Differential Pressure Transmitters


Differential pressure measurement is an important requirement across industries. Differential pressure is the difference between any two measured pressures, and this measurement is performed using differential pressure transmitters. These transmitters always make a comparison between the low side and high side pressures. They convert these pressure measurements into a 1-5Vdc output or 4-20 mA signal. These signals serve as input to a recorder, a controller, or any similar device.

The Transmitter Shop (TTS) offers differential pressure (DP) transmitters from Emerson and other industry-leading brands. Rosemount differential pressure transmitters are used for sensing the level of fluid in condensers to acquire quantitative data of performance in the process, and so on. Over the years, we have helped clients improve their process efficiencies by delivering them new, surplus, and reconditioned differential pressure transmitters at discount prices.

  1. IDP10
  2. 3051C
  3. 1151
  4. 3051S
  5. 2051C

Working Principle of Differential Pressure Transmitters

Differential pressure transmitters comprise a sensor module, an electronic housing, and process flanges. The sensor module features two sealed fluid systems, a pressure sensor, two isolation diaphragms, and an overpressure diaphragm. The electronic housing features an amplifier board and wiring terminals. The flanges serve as the outer wall of input chambers and they provide necessary LO and HI port connections.

In the sensor module, the electronic pressure sensor is positioned on the micro diaphragm, which creates a barrier between the two fluid systems. Of these two, one system corresponds to the LO pressure input and other to the HI pressure input. The isolation diaphragm is named so because it helps isolate the fluid system from the input pressure. These isolation diaphragms will retract or compress whenever a differential pressure is applied across the LO and HI ports. This retraction or compression usually occurs in response to the pressure applied. There are situations when the pressure applied across LO and HI ports may exceed the highest limits specified. In this condition, an overpressure diaphragm takes the control of the system, and stops overpressure from affecting the sensor.
The movement of isolation diaphragm under differential pressure gives valuable information on the variables in sealed fluid systems, which are being detected by the sensor.

Types of Rosemount Differential Pressure Transmitters Provided by TTS

At TTS, we help clients choose from the following differential pressure transmitters of Rosemount brand:

  • 3051S: The Rosemount 3051 pressure transmitter has set industry standards for pressure transmitters. These Rosemount DP transmitters will enable you to gain more control over your process. This pressure transmitter is available in differential, gauge, and absolute pressure configurations. 3051S is a differential pressure transmitter, which is widely used in service industries for flow measurement due to the following benefits that they offer:
    • They are offered as pre-assembled to primary elements that ensure easy installation.
    • This pressure transmitter features an all-welded hermetic SST SuperModule™ platform and delivers a 15-year limited warranty and 15-year stability.
    • They are leak-tested as well as calibrated to reduce leak points.
    • Rosemount 3051 differential pressure transmitters feature local operator interface with easy-to-offer menus, as well as in-built configuration buttons
    • They assure 200:1 range down that produces reliable measurements and flexibility.
  • 2051: The Rosemount 2051 transmitter assures reliable differential pressure flow measurements. The following are a few beneficial features of these pressure transmitters:
    • These pressure transmitters can perform up to 0.05% of span accuracy and assure range down up to 100:1.
    • They are ideal for differential pressure measurement up to 2000 psi (137,9 bar).
    • The transmitter features a local operator interface that features built-in configuration buttons and easy-to-use menus. The interface enables easy commissioning.
    • Rosemount 2051 pressure transmitter features a coplanar platform that enables integration of manifolds, primary elements, and remote seal solutions.
  • 1151: This transmitter from Rosemount is known for its longevity and field-proven reliability. Rosemount 1151 transmitter is available in differential, absolute, and gage pressure measurement configurations with integrated solutions for level, pressure, and flow measurements. This Rosemount differential pressure transmitter has gained immense popularity over the last 35 years owing to its following features:
    • These DP transmitters offer excellent performance in the harshest work environments.
    • Through ongoing efforts for improvement, the reference accuracy of ±0.075% has been achieved.
    • The smart electronics in this Rosemount DP transmitter offer the rangeability of 50:1, which helps reduce the number of transmitters to be specified, procured, as well as stored in inventory.
    • These DP transmitters are also available in high-pressure models, which can withstand static inline pressures up to 4500 psi.

Applications of Differential Pressure Transmitters

Differential pressure transmitters are used for measuring the following:

  • Density: When used for measuring density, these transmitters measure the pressure difference between two points of the vertical plane. This difference in pressure helps get the exact density value. The density is always proportional to the pressure difference.
  • Flow: Differential pressure transmitters are used for flow measurement across venturi tubes, orifice plates, pitot tubes, as well as other flow applications. Differential pressure transmitters for flow measurement take advantage of the square law relationship that exists between the flowrate and differential pressure. So, when buying differential pressure transmitters for flow measurement, always consider the following factors:
    • Type of fluid
    • Temperature
    • Line pressure
    • Flow turndown
  • Level: In many industries, DP transmitters are used for level measurement. These devices are used in sealed tanks. They compare the pressure at the top and bottom of the tank. The shape of the tank is one of the important considerations to be made when buying these devices for level measurement. Although most transmitters can compensate for regular shaped and standard tanks, they may not be ideal for irregular shaped tanks. Hence, check on this fact, if you are considering irregularly shaped tanks.
  • Viscosity: When used for viscosity measurement, the differential pressure transmitter takes into account the differential pressure on the orifice plate. During the process, a fluid is pumped through an orifice plate at a fixed rate using a pump that works on a positive displacement principle at a specific pressure and temperature.

Industrial Uses of Differential Pressure Transmitters

We have been delivering Rosemount differential pressure transmitters to our clients across industries such as:

We understand the importance of delivering quality pressure transmitters and accessories. This is why we only stock products from industry-leading brands. Differential pressure transmitters play a key role in the process results, and we cannot disappoint our customers who approach us with key parameters such as safety and productivity in mind. Owing to such a vast selection of differential pressure transmitters on sale, it is quite obvious to get confused. To ease the selection, you can get in touch with our team of experts today. Having spent more than three decades in the industry, they perfectly understand your needs and requirements. For more information on any of these differential pressure transmitters or other transmitters, please contact our team today.