Image Credit: Carlton-Bates Company | First Sensor AG | CARLO GAVAZZI Automtation Components
 

Dry material level sensors are used to measure levels of solid, dry materials (powders). These level measurements can be either continuous or point values represented with various output options. Continuous level sensors are devices that measure level within a specified range and give output of a continuous reading of level. Point level sensors devices mark a specific level, generally used as high alarm or switch. Multiple point sensors can be integrated together to give a stepped version of continuous level.

Considerations for Dry Materials Level Sensors

The measuring range is probably the most important specification to examine when choosing dry material level sensors and powder level sensors. Field adjustability is a nice feature to have for tuning the instrument after installation.

Output

Dry material level sensors and powder level sensors can be either plain sensors with some sort of electrical output or else can be more sophisticated instruments that have displays and sometimes computer output options.

Mounting

Depending on the needs of the application, level sensors can be mounted a few different ways. These devices can be mounted on the top, bottom or side of the container holding the substance to be measured.

Technology

Among the technologies for measuring level are air bubbler technology, capacitive or RF admittance, differential pressure, electrical conductivity or resistivity, mechanical or magnetic floats, optical units, pressure membrane, radar or microwave, radio frequency, rotation paddle, ultrasonic or sonic and vibration or tuning fork technology.

Analog outputs from dry material level sensing devices and powder level sensing devices can be current or voltage signals. Also possible is a pulse or frequency. Another option is to have an alarm output or a change in state of switches. Computer signal outputs that are possible are usually serial or parallel.

 
Display

Dry material level sensors and powder level sensors can have displays that are analog, digital or video displays.

Control

Control for the devices can be analog with switches, dials and potentiometers; digital with menus, keypads and buttons; or controlled by a computer.

Additional Features

Some features that can make dry material level sensing devices and powder level sensing devices more desirable are being programmable, having controller, recorder or totalizer functions and a built-in alarm indicator, whether audible or visible. Also important for some applications are sanitary ratings and the ability to handle slurries with suspended solids, such as wastewater or sewage.