Kynar helps level switch resist corrosive media

Citation

(2001), "Kynar helps level switch resist corrosive media", Sensor Review, Vol. 21 No. 3. https://doi.org/10.1108/sr.2001.08721cad.010

Kynar helps level switch resist corrosive media

Kynar helps level switch resist corrosive mediaKeywords: Sensors, Ultrasonics

A compact, ultrasonic, two-wire level switch which can detect high or low level, across a wide range of corrosive media, is the latest addition to the range of products offered by Magnetrol International (Plate 10).

The Echotel 915W switch offers the important benefits of ultrasonic control, such as no moving parts, ease of installation, no need for calibration and rugged construction. Thanks to the superior mechanical strength and toughness of Kynar wetted parts (Kynar sensor and Kynar faced flange), the 915W switch can be specified for level control applications involving corrosive media. In addition to resisting most chemicals and solvents, Kynar provides high thermal stability and abrasion resistance.

Plate 10 Kynar helps level switch resist corrosive media

The switch operates with a standard trip amplifier. However, more importantly, as it has an output of 8 or 16mA within 4-20mA industry standard, 24 VDC loop, it can be connected directly into a PLC/DCS. This eliminates the need for additional wiring and therefore reduces installation time and capital cost.

Protected electronics and a high frequency signal ensure that the switch is unaffected by noise from surrounding equipment such as engines or pumps. Also, a continuous self-test feature checks the crystal bond, sensor and circuit, with or without liquid in the sensor.

The switch operates on a two crystal pulsed or "transmit-receive" principle which applies a high frequency electronic burst to the transmit crystal. The signal is then converted into ultrasonic sound energy and transmitted across the sensing gap toward the receiver crystal. When there is air in the gap, the high frequency sound energy will be attenuated, therefore preventing energy being received. However, when there is liquid in the gap, the sound energy will propagate across the gap and the current shift will indicate reception of the signal.

The 915W switch will operate in applications with a temperature range of –40°C to +120°C. Applications are numerous, including high/low level alarm, overfill protection, pump protection, leakage detection, filling operation monitoring, valve actuation and indicating level in sumps and tanks.

Further details and product literature is available from: Paul Sayers, Magnetrol International, Unit 1, Regent Business Centre, Jubilee Road, Burgess Hill, West Sussex RH10 9TL, UK. Tel: +44 (0)1444 871313; Fax: +44 (0)1444 871317; E-mail: sales@magnetrol.co.uk ; Web site: www.magnetrol.com