Level sensor: Sonar design monitors level and liquid condition

By Control Engineering Staff March 22, 2007

ORCA level gage is excellent for water and wastewater processing applications.

The new ORCA series of sonar level measurement devices from Hawk Measurement Systems , offers a variety of capabilities that reportedly extends its usefulness beyond simple tank volume. First, it features a range of frequencies to allow it to select the best one for a specific application. Second, it has a scum-cleaning mechanism to keep itself clear continuously for accurate measurements. Third, it can actually monitor certain conditions of the tank contents.

The sonar sound pulse reflects off the surface of the liquid to determine the level, but it also travels through the liquid and bounces off the bottom of the tank. (Maximum distance, 100 ft., or 30 meters.) This secondary wave can be used to track the clarity of the liquid, monitor changes in suspended solids, and detect fluff/floc layers. Moreover, the unit measures temperature.

These functions can be configured and read via a CDMA modem for remote technical and diagnostic support. There can be one or two analog outputs to support multiple interfaces if needed. Its connectivity supports Modbus, Profibus and HART communications.

— Control Engineering Daily News Desk Peter Welander , process industries editor