The water level sensor can be divided into contact type and contactless type according to the measurement method. Water level sensors are often used in water treatment, metallurgy, petroleum, chemical industry and other industries. Here are two water level sensors with different measurement methods: Contact and contactless water level sensors.
The contact water level sensors include the capacitive type, floating ball type, floater type and pressure type. In the process of water level measurement, detection sensors are in direct contact with the measured medium. In some applications, the detection sensor will produce reactants, which leads to the sensor's abnormal working. Therefore, when choosing the sensor, you need to understand the characteristics of the medium to be measured.
Contactless water level sensors mainly include radioactive isotope type, ultrasonic type, radar type, external paste type. For radioactive isotope type water level sensor, it is not suitable for occasions where large range water level measurement is needed because of its small measuring range. The ultrasonic water level sensor has a wide range, which can be used to conduct large range measurement. What's more, contactless measurement is also achieved, which is not affected by the medium. The disadvantage is that the application of ultrasonic water level sensor is restricted by medium temperature, ambient temperature, the fluctuation degree of measured water level and many other external environmental factors. These restrictive factors will seriously affect the measurement accuracy of ultrasonic water level sensor. The medium characteristics have a certain influence on the measurement range of radar water level sensor. The liquid with a small dielectric constant has a great influence on the measurement distance of the radar water level meter, which reduces its measurement range. The liquid with large dielectric constant has little effect on the measuring distance of radar water level meter, and the measuring range is enlarged. The water level sensor of external paste type is suitable for the measurement of sealed containers and inflammable and explosive dangerous media. The probe can be directly adsorbed on the bottom of the container and measurement can be finished by using the principle of sonar ranging without trepanning the container and stopping to measure.
Therefore, different liquid level sensors have different application occasions. According to the needs of field measurement, we decide to choose the contact type or contactless type, and then see which measurement principle is more suitable for current liquid level measurement.