Capacitive level switch
The capacitive level switch detects the tiny difference in capacitance (usually in picofarads, PF) caused by the change in the liquid level. The dedicated ADA capacitance detection chip is used for signal processing (it can output various signal communication protocols, such as: IO, BCD, PWM, UART, IIC…), so as to detect the water level and output the signal to the output terminal.
The greatest advantage of capacitive liquid level detection is that it can detect the water level in the container or the change of the liquid through any medium, which greatly expands the practical application. At the same time, it effectively avoids the disadvantages of poor stability and reliability of traditional liquid level detection methods.
For the problems that cannot be detected in some special fields, the capacitive level switch using the ADA capacitance detection chip with built-in dual-core MCU processing can achieve many special control functions, and even realize more integrated and intelligent water level detection functions. For example, in applications such as solar water heaters and coffee pots, the change of the water level after power failure can also reliably detect the current water level. Capacitive liquid level detection is currently the most advantageous detection method among liquid level switches.
Float level switch
The float level switch uses a microswitch for contact output. When the angle of the upline above the horizontal plane exceeds 28°, the steel ball inside the float level switch will roll and press on the microswitch or disengage from the microswitch, causing the contact signal of the level switch to output as ON or OFF.
There is another type of float level switch that uses a mercury switch for contact output. When the liquid level rises and touches the float, the float changes in angle with the water level rising, centering on the weight. When the angle of the upline above the water surface exceeds 10°, the level switch will have an ON or OFF contact signal output.
Technical advantages of the float level switch: The float switch does not contain components such as bellows, springs, and seals that can cause failures. Instead, it uses a direct float to drive the magnet inside the switch, and the simple lever of the float switch makes the switch act instantaneously. The design of the angular limit of the float cantilever prevents the float from being vertical. The float level switch is a liquid level controller with simple structure, convenient use, and high safety and reliability. It is faster than general mechanical switches and has a longer working life; compared with electronic switches, it has the characteristic of strong anti-load impact ability, and one product can achieve multi-point control. It has been widely used in shipbuilding, papermaking, printing, generator equipment, petrochemical industry, food industry, water treatment, electrical engineering, dye industry, hydraulic machinery, and other aspects. The float switch is a liquid level control device with simple structure, convenient use, and high safety and reliability. It has the characteristics of being smaller in size, faster in speed, and longer in service life than general mechanical switches. Compared with electronic switches, it has the characteristic of strong anti-load impact ability.
The most prominent feature of the float type liquid level switch is that it has a float with a rod. As the liquid level changes, the rod linked to the float changes accordingly, thus controlling the closing of the switch. Industry has long used floats to measure the water level in water towers.
Currently, the most widely used one is the foamed float type liquid level switch, which is popular due to its simple installation, low price, and long service life.
Its main features:
It is used to detect the horizontal position of various solids and powders;
It can detect low or high density powders with excellent performance; It has a long life cycle; There is no need to adjust the sensitivity according to the measured material;
It is suitable for low density powders.
It is especially suitable for EPS (expanded polystyrene) machines;
It is suitable for polystyrene foam with very low density.
