Rosemount 3051 Pressure Transmitter

Overview

The Emerson Rosemount 3051 is arguably the most widely deployed pressure transmitter in industrial history, with millions of units installed across oil & gas, chemical, power, refining, and water treatment processes worldwide. First introduced in the 1980s and continuously updated, the 3051 established the standard for the modern 4-20 mA smart transmitter by combining excellent accuracy, long-term stability, and comprehensive diagnostics in a ruggedised process-grade housing.

The 3051 product line covers differential pressure (3051C), gauge pressure (3051T), and absolute pressure (3051T and 3051CA) measurement with a coplanar flange design that accepts remote seals, manifolds, and diaphragm seals without special adaptors. HART 5 and HART 7 communication overlay digital information on the 4-20 mA loop — enabling remote configuration, diagnostics, and secondary variable transmission (static pressure, temperature) without additional wiring.

The 3051S Scalable Pressure Transmitter variant (the "S" series) uses a modular electronics/sensor design with improved 0.025% accuracy and 15-year stability specification. WirelessHART variants (3051S with WirelessHART head) allow deployment in locations where running signal cable is cost-prohibitive, transmitting at 2.4 GHz using the WirelessHART mesh network protocol (IEC 62591).

Key Features

• 0.04% reference accuracy, ±0.1%/10-year stability

  The 3051's accuracy specification of ±0.04% of calibrated span across the full operating range is among the best in class for industrial pressure transmitters. The long-term stability of ±0.1% over 10 years significantly reduces calibration frequency requirements, lowering maintenance costs in large installations.
• HART 5/7 with secondary variable output

  HART communication allows remote zero/span adjustment, diagnostic reads (sensor temperature, electronics temperature, loop current), and secondary variable transmission (static line pressure on DP units) over the same two-wire 4-20 mA loop. No additional wiring or input channels are required to monitor secondary variables.
• SIL 2 rated for safety instrumented systems

  The Rosemount 3051 is certified to SIL 2 (with achievable SIL 3 in redundant configurations) per IEC 61508, making it suitable for use in Safety Instrumented Systems (SIS) as a pressure sensing element. The SIL certification includes PFD (Probability of Failure on Demand) data for use in SIL calculation tools like EXIDA exSILentia.
• Coplanar flange with manifold compatibility

  The coplanar flange accepts direct-mount 2-valve, 3-valve, and 5-valve manifolds without adaptors, reducing leak points and enabling inline zero calibration without process isolation. Remote seal assemblies extend measurement to high-temperature, viscous, or corrosive fluids that cannot contact the process flange directly.
• Advanced diagnostics — plugged impulse line detection

  Emerson's statistical process monitoring (SPM) algorithm embedded in the 3051S monitors measurement noise patterns to detect plugged or blocked impulse lines — a common failure mode in slurry and viscous service that is invisible to standard 4-20 mA measurement. This enables condition-based maintenance rather than time-based inspection schedules.

Technical Specifications

Typical Applications

• Flow measurement (DP method): Measuring differential across orifice plates, venturi tubes, and averaging pitot tubes for gas and liquid flow
• Tank level: Differential pressure across submersible or flanged DP tap for open and closed vessel level
• Pump/compressor monitoring: Differential pressure across suction/discharge for condition monitoring and efficiency calculations
• Safety instrumented systems: SIL 2 rated overpressure detection in high-integrity protection systems (HIPS)
• Filter differential monitoring: Tracking filter clogging across heat exchangers, strainers, and particulate filters