SMAR LD291 Transmitter Assembly

Core Performance & Industrial Application

The SMAR LD291 is a microprocessor-based gauge pressure transmitter with HART digital communication, mounted here on an extended-diaphragm seal flange assembly.

Two-wire 4-20 mA output per NAMUR NE43 superimposes HART digital signal for remote calibration and diagnostics.

On-unit label: sensor model LS, calibrated range -14.7 to 3000 PSI, max working pressure 4500 PSI (310 bar), silicone oil fill.

Automatic temperature compensation corrects sensor drift; accuracy ±0.075% of calibrated span, 40:1 rangeability.

The diaphragm seal isolates the process and transmits pressure through the filled capillary/stem to the sensor for viscous, corrosive or tank-mounted service.

Technical Specifications

▶ Product type: Gauge pressure transmitter + diaphragm seal assembly

▶ Brand: SMAR (Novo SMAR)

▶ Model: LD291 (sensor code LS; seal flange SMAR B16.5)

▶ Output: 2-wire 4-20 mA HART®; NAMUR NE43

▶ Supply: 12-45 VDC loop power

▶ Range: -14.7 to 3000 PSI (label); capacitive family 0-25 MPa (3600 psi)

▶ Max working pressure: 4500 PSI (310 bar); fill silicone oil

▶ Accuracy: ±0.075% calibrated span; rangeability 40:1; SIL capable

▶ Ambient: -40℃ ~ +85℃; process -40℃ ~ +100℃ silicone; humidity 0-100% RH

▶ Mounting: ANSI B16.5 stainless flange, extended stem seal

▶ Feature: HART remote setup, LCD diagnostics, single interchangeable board

▶ Note: Full order/tag code and seal diaphragm material confirmed from nameplate before ordering

▶ Country of origin: Brazil

▶ Compliance: CE, UL, SIL certification

Industry Applications

Applied in tank level, viscous/corrosive process pressure and seal-mounted transmitter spare replacement.

Note: Confirm full tag code, range span, diaphragm material and flange rating against nameplate before ordering