Capillary thermometers have many advantages, including the ability to take measurements in hard-to-reach places, even in the smallest pipelines. In the following entry, we explain what a capillary thermometer is, how it is constructed and tell you how to choose the right one for your application.
The capillary tube can only be connected to a gas thermometer, it is not present in bimetallic thermometers.
The elements of a capillary thermometer are:
With a dial thermometer with a capillary, it is possible to measure temperatures in inaccessible points. Even the smallest pipes can be reached by means of the contact bulb. Another advantage is the bridging of larger distances, so that this type of thermometer can be centrally integrated into a control cabinet, switchboard or control panel.
A capillary is a very thin glass tube, inside of which a synthetic liquid flows. Under the influence of temperature changes its volume, which causes the pointer to bend on the background of the thermometer's dial with the temperature scale.
Temperature measurement is based on the phenomenon of expansion of the liquid placed in the capillary tube. The temperature is read by a sensor, placed at the end of the capillar
The capillary thermostat is used to control electrical equipment, such as heaters or blowers, in temperature control systems. Thermostats are used to maintain the temperature at a constant level or to monitor it in order to prevent overheating of components.
The measuring principle is based on the expansion of fluids under the influence of heat. The fluid is enclosed in a metal tube and expands or contracts when the temperature changes. The change in temperature of the fluid causes a diaphragm to move, which makes contact with the snap switch and opens or closes the circuit. This results in a very accurate measurement.
The sensors in the thermostat are connected via a capillary. Based on the set temperature, the sensor closes when the temperature rises and opens when the temperature falls.
