Level

Level sensors and level switches

Level measurement and level switch: capacitive level sensors and level switches, ultrasonic level measurement, conductive level switches, hydrostatic sensors, tuning forks and float switches.

Level sensors detect the level of liquids and fluidised solids, including slurries, granules and powders. Media that flow through gravity essentially horizontally into their containers (or other physical boundaries), while most bulk solids accumulate at an angle of rest into a pyramid. The medium to be measured may be in a container or in its natural form (e.g. a river or a lake).

The level measurement can be either a continuous value or a switching point.

• Continuous level sensors display a value (level height or level depth). This can be used to calculate the contents of a tank, for example.
• Level switches only show whether a certain level has been reached or not. These are often used in simpler applications or in conjunction with a continuous measurement as security. The protection can serve as a maximum protection (overflow protection) that prevents the tank from overflowing if the continuous level measurement does not work properly. Or it can provide a minimum level, for example as protection for a pump to prevent it from running dry.

Choices for optimal level monitoring

There are many physical and application variables that influence the choice of the optimal level monitoring.

Some selection criteria for a level measurement include:

• The physical: phase (liquid, solid or suspension)
• Temperature
• Pressure or vacuum
• Medium
• Dielectric constant of the medium
• Density (specific gravity) of the medium
• Acoustic or electric noise
• Vibration, mechanical shocks
• Size and shape of the tank or receptacle

Also important are the application restrictions:

• Price
• The market in which it is applied.
• Installation possibilities
• Accuracy
• Response speed
• Ease of calibration or programming
• Physical size and mounting of the instrument
• Monitoring or control of continuous or discrete (point) levels.

In short, level sensors are among the most important sensors and play a very important role in a variety of applications. As with other types of sensors, level sensors are available or can be designed using a variety of detection principles. The choice of a suitable type of sensor that meets the application requirements is very important.

Types of level sensors and level switches

Some of the principles that Ebora has in its program for level sensors and level switches are:

• Radar level sensors
• Ultrasonic level sensors
• Capacitive level sensors and capacitive level switches
• Float switches
• Vibrating fork level switches
• Optical level switches
• Magnetostrictive level sensors and switches
• Magnetic level gauges
• Hydrostatic level sensors
• conductive level sensors and conductive level switches