Description The PR-264 incorporates sophisticated integrated circuits and a new fused silicon monolithic cavity pressure sensor to not only provide a high-level, fully-conditioned, and temperature compensated output, but also to offer up to three (3) field selectable pressure ranges in one unit. The field selectable feature eliminates costly inefficiencies by providing a single unit which can be configured to cover all the pressure ranges for a particular application. For instance, 25.0, 50.0 and 100.0 psig in one unit. The stainless steel monolithic pressure cavity not only provides media compatibility for most of the applications, but also offers a leak-proof solution for today's environment conscious customers. Two industry standard output versions are available, 4-20 mA 2-wire loop or field selectable 0-5 VDC/0-10 VDC or 12-35 VAC unregulated supply voltage and a broad 0°F-180°F compensated temperature range ensures compatibility to most of the applications. Rugged NEMA 4 (IP-65) enclosure, gasketed cover, external mounting bracket, fully temperature compensated NIST traceable accuracy and a liberal five year warranty are some of the features which make the PR-264 the industry's most reliable, rugged, and economical pressure sensor. The PR-264 sensing element is a 100% solid state silicon strain gauge fused directly onto the stainless steel monolithic pressure cavity. The pressure cavity is machined out of a solid rod and does not incorporate any welds, seams, or bonds. In this way, the sensor not only offers excellent linearity, repeatability, and sensitivity, but also exhibits negligible hysteresis and withstands significant overpressure without zero shift. The monolithic nature of the cavity ensures not only leak proof operation but also enhances the overpressure and burst pressure specifications. The pressure cavity design incorporates novel techniques to isolate the fused silicon sensing element from installation related stress thereby ensuring zero integrity. The stainless steel offers excellent media compatibility to most of the industrial and commercial applications. The PR-264 incorporates sophisticated integrated circuits to not only provide a high level, fully conditioned and temperature compensated output, but also to offer field selectable flexibility which was unheard of in the industry. The PR-264 offers up to three field selectable pressure ranges in one unit. In this way, a customer does not need to know the exact pressure range prior to selection. A unit can be field configured for the desired pressure range in the field. With fixed range units, in case of engineering error or incorrect selection, the only solution is expensive field recalibration or time consuming product exchange or replacement. Similarly, numerous units have to be kept in stock as spares to cover all ranges in case of field failure. The PR-264 with the field selectable pressure range feature, eliminates above mentioned costly inefficiencies. A single unit can be configured to cover all the pressure ranges in a particular application thereby eliminating any possibility of incorrect range selection. Additionally, one unit can be kept in stock and, in the event of a failure, it can be field configured thereby eliminating the need to stock numerous fixed range units. On VDC output units, two additional field selectable options are available: dual outputs 0-5 or 0-10 VDC, and dual unregulated supply voltages 12-35 VAC or 12-40 VDC. By merely changing a dip switch, one can select the desired output for the specific application. As far as supply voltage is concerned, the unit automatically configures for AC or DC and no field selection is necessary. Another feature is that the output is fully protected from short circuit to ground, or if the supply voltage is applied by mistake to the output. Past experience demonstrates that field related wiring problems do occur. Instead of denying this fact, the protection circuit is designed in to ensure trouble-free start-up. The VDC output unit is also designed to handle low impedance circuits. In fact, the unit can drive up to 1K ohms minimum. In this way, multiple controllers, indicators, or other devices can be paralleled to the output without performance degradation. The mA output units can function over a wide unregulated supply voltage range: 12-40 VDC without any effect on calibration or performance. The unit has reverse polarity protection built in. As a result, it is next to impossible to damage the unit by mis-wiring. By using sophisticated low drop-out voltage regulators and CMOS integrated circuits, the mA output unit can drive very high output impedance. In fact, with only 12 VDC supply, the unit can drive 400 ohms. At 40 VDC, the unit is capable of handling up to a 3000 ohms load. In this way, the output loop can be tied in series to multiple controllers, indicators, and other devices without degrading the performance. The PR-264 incorporates a rugged NEMA 4 (IP-65) fully gasketed, dust proof and splash proof enclosure. The enclosure has an external mounting bracket to facilitate field installation. A ½" (.875"/22.25 mm diameter) knock-out for conduit connection is also provided. A liquid tight cable connector is also supplied if the unit is not being hard wired. Once installed, the enclosure maintains its environmental rating and protects the electronics and the sensing element from condensation, corrosive contaminants and other environmental pollutants. The unit also has additional features for ease of installation including unpluggable terminal block, easily accessible zero and span trimmers, and conveniently located dip switches for field selection.