How do you measure the depth of water?

Water depth sensors are also known as water level sensors. Water depth sensors are often used to measure tank levels, well depths, river depths, etc. There are many different types of water depth sensors. All of them are used to measure the water level by submerging underwater or above the water surface. Then, they are converted into a water depth or water level signal. For example, submersible hydrostatic level meter, ultrasonic level meter, etc.

Water depth sensor- Water level sensor Solutions

At present, the common measurement principle of liquid level meter in the industry involves mechanics, thermal, electrical, optical, and other aspects. The product models even reach hundreds of kinds. Of course, different types of level meters mean that they are produced, used, and calibrated in different ways. It is not possible to fit all measurement environments.

Water Depth/Level Sensors Types

The following will be from the perspective of the measurement method, for the current market more than ten kinds of liquid level meter classification. To help users in the selection of products to make the appropriate choice.

Water Depth Sensors measured by buoyancy

The buoyancy type level meter has a float (float ball or float). The float is in equilibrium on the static liquid level. When the liquid level changes, the float is displaced with the liquid level. The electronic component acquires the float displacement in a certain way. And then converted to the liquid level change.

Due to the different ways of receiving float displacement by electronic components, the buoyancy method liquid level meter is divided into magnetic flap level meter, float level meter, magnetostrictive level meter, etc.

Magnetic level meter consists of magnetic float, cylindrical container, scale and transmitter.

The float moves with the liquid level in the container, and the magnetic field of the float acts on the sensor. The sensor is a strip of rubber-sealed in a stainless steel tube of equal length to the measured liquid level. There are numerous reed switches welded to it at intervals of 1cm or less.

When the reed switch is at the same level as the float, it closes. Otherwise, the transmitter receives the current signal generated by the amount of resistance connected to the reed switch, which is converted to the liquid level.

Float movement is shown on the scale as a red and white bead flip, indicating the liquid level.

Extended reading: Water Tank Level Controller

Float level meter has a float, spring, magnetic steel chamber and indicator, designed according to Archimedes’ law and magnetic coupling principle.

The displacement of the float causes the magnetic field of the magnet chamber to change. The magnetic sensor inside the indicator precisely measures the change of the surrounding magnetic field.

Float Level Sensors – Single and Multipoint

The magnetostrictive level meter is mainly composed of float, waveguide, and transmitter.

The electronic component of the transmitter generates a low-voltage current pulse, which starts timing and generates a magnetic field that propagates down the magnetostrictive line.

The float moves along the measuring rod as the level changes, and the magnet inside the float also generates a magnetic field. When the two magnetic fields meet, the magnetostrictive lines are twisted to form a torsional stress wave pulse. The velocity of the pulse is known, and the pulse propagation time is calculated to correspond to the exact change in the liquid level.

Magnetostrictive Level Transmitters

Extended reading: Magnetostrictive Hydraulic Cylinder Position Sensor

Liquid level meter measured by pressure

The level meter of pressure method is the level meter that reflects the liquid level by measuring the liquid pressure through its pressure measuring element. It is generally composed of transmitter, sensor and pressure probe. The sensor is a special metal rod or cable with a built-in capillary hose, and the probe is constructed as a stainless steel cylinder core with a diaphragm at the bottom.

The probe intrudes into the liquid and tests the difference between the static pressure of the liquid and the actual atmospheric pressure, which varies with the liquid level. The electronic components receive the differential pressure signal to reflect the change in liquid level. According to the different materials of sensors are divided into two types of rod and cable type.

Rod type pressure level meter sensor is a metal rod. Its general technical parameters are, the measurement range is generally 0 ~ 5m, output signal: (4 ~ 20) mA, measurement accuracy is generally ± 0.5%.

SMT3151TR Submersible Level Transmitter
Hydrostatic level transmitter is also called hydrostatic level gauge. The rod-type Hydrostatic level transmitter 4-20mADC standard signal output. Flange or threaded installation. Can withstand high temperatures up to 450 ℃.

Because the sensor is a cable, can be bent, convenient handling and loading, so the range of the cable type pressure level meter can be very large, there are 100m, or even 300m, its measurement accuracy is generally ± 1.0%.

SI-151 Hydrostatic Level Sensor
Hydrostatic Level Sensor (Best Price), also called Hydrostatic level transmitter. Continuous level measurement in liquid applications with pressure sensors.

Differential pressure level meter is also through the detection of pressure differences to measure the liquid level.

The level meter has two pressure-taking ports in the gas phase and liquid phase.

The pressure at the gas phase pressure point is the pressure of the gas phase in the equipment. The pressure at the liquid phase pressure point is not only affected by the gas phase pressure, but also by the static pressure of the liquid column.

The difference between the liquid phase and gas phase pressure is the static pressure generated by the liquid column, which is converted into the liquid surface height.

Liquid level meter measured by reflection

At present, there are two main types of reflective level meters: radar level meter and ultrasonic level meter. Their principles are basically the same, they are through the emission – reflection – reception of ultrasonic or electromagnetic wave (radar wave) way to measure the liquid level height.

Radar level measurement uses Non-contacting radar technology for Continuous level measurement. Liquids and solids are commonly measured with this measuring technique.

Non-Contacting Radar Level Measurement

Radar level transmitters use radar technology to perform non-contact continuous level measurement. The radar level indicator converts the level into an electrical signal. The level signal output can then be utilised by other instrumentation to monitor or control. Liquids and solids are commonly measured with this measuring technique. Like: Fly ash silo. Radar level sensors are divided into: Pulsed radar technology and frequency modulated continuous wave (FMCW) radar level sensors.

Sino-Inst produces a 120GHz FMCW radar level sensor, 26GHz radar level meter, 6GHz level meter.

Extended reading: Radar Level Meter for Corrosive Liquids

Extended reading: Radar Water Level Sensor Applications

Ultrasonic Level Sensing sensors and transmitters are used for continuous, non-contact level measurement.

Ultrasonic Level Sensing

Ultrasonic Level Sensing is a low-cost liquid level measurement technology. Ultrasonic Level Sensing sensors and transmitters are used for tank or river level measurement. Ultrasonic Level Sensing does not need to contact the medium, can be continuously measured at low cost. Therefore, Ultrasonic Level Sensing is very popular among users. Ultrasonic liquid level sensors are available in general and intrinsically safe types. Output 4~20mA standard signal or output the measurement result to the secondary meter through RS-485. Meets the system’s automatic control.

Extended Reading: Wireless Water Meter

Liquid level meter through the conductive method of measurement

Level meters in the conductive mode are based on the electrical principle. The level is measured by means of measuring capacitance or resistance. This type of level meter mainly includes capacitance level meter, radio frequency conductivity level meter, resistance level meter.

The Capacitance level meter uses the change of measuring capacitance to measure the level of the liquid.

By a metal rod inserted into the liquid container, the metal rod is a pole of capacitance, the container wall is the other pole of capacitance. The medium between the two electrodes is the liquid and the gas above it.

As the dielectric constant of the liquid and the dielectric constant of the gas on the liquid surface is different, the level of the liquid is measured by the change of the capacitance between the two electrodes.

Extended reading: Capacitive water level sensor

RF conductivity level meter is an upgraded version of capacitance level meter, which can be understood as measuring conductivity with high frequency radio waves.

When the instrument works, the sensor of the instrument and the filling wall, and the measured medium form the conductivity value. When the level changes, the conductance value changes accordingly. The circuit unit converts the measured conductance value into a level signal output. To achieve the level measurement.

Extended reading: Radar Non Contact Water Level Sensor

Deep Well Water Level Sensor

SI-PCM260 Deep Well Water Level Sensor

Deep Well water level sensor is to apply Hydrostatic Level Sensor to deep well. The Well water level sensor submerged in deep well works together with a submersible water pump. The range within 300m ~ 1000m.

Deep Wells Water level sensor is based on the principle that the measured liquid pressure is proportional to the height of the liquid. The piezoresistive effect of the advanced foreign isolated silicon diffused sensor is used. Change to electrical signal. After temperature compensation and linear correction, convert to 4-20mA standard electrical signal. Well water level sensor submerged in deep well work together with water pump. It is extremely difficult to replace and submit an inspection. Therefore, it adopts stainless steel cable, waterproof, sealing ring, and other four-level seals. Special cables and special water sealing technology make the transmitter highly reliable and stable.

Extended Reading: 3 inch (3″) Water Flow Meter

Portable Ultrasonic Water Depth Gauge

HS-SFCC Portable Ultrasonic Water Depth Gauge

Water Depth Gauge is a portable water depth detector based on the principle of ultrasound. Ideal water depth measuring instrument for ships, oceans, reservoirs, lakes, rivers, and shallow water level monitoring.

Water Depth Gauge is a necessary instrument to measure water depth in reservoir, lake, river, shallow sear. Place ultrasonic transducer on water surface or into a certain position into water. The device can caculate current water depth. HS-SFCC Portable Ultrasonic Water Depth Gauge It has perfect water depth measurement function. Control function, data transmission function and man-machine communication function. This machine integrates ultrasonic transceiver sensor, servo circuit, temperature compensation sensor and compensation circuit unit, display, control signal output and serial data or analog output unit (optional) as a water depth measuring instrument. It has the characteristics of low maintenance, high reliability, long life, convenient use, simple operation and accurate measurement. Therefore, it is widely used in water area monitoring.

Read more about: Common River Water Level Measurement Methods

How do you measure water level in tank with sensor?

Water Tank Level Sensors for Level Control

The Water Tank Level Sensor is an important part of the water tank level control system. Using a level sensor for the water tank, solenoid valve, control box, liquid level switch and other accessories can effectively form a Water Tank Level control system. Monitor the materials stored in the water tank. Master important data such as its liquid level, reserves, and quality. A reasonable liquid level can ensure the safe, reliable, and efficient operation of the storage tank.

Read more about: Water Tank Level Sensors for Level Control

More Level Measurement Solutions

Sino-Inst offers over 20 Water depth sensors for level measurement.

About 50% of these are liquid level meters, 40% is the tank level sensor.

A wide variety of Water depth sensors options are available to you, such as free samples, paid samples.

Sino-Instrument is a globally recognized supplier and manufacturer of level measurement instrumentation, located in China.