Description The PR-283 incorporates sophisticated integrated circuits and new, fused silicon monolithic cavity pressure sensors to provide a high level, fully conditioned, and temperature-compensated output and to offer up to three field selectable pressure ranges. The field selectable pressure ranges ensure that a single transducer can be configured to cover all the pressure ranges for a particular application: For example, 25, 5, and 100 PSID.  The PR-283's 17-4 PH SS monolithic pressure cavity provides media compatibility for most applications and offers a leakproof solution for today's environmentally conscious customer. Furthermore, two industry standard output versions are available for the PR-283: 4 to 20 mA two-wire loop or field selectable 0 to 5  VDC/0 to 10 VDC. A wide 12 to 40 VDC or 12 to 35 VAC unregulated supply voltage and a broad 0°F to 180°F  compensated temperature range ensure compatibility to most applications. A rugged NEMA-4 (IP-65) enclosure, gasketed cover, external mounting bracket, fully temperature-compensated NIST traceable accuracy, and a liberal two-year warranty are some of the features which make the PR-283 the industry's most reliable and economical pressure transducer. In addition, a 316 SS three-valve isolation/nulling manifold (VM-705) can be installed without any piping connection to the transducer, significantly reducing installation costs. The PR-283 sensing elements are 100% solid-state piezoresistive silicon that are strain gauge fused directly onto the 17-4 PH SS 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 offers excellent linearity, repeatability, and sensitivity, exhibits negligible hysteresis, and withstands significant overpressure without zero shift. The monolithic nature of the cavity ensures leakproof operation and enhances the overpressure and burst pressure specifications. Furthermore, the cavity design incorporates novel techniques to isolate the fused silicon sensing element from installation-related stress thereby ensuring zero integrity. The 17-4 PH SS cavity offers excellent media compatibility to most industrial and commercial applications.  The PR-283's field selectable pressure ranges were previously unheard of in the industry. With fixed pressure range transducers, the only solution to engineering error or incorrect selection was expensive field recalibration or time-consuming product exchange or replacement. Because of this, several transducers had to be kept in stock as spares to cover all the ranges for an application. With the PR-283, only a single transducer needs to be kept in stock, and it can be easily configured in the field for a desired pressure range. On VDC output units, two additional field selectable options are available: Dual outputs of 0 to 5 or 0 to 10 VDC and dual unregulated supply voltages of 12 to 35 VAC or 12 to 40 VDC. By means of a dip switch, a customer can select the desired output for the specific application. As far as supply voltage is concerned, the unit automatically configures for AC or DC. Another feature of the PR-283 is that the output is fully protected from short circuit to ground and from supply voltage mistakenly being applied to the output. The mA output transducer can function over a wide unregulated supply voltage range of 12 to 40 VDC without any affect on calibration or performance. Furthermore, it has reverse polarity protection built in; as a result, it is next to impossible to damage mA output transducers by mis-wiring. By using sophisticated low drop-out voltage regulators and CMOS integrated circuits, the mA output transducer can drive very high output impedance. In fact, with only a 12 VDC supply, the transducer can drive 400 ohms. At 40 VDC, the transducer is capable of handling up to a 3,000-ohm load. In this way, the output loop can be tied in series to multiple controllers, indicators, and other devices without degrading performance. The PR-283 incorporates a rugged NEMA-4 (IP-65) enclosure that is fully gasketed, dustproof, and splashproof. The enclosure has an external mounting bracket to facilitate field installation. A ½" (.875"/22.25mm diameter) knock-out for conduit connection is also provided, and a liquid tight cable connector is supplied for transducers that are not being hard wired. Once installed, the enclosure maintains its environmental rating and protects the electronics and sensing element from condensation, corrosive contaminants, and other environmental pollutants. The PR-283 has additional features for ease of installation including an unpluggable terminal block, easily accessible zero and span trimmers, and a conveniently located dip switch for field selection of multiple ranges. The PR-283 is available with a 316 SS three-valve isolation/nulling manifold (VM-705). The manifold assembly can be installed in the field without any piping interconnection between the transducer and manifold, which significantly reduces installation costs. 316 SS fittings and adapters are provided with each assembly to connect the transducer and manifold. The manifold assembly incorporates a rugged steel mounting bracket that is engineered to have the height and center-to-center dimensions of both units in the same plane. In this way, all the installer has to do is slip the PR-283 onto the manifold adapters and tighten two compression fittings.  The VM-705 incorporates industrial-quality, bubble tight, and multi-turn 316 SS needle valves to ensure accuracy and reliability. To form a leakproof and long-term reliable seal,  the seat is machined out of Teflon. Furthermore, the manifold assembly can withstand 400°F (204°C) and 4800 PSIG (33096 kPa) pressure without compromising performance.