Whether it is a hydraulic system or machinery, oil or liquid pressure determines the overall performance. Operators have to monitor the pressure and avoid the burden on the system.
Pressure Transmitters are those devices that play a crucial measurement in such machinery and come in different types and mechanisms.
Do you want to know various types of pressure transmitters? Today, we will elaborate on the crucial types and understand how they work. Let’s have a detailed discussion on the types of pressure transmitters!
Fundamentals of Pressure Transmitters
Pressure Transmitters are devices that help sense the pressure changes and give an electrical signal, such as 4–20 mA, 0–10 V, or digital communication signals.
You can’t directly interpret the measurements into the pressure changes. Therefore, the conversion to the electrical signal helps translate the message and get the reading on the display screen.
How do Pressure Transmitters work?
Pressure Transmitters have a simple working mechanism based on the fluid pressure applied to the diaphragm of the measuring tool.
For example, here are a few steps to define the exact working mechanisms of the pressure transmitters.
- Pressure sensing elements. Each pressure transmitter has a sensing element, such as a diaphragm.
- Pressure changes. The sensing element deforms slightly depending on the pressure.
- Electrical signal. Pressure deformation impacts the diaphragm and causes an electrical signal that undergoes translation.
- Electronics inside the transmitter process and standardize this signal for monitoring and control systems.
The integration of components and combined functionality can help get accurate results.
Types of Pressure Transmitters
Types of pressure transmitters are comprehensive. It depends on your choices and which pressure transmitter type you want to select.
We have the list of key types of pressure transmitters.
Absolute Pressure Transmitters
An absolute pressure transmitter measures the pressure relative to zero. It uses a sealed chamber and notes the pressure changes relevant to the vacuum.
It is pretty impactful for several applications and systems. For example:
- Altitude measurement in aerospace and aviation.
- Monitoring vacuum systems.
- Measuring atmospheric pressure in weather stations
The pros include:
- Highly accurate for absolute measurements.
- Stable against atmospheric variations
The cons are:
- Can’t take measurements if the vacuum system is not available.
Gauge Pressure Transmitters
Instead of a vacuum system with an absolute zero reference, a gauge pressure sensor measures the pressure relative to the atmospheric pressure. It has a sensing element exposed to the external environment and provides instant measurements after comparing it with the environmental pressure.
The top applications of such a system include:
- Tire pressure monitoring.
- Hydraulic and pneumatic system monitoring.
- Industrial compressors and pumps
The pros include:
- Widely used and cost-effective in the vehicle system.
- Practical for everyday industrial and consumer needs.
The cons are:
- Not suitable when you need absolute pressure measurement.
Differential pressure transmitters
The name of the tool depicts its working mechanism. This pressure transmitter type measures the pressure between two different points. For example, the element has a low-pressure point at one side and a high-pressure point at another. It measures the difference between them and gives accurate readings.
Such pressure transmitters are also helpful for the following applications.
- Orifice plates, Venturi tubes, or Pitot tubes.
- Level measurement in pressurized tanks.
- Monitoring filter or strainer clogging by measuring inlet vs. outlet pressure
The pros include:
- Highly versatile for flow, level, and filter applications.
- High accuracy and reliability.
The cons are:
- The installation process is a little complex compared to the other pressure transmitters.
Sealed Pressure Transmitters
A sealed pressure sensor is more like a gauge pressure sensor with the already given pressure to compare with. For example, a sealed pressure sensor has a 1ATM reference pressure, which is fixed. The measurement pressure compares it with this value and gives the pressure readings.
Such pressure sensors are ideal for the marine and aerospace industry.
- Deep-sea exploration and underwater equipment.
- Harsh chemical environments where exposure to air could damage the sensor.
- High-altitude aircraft systems.
The pros include:
- Resistant to environmental changes.
- Ideal for rugged applications
The cons are:
- If the environmental pressure varies significantly, they might give inaccurate values and cause issues.
Multivariable Pressure Transmitters
A multivariable pressure transmitter is a unique type that provides a range of applications. For example, it simultaneously senses the pressure, temperature, and differential pressure. Because of several sensing elements, different factor measurements are no longer a trouble for this tool.
- Flow measurement with compensation for temperature and pressure changes.
- Advanced process monitoring in oil, gas, and chemical industries.
The pros include:
- It does various tasks with a single device.
- Saves costs and provides accuracy.
The cons are:
- The upfront cost is high, as you do multiple tasks with one tool.
Hydrostatic Pressure Transmitters
A hydrostatic pressure transmitter is a device that measures the pressure of the liquid. It merges into the liquid and measures the pressure changes. However, the deeper submergence means a higher pressure exertion and measurement.
Hydrostatic pressure Transmitters provide a range of applications, such as:
- Water treatment plants.
- Storage tanks.
- Dams and reservoirs.
The pros include:
- Efficient and straightforward to use
- Cost-effective for tank and water applications
The cons are:
- It is not suitable for highly corrosive water or liquids. Use it with proper caution and features.
Sanitary Pressure Transmitters
Sanitary pressure sensors are designed to measure the pressure for sanitation purposes in various liquid or beverage industries. Such pressure transmitters use hygienic materials and minimize the bacterial contamination of the stainless steel housing.
The key applications of such press transmitters include:
- Dairy production.
- Brewing and beverage bottling.
- Pharmaceutical manufacturing
The pros include:
- Designed to meet FDA and hygienic standards.
- Easy to clean (CIP/SIP compatible)
The cons are:
- They are more expensive because of the sanitary goals that elevate the overall costs.
Smart Pressure Transmitters
Smart pressure transmitter types are the advanced solutions that come with better accuracy and newer communication protocols, such as HART, Foundation Fieldbus, or Profibus. They provide a digital signal and are often connected with the cloud system to manage the settings remotely.
Here are a few use cases of such pressure sensors.
- Advanced industrial automation
- Remote monitoring in oil & gas pipelines.
- Chemical processing plants
The pros include:
- High accuracy and self-diagnostics.
- Can be configured remotely.
The cons are:
- Because of intelligent control and remote configuration, setup and installation costs and upfront costs are higher.
Low-Pressure Transmitters
As the name highlights, these pressure transmitters are ideal for measuring the pressure at very low pressure conditions, such as vacuum.
The key applications include:
- Cleanroom monitoring.
- HVAC systems.
- Leak detection.
The pros include:
- Sensitive to small pressure changes.
- Useful in precision industries.
The cons are:
- It has a limited pressure range compared to the competitor tools.
Points to look for when choosing a pressure transmitter
Choosing a pressure transmitter is a no-brainer. What you should do is to select the right type and quality. Here are a few tips to select the right pressure transmitter type.
Define pressure range
The pressure range should be higher than the maximum pressure measurements if you want the safety of the tools. For example, you are working on a device with a 100 bar pressure and spikes to 120 bar. For safety purposes, you should get pressure transmitters that offer a 140 bar or more for pressure safety.
It can handle surges and provides better measurement accuracy.
Prioritize accuracy
Wrong press measurements are a headache. A tool with an error of 0.5% is still acceptable. However, lower errors mean better accuracy.
You should prefer those tools that offer accuracy and a better measurement range.
Match material to process
Check the medium and then go for the material. Incompatible media and applications can cause hindrances in the measurements.
For example:
- For corrosive fluids, stainless steel 316L, Hastelloy, or titanium diaphragms are the best selections.
- If the application is hygienic (food, dairy, pharma), select a sanitary-grade transmitter with flush diaphragms for easy cleaning.
- In high-temperature systems, check compatibility with cooling elements or remote diaphragm seals.
Choose the output signal.
Different types of output signals help measure. You should consider the following types.
- Traditional analog outputs like 4–20 mA
- Voltage outputs (0–10 V) are helpful.
- Digital protocols like HART, Profibus, or Foundation Fieldbus
Evaluate installation and maintenance.
Installation should be simple and of high quality. Moreover, you might not want easy maintenance.
- Consider the mounting types, such as threaded, flange, or sanitary connections
- There should be built-in surge protection, overpressure limits, and fail-safe modes for added safety.
- You should grab the pressure transmitter with ATEX, IECEx, or FM explosion-proof certifications to avoid mishaps.
Conclusion
Pressure Transmitters are the backbone of the machinery and other tools. They are unsung heroes who provide an assessment of the pressure and give ideas about accuracy. However, their selection is crucial because you can’t compromise on the compatibility and quality.
Where do you get the premium quality pressure transmitter sensor types? Sendo-sensor is the best place for all the solutions. We have a range of pressure transmitter types and provide the most affordable costs with premium solutions. Check out our latest pressure transmitter products today!