Questions and answers about liquid level measurement.
Level switch vs transmitter
What is the difference between a level switch and a level transmitter?
A switch will turn on or off at a predetermined liquid level, perhaps to protect a tank from overflowing or to maintain a minimum / maximum level in the tank. The switch output is typically either a voltage free contact or if it is an electronic switch, a fixed voltage e.g. 12 volts when ON and 0 volts when OFF.
A transmitter has a variable output signal, 4 to 20 milliamps current loop is the most common. e.g. level transmitter for a 10 metre high tank, will read 4mA if the tanks is empty, 12mA if half full and 20mA if full.
Featured liquid level measurement products
Water Level Transmitters with 4-20mA Output - Browse for 4-20mA water level transmitters using two-wire loop power. Ideal for wells, tanks, rivers & reservoirs with excellent noise immunity & long cable runs.
LMP307 Submersible Level Transmitter - Submersible level transmitter for measuring liquid level with a 4-20mA current loop or a 0-10V voltage output plus optional ATEX approval for intrinsically safe use in hazardous areas in ranges from 1mH2O up to 250mH2O. The LMP307 is suitable for use on potable water with no leaching, and can be supplied with a drinking water certificate according to DVGW and KTW.
Related Help Guides
- Determining the hydrostatic pressure range for a tank level sensor
- Measuring liquid level in a sealed tank with a hydrostatic pressure sensor
- Difference between vented and non-vented water level measurement
- How do you measure the volume of a liquid using pressure
- Measuring liquid level in a tank using a dp sensor
Related Technical Terms
- Capacitive Fluid Level Measurement
- cmH2O – Centimetres of Water Column at 4 deg C Pressure Unit
- Conductive Fluid Level Detection
- Float Fluid Level Detection
- ftH2O – Feet of Water Column at 4 deg C Pressure Unit
- mH2O – Metres of Water Gauge at 4 deg C Pressure Unit
- mmH2O – Millimetres of Water Column at 4 deg C Pressure Unit
- Specific Gravity
- Vibrating Tuning Fork Fluid Level Detection
Related Online Tools
- Liquid Level to Hydrostatic Pressure Calculator
- Fluid Depth, Density, Gravity, and Pressure Calculator
- Liquid Level Transmitter 4-20mA Current Output Calculator
- Vertical Cylindrical Shaped Tank Contents Calculator
- Horizontal Cylindrical Shaped Tank Contents Calculator
- Rectangular Shaped Tank Contents Calculator
- Pressure to Liquid Level Calculator
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