Echotel® Model 961/962 Ultrasonic Level Switches DESCRIPTION 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 selftest technology. Model 961 offers the ultimate solution to reliable single point liquid level measurement. This advanced switch uses 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 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. FEATURES • 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 APPLICATIONS • Overfill protection • Cryogenic liquids • High/low level alarm • Level with spray balls • Chemical Tanks • Fill lines • Pump protection/control • Integral or remote mount electronics • Pulsed signal technology • FM, ATEX and IEC agency approvals • Suitable for Safety Integrity Level (SIL) 1 and 2 loops INDUSTRIES • Chemical

TECHNOLOGY BASIC OPERATION Model 961/962 switches utilize ultrasonic energy to detect the presence or absence of liquid in a single or dual point transducer. 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...

ADVANCED SELF-TEST AND DIAGNOSTICS Ultrasonic switches are often used as the last means of detecting whether a r e c process vessel will overflow and cause Transdu ls & crysta a spill of potentially hazardous liquids, ics Electron or empty out and possibly cavitate the Noise pumps. In these critical applications it is desirable to have a method of periodically testing the ultrasonic switch to ensure that it is functioning properly. Model 961/962 switches feature an advanced selftest technology that not only tests the electronics, transducer, and piezoelectric crystals, but also tests for the...

APPLICATIONS TYPICAL Model 961 single point switches may be used for high or low level alarm, as well as for pump protection. The Model 962 dual point unit is typically configured to measure high/low, high/high, or low/low levels. Common applications include safety-critical high-level alarms to conform to API 2350 or seal pot level to conform to API 682. The single point 961 can be mounted vertically or horizontally in vessels, bridles, or pipes. The dual gap 962 is always top mounted. A broad selection of transducer materials allow the 961/962 to be used in a wide variety of process media. Metallic...

ELECTRONICS SPECIFICATIONS MODEL 961/962 WITH RELAY OUTPUT Supply Voltage Relay Outputs 961: One DPDT level relay and one SPDT malfunction relay 962: Two SPDT level relays and one SPDT malfunction relay Relay Ratings SPDT: 5 amps @ 120 VAC, 250 VAC, and 30 VDC, 0.15 amp @ 125 VDC Fail-safe Selectable for high or low level Power Consumption 961/962 Less than 3 watts Ambient Temperature MODEL 961/962 WITH CURRENT SHIFT OUTPUT Supply Voltage Current Shift Output 961: 8 mA normal operation, 16 mA level alarm (±1 mA) 962: 8 mA normal operation, 12 mA lower gap alarm, 16 mA upper gap alarm (±1 mA)...

PERFORMANCE SPECIFICATIONS Repeatability Response Time Time Delay Variable 0.5 – 10 seconds on rising and falling levels Continuously verifies operation of electronics, transducer, piezoelectric crystals, and electrical noise Manual: Push button verifies operation of electronics, transducer, and piezoelectric crystals Shock Class Vibration Class Electromagnetic Compatibility PHYSICAL SPECIFICATIONS Housing Material Cast aluminum A356-T6, cast 316 stainless steel, or deep drawn 304 stainless steel (hygienic housing) Cable Entry Dual 3⁄4" NPT, or M20 connections (one end is plugged) Gross Weight...

DIMENSIONAL SPECIFICATIONS INCHES (MM) 4.00 (102) Actuation length for NPT connection Model 961/962 with Remote Electronics Remote Transducer with NPT Connection Actuation length B Actuation length A Model 962 with NPT Connection Model 962 with ASME Flang

MODEL NUMBER 961/962 ELECTRONICS 1 2 3 | BASIC MODEL NUMBER 9 6 1 Single-point electronics Dual-point electronics 4 | INPUT POWER 2 100 to 265 VAC line-powered 5 | OUTPUT SIGNAL 0 mA current shift (available with Input Power code 5) 5-amp gold flash relays (available with Input Power codes 2 or 7) 7 | HOUSING COVER 0 Standard housing cover Glass window cover (available with Electronics Housing codes 0 or 1) 8 | MOUNTING 0 Remote (requires connecting cable) Integral / High Vibration (available with Output Signal code D) Remote / High Vibration (available with Output Signal code D) 9 | AGENCY APPROVAL...

MODEL NUMBER 961 SINGLE POINT TRANSDUCER 2 | TRANSDUCER UNIT OF MEASURE A English (length in inches) Metric (length in centimeters) 4 | MATERIALS OF CONSTRUCTION A 316/316L stainless steel, NACE construction 316/316L stainless steel, ASME B31.1 & B31.3 construction – CRN Available 316/316L stainless steel, ASME B31.1, B31.3 & NACE construction – CRN Available CPVC (use only with Process Connection codes 11, 23, 33, 43, BA, CA, DA) – CRN Available Kynar (use only with Process Connection codes 11, 23, 33, 43, BA, CA, DA) – CRN Available ➀ ➀ Flanged Kynar transducers have Kynar faced 316 stainless...