Which sensors are priced close to float switches?

- Feb 23, 2020-

The price of infrared level sensor and the capacitive water level sensor are relatively close to the float water level sensor, and both are relatively inexpensive sensors. These two sensors are superior to the float level sensor in terms of reliability and accuracy, as can be seen in the working principle and many user evaluations.


The Water float switch usually has floating ball stuck and inaccurate after using for a period of time. The reason lies in its working principle and structural design. The float level sensor uses the water level to rise and fall to drive the float. The float rises and falls to drive the reed switch on and off. According to the on / off of the reed switch, the power is turned on or off. The water float switch is a mechanical product, so its reliability and accuracy are also poor. In addition to the floating ball being easily stuck and unable to operate, the internal structure of the float level sensor has a ring magnet, which is easy to adsorb impurities in the water to form scale. The scale will cause the floating ball to increase weight and affect its accuracy. In addition, the water float switch has the disadvantages of large volume, loose and complex structure, and inconvenient cleaning.


The infrared level sensor uses the principle of optical reflection to detect the liquid level. There will be an infrared transmitting tube and a receiving tube inside the level sensor. The transmitting tube will emit light, and the light will be reflected back to the receiving tube through the light cone on the top of the sensor. When the sensor head is submerged in water, the receiving tube will receive some or no light. At this time, the sensor will give a signal to determine that there is water. When the sensor head is not in contact with water, the receiving tube will receive all the light, and the sensor will give a signal to determine that it is waterless.


The infrared level sensor has the characteristics of small size, small space occupation and convenient installation. Compared with the float water level sensor, it is easy to use, and there is no problem of bad floating ball jamming. The photoelectric water level sensor is extremely reliable and maintenance-free, which is not affected by external factors such as temperature, pressure, magnetism, liquid color, and corrosiveness, and has a wide range of applications. The problems of scale, air bubbles, and water droplets hanging on the wall can be handled by software, and the float level sensor is not a good solution due to the structure. And only a small part of the area is in contact with liquid, and there is a separate non-contact structure of the photoelectric water level sensor, so it is more hygienic and meets food hygiene standards (provided that the sensor head material is food-grade).


The biggest feature of the capacitive water level sensor is non-contact detection, which is usually attached to the outer wall of the water tank to detect the water level. Because the capacitive water level sensor does not contact the liquid, the corrosive liquid will not affect the sensor operation. The is type level sensor can be used to detect drinking food liquids in equipment such as coffee machines and water dispensers. Capacitive water level sensors have better reliability and accuracy than float water level sensors, but not as good as photoelectric water level sensors. The capacitive water level sensor is very convenient to install and can be directly attached to the outer wall of the water tank. The installation process is relatively simple, and the float water level sensor installation process is more complicated.