thermometers can be used. WIKA guarantees accuracy class 1 for the corresponding measuring instrument for a capillary length of up to 60 m.

Where are dial thermometers used?

The extensive product range of WIKA dial thermometers covers the widest variety of applications. Both bimetal thermometers and gas-actuated thermometers reliably measure temperature in the fields of heating, ventilation and air-conditioning technology, machine building and plant construction, in vessel construction and equipment manufacturing, for food and beverages, oil and gas, the chemical and petrochemical industry, power generation and water/wastewater industry, and also in the food industry and sanitary applications.

What is an expansion thermometer?

WIKA expansion thermometers can be used universally in the fields of refrigeration and air-conditioning, in machine building or in the food and beverage industry. Thermometers of this type can be installed almost anywhere and, in the version with a remote capillary, are also suitable for measurement over long distances.

What is a thermomanometer?

Thermomanometers from WIKA usually consist of a combined display for pressure and temperature and are mainly used in heating systems or in combi-boilers with hot water and heating. With remote capillary, they can measure pressures up to 16 bar and also temperatures up to 150 °C over long distances, without problem.

What is a machine glass thermometer?

Machine thermometers, or also called machine glass thermometers, are particularly insensitive to vibration and are mainly used in industrial applications, such as in machine building and vessel construction, in central and large heating systems or in plant construction. Since there is no mechanical wear, glass thermometers feature particularly high accuracy and an extremely long service life.