What is level measurement? Types of level measurement

What is level measurement?

The level can be defined as the filling height of a liquid or some type of material in a reservoir or container. Measurement is normally carried out from the bottom of the container towards the surface or a reference point of the material to be measured. 

The application of level measurements is necessary for many processes, such as measuring the level of 

1. Grains in silos, 
2. Fuel in fuel tanks, 
3. Water in water tanks, 
4. The level of lakes and oceans etc.

The variety of methods in this type of measurement is also wide. Nowadays, there are gauges that employ techniques such as floats and pressure measurement by differential pressure, among others. 

Another common factor, mainly due to the introduction of electronic processors in instrumentation, is the integration of level measurements to other process tasks, such as transmission, control, and filters, in addition to the possibility of remote procedures, such as calibration and interaction with other parts of the process.

A very common fact in level measurement is the application of detectors. In this case, systems are implemented that monitor states of levels, such as the state of maximum level and state of minimum level. It is still possible, with this type of procedure, to monitor the level of a given product according to the number and position of the detectors, which characterizes a digital output.

Types of  level measurement

There are two types of level measurement

1. Level Measurement by Direct Methods
2. Level Measurement by Indirect Methods

Level Measurement by Direct Methods

Direct methods are those in which techniques are used that directly measure the height of the surface in relation to the bottom of a container such as

1. Level indicators and sight glasses
2. Level gauges with buoys and floats
3. Magnetic level indicator

Level Measurement by Indirect Methods

The level measurement by indirect methods is performed using magnitudes related to the level, such as buoyancy force, propagation time, pressure, capacitance, etc. Example includes

1. Displacer type level meter
2. Hydrostatic level measurement
3. Weighing level meter
4. Capacitive level meter
5. Conductivity level meter
6. Ultrasonic level meter
7. Level measurement by vibration
8. Radar level measurement
9. Radiation level meter
10. Magnetostrictive level sensors
11. Laser level transmitters