Lollipop switch is a level of equipment that measures the height and level of fluids and liquids that are in the tanks. Swing switches react to changes in the height of fluids and solids and control tank surfaces. The main mechanism of the roll switch is to determine the amount of material, adjust and control the cut-off and connection of the output in the set point. Surface switches are one of the most widely used sensors in the industry and are widely used in the oil, gas, petrochemical, pharmaceutical and other industries.
Types of switches
The types of level controllers in the industry are as follows:
- Capacitive switch switch
- Induction switch lever
- Level diaphragm switch
- Dislocation or displacement switch
- Float or float switch
- Light switch
- Lollipop switch
- Vibration switch or range or fork
Capacitive level switch
Capacitive switch switch is one of the level measuring equipments that is installed on tanks to measure surfaces and the dielectric coefficient is more than 10 for conductive fluids and less than 10 for non-conductive fluids. In non-conducting fluids, a capacitive sensor is used and the capacitor is created with a capacitive probe and a metal tank wall. In conductive fluids, two capacitive sensors are used.
Capacitive surface switches are contact sensors and are suitable for measuring the level of liquids, powdered solids and non-metallic materials and are used in the plastics, chemical, wood, ceramic and glass industries and the packaging industry. Also, these switches do not require maintenance.
Induction switch level
Induction switch coils are used in liquids with electrical conductivity of at least 10 microseconds per centimeter. Some level switches have the ability to detect 5 level heights. Induction surface switches are contact sensors that are generally suitable for liquids but are used in some applications for paste or slurry, ponds, tanks, reservoirs, drugs, closed vessels, and open tanks.
Level diaphragm switch
Diaphragm level switches are contact sensors and are very sensitive and cost-effective. Diaphragm switches operate mechanically and do not require a power supply, transferring pressure on the thin diaphragm wall to a microswitch and monitoring the condition of the tanks for full or empty. A wide range of apertures is available depending on product volume density, flow rate, wear and temperature. These switches are used in applications such as mining, silos, funnels and food beverages.
Displacement level switch
The displacement switch switch operates according to the principles of buoyancy, in that the floating ball is attached to a spring and at the other end is a magnet. When the fluid level rises, the spring shrinks and pushes the magnet slightly, and this interaction causes the electrical connection and the switch. The level controller is not affected by turbulence or pressure. These surface switches are very suitable for use in viscous or dirty liquids. Displacement surface switches are used in refineries for heavy oil, paint varnishes and chemical plants.
Float or float level switch
The float level switch is a contact sensor, which consists of a float that rotates around an axis. When the fluid level reaches the set point, the float rotates around the axis and using a magnetic sensor, the output is sent as a contact.
Float level switches are used in applications such as surface control, valve control, meters, fluid tanks, oil level control, drip bases and boilers.
Optical level switch
Optical surface switches include an optical transmitter and receiver and operate based on the radiation and reflection of light from the surface of objects or the passage of light through the fluid. Optical level controllers measure the surface in two ways:
- Positioning the receiver and transmitter of light waves in front of each other
The light emitted from the transmitter continues its path into the tank to reach the receiver. When the fluid level rises and the fluid is placed between the receiver and the transmitter, the light beams are deflected by the refractive effect and do not reach the receiver, in which case the output of the level gauge is activated.
- Position the receiver and light transmitter on top of the tanks and next to each other
The sensor measures the fluid level inside the tank by measuring the return time of the light emitted by the transmitter. If the height of the fluid inside the tank decreases, the return time of the light increases and vice versa.
Optical level switches provide fast response and are used in air conditioners, collectors, pharmaceutical hydraulic tanks and liquid storage tanks.
Blade level switch
The blade switch coil consists of a metal blade that is driven by an electric motor. As soon as the material surface reaches the rotating blade, it prevents the blade from rotating, and the force caused by the blade standing causes the motor to move off its axis and activates the microswitch in the rotary switch. The microswitch sends an electrical signal when the tank is full or empty. The blade surface switches are contact sensors and are used in applications such as mining, silos, funnels, food beverages and grain silos.
Vibration level switch (range, fork)
Range-level switch switches are vibration sensors with a blade in which the blade oscillates with a certain frequency. If the blade collides with the fluid inside the tank, its oscillation frequency will change. By measuring this frequency change, the fluid level can be measured at the desired height. Measured and controlled the level. Vibration level switches are contact sensors. These roll switches are cost-effective and suitable for controlling the level of powders and fine solids and are used in applications such as mining, chemical processing and food beverages.