Absolute Pressure Transmitters

Working Principle of an Absolute Pressure Transmitter

These transmitters work on the principle of absolute zero and not relative pressure. They are not influenced by external atmospheric changes such as altitude or air pressure fluctuations. Since they have no connection with the external system, they do not need an exhaust or a release node. They convert mechanical energy or pressure into an electrical signal. So, here the pressure measured is relative to the vacuum created in the system.

An absolute pressure sensor inside these transmitters detects pressure relative to a sealed vacuum reference chamber rather than atmospheric pressure, ensuring measurement consistency regardless of altitude, weather, or ambient air pressure changes.

Recommended Absolute Pressure Transmitter Models

The Transmitter Shop (TTS) offers a variety of Rosemount absolute pressure transmitter models. Here are some models of Rosemount absolute pressure transmitters:

• Rosemount 3051ST Pressure Transmitters:

  These are designed for absolute and gage pressure measurements. They facilitate a direct connection between the transmitter and the processor. These transmitters are cost effective and yet offer a high level of accuracy.

• Rosemount 2088 Pressure Transmitters

  These user-friendly and high-performance pressure transmitters come with in-built configuration buttons and easy-to-use menus. They use the piezoresistive sensor technology for absolute and gage pressure measurements, and can be availed with remote seals and manifold.

• Rosemount 2051T Pressure Transmitters:

  This transmitter has a local operator interface (LOI), which reduces the number of tools required for commissioning. We ship it to you in a ready-to-be-installed state.

Common Beneficial Features of Absolute Pressure Transmitters

Each Rosemount absolute pressure transmitter has some unique as well as common features. Here are some common beneficial features of Rosemount absolute pressure transmitters:

• Most Rosemount models are available in absolute pressure transmitter range from 0 to 10000 psi for pressure and level solutions.
• Most of the Rosemount models are designed to measure either absolute or gage pressure depending upon your application requirement.
• For most models, the user can select the output, which is either linear or square root. They offer a digital signal output based on the HART protocol.
• They have a rugged design, and the materials of construction comprise carbon steel, stainless steel, alloy C-276, or Hastelloy.
• We offer smart pressure transmitters which can be directly mounted onto the impulse line without the need for any additional brackets.
• They are equipped with smart communication systems, a leak-checked integral manifold, and external push button zero and span capabilities.
• They start up fast, and are compact and lightweight.
• They are certified for use in hazardous environments, boilers, and so on.
• They have an absolute pressure sensor with remote seals.
• Each unit integrates an absolute pressure sensor with remote seals, ensuring the sensing element remains isolated from process media while maintaining accurate vacuum-referenced measurement.

Absolute Pressure Sensor vs Absolute Pressure Transmitter: What is the Difference?

An absolute pressure sensor is the core sensing element that detects pressure relative to a perfect vacuum (absolute zero). An absolute pressure transmitter integrates this sensor with signal conditioning electronics and outputs a standardised signal such as 4-20 mA or HART for use in process control systems. In industrial applications, the terms are often used interchangeably, but technically the transmitter is the complete field instrument while the sensor is the measurement element inside it. All Rosemount absolute pressure transmitters available at TTS incorporate a high-performance absolute pressure sensor designed for long-term stability and accuracy in demanding process environments.

Applications of Absolute Pressure Transmitters

These transmitters are used to measure the level, temperature, pressure, and flow rate of fluids and gases in closed systems, across industries. Here are some industries where absolute pressure transmitters and absolute pressure sensors are used:

• Pharmaceuticals
• Food & beverages
• Oil & gas
• Petrochemical
• Chemicals
• Science research
• Vacuum processing
• Laboratory and testing systems
• Gas storage and delivery
• HVAC and refrigeration
• Semiconductor manufacturing
• Distillation and evaporation systems

If you are specifically looking for a Rosemount absolute pressure transmitter model for your application, The Transmitter Shop has it for sure. If you are not sure which one is right for you, we are more than happy to help you make a decision. Do go through the collection of absolute pressure transmitters listed on our website. If you have any specific queries about the Rosemount absolute pressure transmitters, you can contact us on phone or email.

Need to Calibrate Your Absolute Pressure Transmitter?

If your absolute pressure transmitter is showing inconsistent readings, has been operating for an extended period, or requires verification after maintenance or process changes, professional calibration can help confirm its measurement performance. The Transmitter Shop (TTS) provides absolute pressure transmitter calibration services using SI-traceable standards. Contact TTS to discuss your transmitter calibration requirements and determine the appropriate service for your application.

FAQ's About Absolute Pressure Transmitters

What Are the Benefits of Absolute Pressure Transmitters?

Absolute pressure transmitters provide a stable pressure reference based on a vacuum rather than local atmospheric pressure. This is particularly valuable when pressure must be monitored accurately despite changes in weather, elevation, or atmospheric conditions.

What Is the Difference Between Absolute Pressure and Gauge Pressure?

Absolute pressure is referenced to a perfect vacuum, while gauge pressure is referenced to the surrounding atmospheric pressure. Gauge pressure therefore changes with atmospheric conditions, while an absolute-pressure measurement maintains a fixed vacuum reference.

Why Does an Absolute Pressure Transmitter Read Approximately 14.7 PSIA at Atmospheric Pressure?

Because an absolute pressure transmitter uses a perfect vacuum as its zero reference. At standard sea-level atmospheric conditions, atmospheric pressure is approximately 14.7 PSIA or 101.3 kPa absolute. A gauge transmitter would read approximately zero at the same condition because its reference is atmospheric pressure.

Can I Use a Gauge Pressure Transmitter for an Absolute Pressure Measurement?

A gauge pressure transmitter is not a direct substitute when the process requires a fixed vacuum reference. Because gauge pressure is referenced to local atmospheric pressure, changes in atmospheric pressure can affect the reading. For applications requiring actual pressure relative to vacuum, an absolute pressure transmitter is the appropriate measurement type.

How Is an Absolute Pressure Transmitter Calibrated?

Calibration requires a known absolute pressure reference rather than simply venting the transmitter to atmosphere. The calibration equipment must therefore be capable of generating or referencing the required absolute pressure range. This differs from a gauge transmitter, which can be checked against atmospheric pressure for its zero reference.