Back to top

Echotel® 961 ultrasonic level switch for hygienic applications

Echotel® Model 961 Ultrasonic Level Switches use pulsed 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 a wide variety of hygienic level switch applications.

Model 961 is offered with either a 5-amp relay or a current shift electronics. The relay output electronics has a DPDT relay for level detection, and a SPDT malfunction relay. The current shift version indicates 8 mA during normal operation, 16 mA as a level alarm condition and a user-selectable 3.6 or 22 mA malfunction indication.

The Model 961 switches are designed for the stringent requirements of hygienic applications. These switches are offered with a deep-drawn 304 stainless steel housing that is favorable to CIP and SIP procedures. A 20 Ra surface finish is featured with hygienic Model 961 transducers. These transducers are available with 11⁄2" and 2" Tri-Clamp® fittings, and DN65 Varivent® Type N flanges.

Echotel 961 Hygienic
Technology

Ultrasonic contact

Ultrasonic contact switches use a pair of piezoelectric crystals that are encapsulated in epoxy at the tip of the transducer for level measurement. 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.

Ultrasonic contact

Features

  • Self-test technology provides unsurpassed reliability and testing of electronics, transducer, piezoelectric crystals, and electromagnetic noise
  • 20 Ra surface finish with Tri-Clamp and Varivent fittings
  • Adjustable time delay for turbulent aerated liquids
  • Tip-sensitive transducer measures level within ¼" of the vessel bottom
  • Pulsed signal technology provides superior performance in difficult process conditions

Options

  • Deep drawn 304 stainless steel or cast aluminum housings
  • Glass window cover
  • NPT, Tri-Clamp, or Varivent process connections

Operating principle

Model 961 switches use pulsed signal technology to detect the presence or absence of liquid in an ultrasonic transducer gap. The transducer uses a pair of piezoelectric crystals that vibrate 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 and converts it back into an electrical signal. This signal is sent to the electronics to indicate a wet gap condition. When no liquid is present, the ultrasonic signal is attenuated and is not detected by the receive crystal.

Challenging process conditions like aeration, suspended solids, and high viscosities are overcome by using pulsed signal circuitry in Model 961 switches. Unlike many tuning forks, pulsed signal ultrasonic switches do not need to be configured for different media densities, making these units the most universally applied level switches on the market today.

Ultrasonic contact
Ultrasonic contact

Approvals

XP=Explosion Proof, IS=Intrinsically Safe, NI=Non-Incendive, NS=Non-Sparking, ELV=EMC/Low Voltage

CSA IS, NI
FM IS, NI
SIL SIL 2 (1oo1)

Other approvals are available. Consult factory for more details.

Downloads

Instruction manuals

Echotel® 961/962 Line Powered I&O Manual
The Echotel® 961/962 series utilizes pulse signal technology to detect high or low level alarm(s) in a broad range of viscous...
Echotel® 961/962 Loop Powered I&O Manual
The Echotel® 961/962 series utilizes pulse signal technology to detect high or low level alarm(s) in a broad range of viscous...

Product catalogs

Echotel® Model 961 Hygienic
Echotel® 961 ultrasonic level switches require no calibration to detect the presence of any liquid in less than 1s. Foam is...

Do you want personal advice for your specific control process?

Contact your local Magnetrol representative!

Find your local representative or contact us with any questions.