Gauge Pressure Transmitter


The LD290 series is the cost-effective alternative for gauge pressure measurement. This lightweight model eliminates the need for a mounting bracket and bracket in many applications.


  • LD290 - Smar0 ~ 0.5 inH20 up to 0 ~ 3600 psi
  • Accuracy of ± 0.075%
  • 40:1 rangeability
  • Wet Parts in 316L Stainless Steel and Hastelloy
  • Fully Digital; Including Sensor, Electronics and Communication (Except LD290)
  • LCD Digital Display
  • Weatherproof, Explosion-Proof and Intrinsically Safe
  • self-diagnosis
  • Four Technology Options


LD290 - 4 a 20 mA

  • 100 ms output current update time;
  • High performance math coprocessor;
  • Sensor and digital electronics;
  • Weatherproof, explosion-proof and intrinsically safe;
  • FMEDA (Failure Modes Analysis, Effects and Diagnostics);
  • MTBF (Mean Time Between Failures) of 239 years;
  • MTTR (Mean Time to Repair) of 18 minutes;
  • MTTF (Mean Expected Time to Fail) of 239 years;
  • Applicable in safe areas requiring SIL (Safety Integrity Level);
  • Hardware write protection;
  • Designed and built in accordance with ISO 9001.


LD291 - HART® - 4 a 20 mA

  • Output current update time in 100 ms;
  • Output current resolution of 0.75 ?A/bit;
  • It has a high performance math coprocessor;
  • FMEDA Analysis (Failure Mode Analysis, Effects and Diagnostics);
  • MTTR (Mean Time to Repair) of 18 minutes;
  • MTTF (Mean Expected Time to Fail) of 239 years;
  • MTBF (Mean Time Between Failures) of 239 years;
  • Applicable in safe areas requiring SIL (Safety Integrity Level);
  • Hardware write protection;
  • Easy upgrade to FOUNDATIONTM fieldbus technology and PROFIBUS PA
  • Designed and built in accordance with ISO 9001.


LD292 - FOUNDATION fieldbus

  • Instantiation and deletion of function blocks;
  • Network master capability;
  • Easy upgrade to HART® and PROFIBUS PA technology.



  • Uses analog input function;
  • Easy firmware upgrade (via Flash Memory Interface);
  • Easy upgrade to FOUNDATION™ fieldbus technology and HART®.

Types of Transmitters:

  • Gauge Pressure - LD290:
    Model LD290 is a transmitter with pure 4-20 mA output. Although it has only analog output, its microprocessor electronic circuit allows interchange with SMAR capacitive sensors.
  • Gauge Pressure - LD291, LD292 and LD293:
    Models LD291, LD292 and LD293 offer digital communication based on HART®, FOUNDATION™ fieldbus and PROFIBUS PA protocols, respectively, simplifying calibration and providing remote diagnostics. They have a microprocessor electronic circuit, which allows an interchange with SMAR capacitive sensors.

Applications with Manifold Valves

SMAR Manifold Valves provide all the necessary safety for field maintenance operations of LD290 Series transmitters. They work with pressures up to 6,000 psi, are easy to handle and are lighter than many models found on the market. Resistance and tightness tests carried out on all parts, including the option integrated into the transmitter. For more information, see the SMAR Manifold Valves catalogue.

Applications with Sanitary Transmitters

Models LD290S, LD291S, LD292S and LD293S were specially designed for food applications, among others, where sanitary connections are required. Tri-clamp and threaded connections allow for quick and easy maintenance. Sanitary connections comply with 3A-7403 for food applications. For more information, see the SMAR Manifold Valves catalogue.

  • LD290
  • LD291
  • LD292
  • LD293

Zero, span and damping adjustment via magnetic tool (only if used with the display).

The LD291 with HART® protocol can be configured by:

  • HI331 BLUETOOTH for android devices (App DEVCODROID) and Windows PC;
  • Third-party configuration tools based on DD (Device Description) or DTM (Device Type Manager).
  • For LD291 diagnostics management, AssetView ensures continuous information monitoring.

The LD292 uses the H1 communication protocol, an open technology that allows any H1-enabled configuration tool to configure this equipment.

Syscon (System Configurator Tool) is software used to configure, operate and maintain field equipment. Syscon provides efficient and user-friendly interaction using Windows Server 2003, Windows Server 2008, Windows Server 2012, Windows Server 2016, Windows 2000, Windows XP, Windows Vista (32/64), Windows 7 (32/64), Windows 8 (32/64) y Windows 10 (32/64). Configuration tools such as AMS™, FieldCare™ and HHT375 can configure LD292 devices. DD (Device Description) and CF (Capability File) files can be downloaded from the SMAR website or the Fieldbus Foundation™. LD292 supports complex configuration strategies due to high capacity and variety of function blocks instantiable.

Seventeen types of function blocks are available and up to twenty of them can operate simultaneously. Fieldbus technology enables AssetView to access status and diagnostic information. In this way, maintenance procedures become more effective, providing greater safety and plant availability.

The LD293 was designed to use the PROFIBUS PA protocol and can be configured using SMAR ProfibusView or Simatic PDM and the FDT (Field Device Tool) and DTM (Device Type Manager) tool concepts, such as FieldCare™ and PACTware™. It can also be configured by any PROFIBUS system using the GSD file.

PROFIBUS PA also provides quality and diagnostic information, improving plant management and maintenance.

The EDDL and DTM files are available on the SMAR website.

According to profile 3.0.

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