Key Parameters & Specifications Model Series: 1151 (Rosemount Alphaline) Type: Absolute Pressure Transmitter Model Designation: 1151AP (Absolute Pressure variant) Pressure Range: 300 (Typically 0-30 to 0-300 psia or equivalent range) Diaphragm Material: C (Hastelloy® C-276 - corrosion-resistant alloy) Fill Fluid: A (Silicone Oil - standard industrial application fill) Process Connection: A (Standard ¼-18 NPT or equivalent) Housing Material: A (Epoxy-coated cast aluminum, standard) Electrical Connection: A (½-14 NPT conduit entry with screw terminals) Output Signal: 4-20 mA DC (two-wire) Housing Code: 115U (Specific housing configuration with options) Key Features Absolute Pressure Measurement: Measures pressure relative to perfect vacuum (0 psia), eliminating errors from barometric pressure changes Hastelloy C-276 Wetted Parts: Excellent corrosion resistance for aggressive media including acids, caustics, and harsh chemicals Range 300: Suitable for medium-range absolute pressure applications (typically up to 300 psia) Standard Fill Fluid: Silicone oil for general-purpose temperature ranges Standard Process Connection: Compatible with common piping systems Typical Applications Distillation Columns: Precise pressure control independent of atmospheric changes Vacuum Systems: Accurate vacuum measurement and control Evaporators: Pressure monitoring in evaporation processes Vapor Pressure Measurement: Reid vapor pressure and similar applications Crystallizers: Process control in crystallization operations Barometric Pressure Compensation: Applications requiring atmospheric pressure independence Specifications Details Parameter Value Accuracy Typically ±0.1% to ±0.2% of span Stability ±0.2% of URL for 12 months Temperature Limits -40°F to 250°F (-40°C to 121°C) with silicone fill Static Pressure Limit Up to 2000 psi (138 bar) typical Output 4-20 mA DC Power Supply 12-45 V DC Turn-on Time 2.3 seconds maximum Response Time 0.2 seconds typical Zero Shift ±0.25% of URL per 1000 psi (69 bar) Damping Adjustable electronically Range 300 0-30 to 0-300 psia typical span limits (0-2 to 0-20 bar a)