Liquid Level Sensors

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.

Contents

Product Types

Hydrostatic Level Sensors - Hydrostatic pressure sensing devices 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.
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.
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.
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.
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.
Detachable Cable Submersible Liquid Level Sensor Probes - Sensor probes with removable submersible signal cable for measuring liquid level. These sensor probes can be easily replaced without the need to remove the installed cable assembly or break connections to cable junction boxes and termination enclosures.
Marine Approved Submersible Liquid Level Sensors - Marine approval certification for use on ships. Protected from liquid ingress when completely immersed in a fluid. Device for measuring liquid level and converting it to an electrical signal to send to other instrumentation.

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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