Level switch resists corrosive media

Citation

(2001), "Level switch resists corrosive media", Anti-Corrosion Methods and Materials, Vol. 48 No. 5. https://doi.org/10.1108/acmm.2001.12848ead.010

Level switch resists corrosive media

Level switch resists corrosive mediaKeywords: Magnetrol, Switch modules, Corrosion resistance

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 2).

The Echotel 915W switch claims the important benefits of ultrasonic control, such as no moving parts, ease-of-installation, no need for calibration and rugged construction. In Magnetrol's opinion it is thanks to the superior mechanical strength and toughness of Kynar wetted parts (Kynar sensor and Kynar faced flange) that the 915W switch can be specified for level control applications involving corrosive media. In addition to reportedly resisting most chemicals and solvents, Kynar is also said to provide high thermal stability and abrasion resistance.

Plate 2 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 is said to eliminate the need for additional wiring and therefore reduces installation time and capital cost.

Protected electronics and a high frequency signal reportedly 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, 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.

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

Details available from: Magnetrol International. Tel: +44 (0)1444 871313; Fax: +44 (0)1444 871317; E-mail: sales@magnetrol.co.uk; Web site: www.magnetrol.com