Device for measuring liquid level and converting it to an electrical signal to send to other instrumentation.
A liquid level sensor is an instrument for measuring the height of a liquid and converting it to an electrical signal which is sent to other instrumentation to display, monitor, log or control the liquid level.
There are many different types of technology use to measure liquid level, there are sensors that can be mounted above the liquid such as ultrasonic or radar which bounce a sound or electromagnetic wave off the surface of the liquid and use the travel time to determine the distance from the liquid surface.
For liquid filled tanks there are sensors which can be attached externally, such as floats running up and down a liquid filled tube connected at the bottom of the tank, or a pressure sensor installed in a hole in the bottom of the tank which measures the pressure generated by gravity acting on the liquid.
Another method is to lower a probe into the tank and immerse it in the liquid such as a capacitive probe which detects the changing capacitance charge as the length of the probe is exposed to varying proportions of liquid and air, or pressure sensors which measure the pressure generated by gravity acting on the surrounding liquid.
Related Products
Hydrostatic Level Sensors - Hydrostatic pressure sensing devices for measuring liquid level and converting it to an electrical signal to send to other instrumentation.
External Mounted Tank Level Sensors - External mounted level sensors for installing on the outside of a liquid storage tank to measure level of tank contents. 
Waste Water Level Sensors - Waste water Level sensors with open face flush diaphragms for measuring the hydrostatic pressure of sewage and effluent waste. Select a level sensor for mounting inside or external to a tank or sewer pipe.
Water Level Transmitters with 4-20mA Output - 4 to 20 mA current loop output water level transmitters with a for use with process instrumentation for measuring the level of water in a water well, water reservoir, river or water storage tank.
Chemical Resistant Hydrostatic Liquid Level & Pressure Sensors - Pressure transmitters & transducers that are resistant to chemical corrosion for measuring the hydrostatic level of storage tanks or process pressures.
Low Range, Shallow Depth Liquid Level Sensors - Level sensors for measuring very low liquid levels in shallow rivers, weirs, drains, sewers, streams and small tanks which are immersed or mounted on the outside of a tank.
Diesel Fuel Tank Level Sensors - Diesel fuel oil storage tank device for measuring diesel fuel level and converting it to an electrical signal to send to other instrumentation.
Submersible Liquid Level Sensors - Devices protected from liquid ingress when completely immersed in a fluid for measuring liquid level and converting it to an electrical signal to send to other instrumentation.- ATEX Approved Liquid Level Sensors for Hazardous Areas - European hazardous area ATEX approved sensors for liquid level measurement in intrinsically safe installations on petrochemical, pharmaceutical, landfill and sewage treatment sites.
- 4-20mA Output Hydrostatic Level Transmitters & Sensors - Liquid level transmitters with a 4 to 20 milliamp current loop output signal for determining liquid depth or the fluid level by measuring the hydrostatic pressure.
- Submersible Hydrostatic Level Sensors & Probes - Level sensors for submerging permanently in liquid to determine the level or depth of fluid by measuring the hydrostatic pressure.
Sea, Brackish or Salt Water Submersible IP68 Depth & Level Sensors - IP68 rated transmitters and transducers suitable for use with tidal and coastal salt water.
DMP331P Hygienic Flush Pressure Transmitter- LMK809 Plastic Submersible Low Level Transmitter
ATM/N Titanium Submersible Hydrostatic Pressure Transmitter- LMK382 Low Range IP68 Waste Water Level Transmitter
LMK306 Ground Water Level Transmitter- LMK458 Marine Approved Hydrostatic Level Transmitter
LMP307 Submersible Level Transmitter
S12S SDI-12 Coms IP68 Pressure and Temperature Sensor- IMCL Low Cost Submersible Pressure Sensor
- LMK387 Cleanable Sewage and Sludge Pressure/Level Sensor
DMK 458 Seawater Low Range Pressure Transmitter
18.605 G Low Cost Submersible Diesel Fuel and Water Tank Level Sensor
- High temperature water level transmitter for measuring up to 1 mWG
- Underground rain water storage tank level sensor and readout for 2 metre depth
- 2m tank height, high temperature oil level sensor with 4-20mA out
- Remote water tank level monitoring via GSM mobile network
- Borewell water level sensor for 100m water height
- 200m deep well pump water level sensor, switch & display
- Cooling tower basin water level transmitter
- Modbus RTU RS485 submersible borehole water level sensor
- Beverage tank liquid level sensor for beer, wine, spirits or cider
- Underwater 50 metre sea depth 4-20mA output sensor
- 25m borehole submersible pump level indicator and control switch with level sensor
- 3m range 4-20mA output submersible hot water tank level sensor
Product Type Comparison Table
Please use the table below to compare the advantages and disadvantages of each liquid level sensor technology type versus application and specification parameters.
| Capacitive | Hydrostatic | Ultrasonic | Radar | |
|---|---|---|---|---|
| media contact | yes | yes | no | no |
| moving parts | no | yes | no | no |
| surface disturbance sensitive | no | no | yes | no |
| pressurised vessel | yes | more difficult | yes | yes |
| vacuum evacuated vessel | yes | more difficult | no | yes |
| installation position | top | side, bottom | top | top |
| thick fluids | no | yes with flush diaphragm | yes | yes |
| protrusion into tank | yes | no | no | no |
| sg density variation sensitive | yes | yes | no | no |
| fouling degrades performance | yes | yes | no | no |
| accuracy | low | high | high | high |
| cost | high | high | high | high |
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