Echotel Model 961/962 Ultrasonic Level Switches

Increasing demands for compliance with safety systems and overfill protection has mandated more reliable point level measurement. Echotel Models 961 & 962 Ultrasonic Level Switches meet these demands with reliable transducer designs, extensive hazardous location approvals, and an advanced self-test technology. Model 961 offers the ultimate solution to reliable single point liquid level measurement. This advanced switch usespulsed signal technology for superior performance in difficult process conditions, and to provide excellent immunity from sources of electrical noise interference. Extensive self-testing of the electronics and transducer make this advanced switch suitable for use in Safety Integrity Level (SIL) 2 loops.


Model 962 is a dual point switch that can be used as a level controller, or to control pumps in an auto fill or auto empty mode. The tip sensitive lower gap performs well in aerated or foamy liquids, and can measure to within 1⁄4″ of the vessel bottom. The rigidity of the unique flow-through upper gap allows separations of up to 127″ (322 cm) between the upper and lower transducer gaps.

Technology of Echotel Model 961/962 Ultrasonic Level Switches

Echotel Model 961 962 Ultrasonic Level Switches 1

Model 961/962 switches utilize ultrasonic energy to detect the presence or absence of liquid in a single or dual pointtransducer. Ultrasonic contact level technology uses high frequency sound waves that are easily transmitted across a transducer gap in the presence of a liquid media, but are attenuated when the gap is dry. Model 961/962 switches use an ultrasonic frequency of 2 MHz to perform this liquid level measurement in a wide variety of process media and application conditions.The transducer uses a pair of piezoelectric crystals that are encapsulated in epoxy at the tip of the transducer. The crystals are made of a ceramic material that vibrates at a given frequency when subjected to an applied voltage.The transmit crystal converts the applied voltage from the electronics into an ultrasonic signal. When liquid is present in the gap, the receive crystal senses the ultrasonic signal from the transmit crystal and converts it back to an electrical signal. This signal is sent to the electronics to indicate the presence of liquid in the transducer gap. When there is no liquid present, the ultrasonic signal is attenuated and is not detected by the receive crystal

Features of Echotel Model 961/962 Ultrasonic Level Switches

  • No calibration required
  • Performance independent of liquid type or properties such as density (SG)
  • Single or dual point liquid level measurement
  •  Advanced self-test and diagnostics
  • Adjustable time delay for turbulent or aerated liquids
  • Relay output or mA current shift with separate
  • malfunction indication
  • Integral or remote mount electronics
  • Pulsed signal technology
  • FM, ATEX and IEC agency approvals
  • Suitable for Safety Integrity Level (SIL) 1 and 2 loops

Applications of Echotel Model 961/962 Ultrasonic Level Switches

  • Overfill protection
  • Seal pot level
  • High/low level alarm
  • Chemical Tanks
  • Pump protection/control
  • Low density/low dielectric
  • Cryogenic liquids
  • Level with spray balls
  • Fill lines