Out in Front: September 12, 1996

Measurement Specialties Inc ma-chines the body of each of its MSP 300 pressure sensors and MSP 310 pressure/temperature sensors from a single piece of metal. The sensors cost $40 (OEM), despite several benefits of the construction--extreme ruggedness, a life of 10⁸ pressure cycles, freedom from failure-prone seals, complete isolation of the sensing elements from the medium whose pressure the sensor is monitoring, and the ability to withstand (without damage) the greater of five times the rated pressure or 20,000 psi.

Each pressure-sensing element comprises a group of proprietary microfused, micromachined silicon strain gauges. The MSP 310's temperature sensor is an IC, which measures temperatures over the full ­20 to +85°C operating range. (The MSP 300's operating-temperature range is the same.) The most sensitive units measure pressures of 0 to 100 psi; the least sensitive handle 0 to 10,000 psi. You can choose output levels of 0 to 100 mV, 1 to 5V, or 4 to 20 mA. Errors from nonlinearity, hysteresis, and imperfect repeatability total less than 1% of full-scale output. Long-term instability is less than 0.25% of full-scale output. The 2.2-in.-long units weigh 3 oz and connect to the pressurized medium via a ¼-in., National Pipe Thread port. The vendor supplies other ports on request.

—by Dan Strassberg

Measurement Specialties Inc, Fairfield, NJ. (201) 808-1819, fax (201) 808-1787, sensors@mssusa.com.