Pressure Sensors

In MICROSENSOR, the pressure sensor is the piezoresistive core sensing element. It is an isolated, oil-filled sensing element designed to convert mechanical pressure into a measurable electrical signal. Unlike finished pressure transmitters with external housings and displays, a sensor core is the fundamental, high-precision component designed to be integrated into your own specialized systems or equipment. These industrial-grade elements are ruggedly packaged—typically housed in stainless steel to ensure compatibility with various corrosive gases and liquids. 

Piezoresistive Pressure Sensors Working Principle

• Piezoresistive Effect

Piezoresistive pressure sensors operate based on the piezoresistive effect. When pressure is applied to the diaphragm, it deforms, causing mechanical strain in the piezoresistive elements. The strain leads to a change in the resistance of the piezoresistive elements. This change in resistance is proportional to the applied pressure.

• Wheatstone Bridge Configuration

The Wheatstone bridge circuit measures the change in resistance. The Wheatstone bridge consists of four resistors, with the piezoresistive elements acting as two of the resistors. When pressure is applied, the resistance change in the piezoresistive elements unbalances the bridge circuit.

• Signal Conversion

The unbalanced bridge produces a small voltage signal (typically in the range of millivolts, mV). This raw analog signal is directly proportional to the amount of pressure applied. In a finished pressure transmitter, this millivolt signal is converted to a standard industrial output like 4-20mA or 0.5-4.5V.

Pressure Sensor Advantages of MICROSENSOR 

• Automation Manufacturing Equipment

The automated production line in key processes such as bonding, diaphragm welding, oil filling, sealing, and compensation ensures stability and consistency and meets customers'order needs in different batches.

• Mature Production Technology

The level of manufacturing technology has a crucial impact on product performance. As a pressure sensor element manufacturer with decades of production experience, Micro Sensor ensures the accuracy and reliability of pressure elements through the Pressure Cycling and Aging, Automatic Compensation Test System, and Laser Trimming.

Micro Sensor has its piezoresistive pressure sensor manufacturing site, realizing digitization, automation, and flexibility, and manufacturing series products, including customized MPM280 Series, high-performance MPM281 Series, and general MPM288 Series, which conform to the highest quality criteria. By choosing our OEM pressure sensor elements, you gain a strategic supply partner committed to reducing your R&D cycles and enhancing the competitive edge of your product portfolios.

How to Choose A Suitable Pressure Sensor?

Choosing a suitable pressure sensor requires determining the following factors:

• Pressure Type: Pressure type can be divided into gauge pressure (G), sealed gauge pressure (SG), absolute pressure (A), and differential pressure (D). The main difference is that different pressure points are used as reference points for the sensor's zero point. Application requirements and environmental conditions are important considered factors.

• Pressure Range: Make sure the pressure range provided covers the pressures likely to occur in the working application. It's suggested that the normal working pressure should be near the middle of the selected measurement range. On the one hand, this can maximize accuracy and reduce errors. On the other hand, possible accidental pressure changes will not cause the sensing element to be overloaded and damaged.

• Size: The installation environment determines the size of pressure elements, such pipes diameter, equipment size, etc. If you cannot determine the size of the installation space, it will cause installation problems for the pressure element. Micro Sensor provides ф19mm, ф17mm, ф15mm, ф12.6mm and other optional diameters. The height is also optional for different applications, such as 6.5mm and 11.5mm. Customized sizes are also available upon customer request.

• Operating Temperature: The working temperature range refers to the pressure sensor that can work without failure at a certain temperature. Some pressure elements' operating temperature range can reach -40~125℃.

• Special Working Conditions: Special working conditions are mainly the requirements of the installation environment. If there are factors such as high temperature, high pressure, corrosive media in the environment, you need to choose a pressure sensor with corresponding materials and protective measures. According to special working conditions, Micro Sensor will analyze the actual needs of customers and provide the most suitable customized product solutions.

Frequently Asked Questions

What is the difference between an OEM pressure sensor element and a pressure transmitter?

A: At MICROSENSOR, an OEM pressure sensor element is the encapsulated sensing component, typically a stainless steel capsule, that provides a millivolt (mV) output. It delivers long-term stability for a range of OEM applications. A pressure transmitter is a finished instrument that includes the sensor element plus conditioning electronics to provide standard industrial outputs like 4-20mA or 0-10V, housed in a complete protective casing.

Do your OEM pressure capsules include temperature compensation?

A: Our high-precision pressure capsules come with integrated temperature compensation circuits. This ensures accuracy across a wide temperature range, typically from -20°C to +85°C, minimizing thermal zero and span shifts.

Can these pressure-sensing elements be used with corrosive media?

A: Yes. For applications involving harsh chemicals or seawater, we offer corrosion-resistant materials such as Tantalum, Hastelloy C, or specialized coatings. Our standard 316L stainless steel isolated diaphragms are suitable for most non-corrosive liquids and gases.

Still Have Questions? Our application engineers are ready to assist you. Contact us for a deep dive into your project specifications.