Capacitive level controls are widely used to control the level of substances both solid and liquid which may not be conductive. They are particularly used in silos for cereals, foodstuffs and the food industry in general. They are also used in the transport, dosing, stocking and handling of plastic materials, in foundries and cement factories. They are supplied as a probe with aluminum housing and electrode rod or steel wire rope teflon-coated, in addition to the range of capacitive sensors with rapid or delayed switching, with M18 and M30 threaded cylindrical housing with fixing nuts.
They work on the resistivity of liquids and sense the level via the electrodes placed in the conductive liquids.
The presence of liquid between the electrode (or electrodes) and the metal surface of the container (or earth electrode)
causes the functioning of the electronic circuit in the control unit and the subsequent commutation of the output relay.
They are used as level controls in tanks, heaters deep wells and other containers and as alarm units for overfilling and the checking of ice accumulation.
They are used for the level control in containers holding product in powder or granule form. The body is made of plastic material. The functioning is based on the slow rotation of a syncronous motor which turns the paddle which is placed in the container. In the absence of material the paddle turns, material coming into contact with the paddle causes a breaking effect which slows down the motor and in turn causes the unit to switch.
This unit is suitable for controlling the maximum and minimum levels in silos and tanks containing materials such as powder or granule, such as rice, cereals, plastic material, coffee, etc.
Its functioning is due to the pressure created by a product on the rubber membrane which activates a microswitch.
The sensitivity of the switching can be adjusted in depending on the material to be sensed as a function of its specific weight. Variations in humidity and temperature do not compromise the functioning, furthermore the membrane is resistant to blows and vibrations.
Magnetic float level controls for liquids are made of a reed contact placed inside the shaft and an operating magnet placed in the float which runs due to the increase or decrease of the liquid to detect. The working principle the same as our magnetic sensors.
There are 3 models available: one made of plastic housing and two made of AISI 316 stainless steel suitable for high temperatures of +100°C e +150°C.
Our housing is to be mounted as a waterproof protection to our M30 capacitive sensors. Our SCM housing is made of nontoxic plastic material, suitable for food applications. Temperature range from -20 ÷ +70°C, max pressure inside the tank no greater than 8 bar and threaded 1”1/2 connection. SCM protection housing simplifies the sensor replacement in case of malfunction. This can be used combined with our ATEX approved capacitive sensors series AD3 group II, category 3; suitable for potentially explosive zone 22 environments due to the presence of gas and dust ‘D’ mixtures, in conformity with CE Directive 94/96.
These M18 and M30 sensors should be considered as part of the traditional range of capacitive sensors with the difference that electronic portion is completely separate from the sensing part which is in the form of an extension and can withstand temperatures from -200°C to +250°C. These products are used to control the levels of hot materials such as liquids, oil, powder and plastic granules. They also sense solid metallic and non-metallic bodies positioned in areas of high temperature.
The connecting cable between the sensor and the amplifier must be of standard length (2mt or 5mt). It is connected to the sensor and it is provided with a shielded connector for connection to the amplifier.