Measurements are made with a stainlesssteel rope wound on a spring-loaded spool, which turns the shaft of a rotary encoder. The rope can also be nylon coated or made of thermoplastic. The device is rated to IP67 and is designed for harsh environments. For sidewall mining, for example, the PT9150 can be equipped with a high-voltage line driver output and a resolution of 100 pulses/in. TTL and 5V line driver options are also available, as are resolutions from 10 to 250 pulses/in. The cable can exit from the front, rear, top, or bottom of the steel or aluminum enclosure.

Celesco Transducer Products Inc., 20630 Plummer St., Chatsworth, CA 91311, (800) 423-5483,