How to choose the right pressure transmitter?

Extensive testing is necessary when developing new technology. To obtain reliable results, measuring instruments are needed that precisely meet the requirements. We show you which factors play a role in this.


Pressure range

A first clue in the search for the appropriate pressure measurement technology is the pressure range to be measured and whether a measurement of the relative or absolute pressure is intended.

Depending on the application, special features must be observed. Especially in test applications, individual measuring ranges are required that standard transmitters with pressure ranges according to ISO cannot provide. In this case, transmitters are required that map the appropriate pressure range and thus achieve the desired accuracy.

Accuracy

In engine development for racing sports cars, the smallest measured values make the difference between victory and defeat on the track. In this case, top precision is required and developers will opt for a sensor with ±0.05% FS depending on the specific application.

When considering accuracy, the factors of necessity and cost must be weighed. A good decision-making aid is usually the pressure range to be measured. If this is very wide, extraordinary accuracy is often not necessary. Those who still opt for the most precise sensor available should keep in mind that precision also has its price.

Temperature

The temperature factor is difficult to determine in some cases. Often, developers do not yet know exactly over what temperature range the pressure transmitter used must perform its service. For example, many pressure transmitters from STS are optimized for operating temperatures from -25°C to 100°C. This covers common areas of application. In principle, however, each sensor can be optimized and ordered for a particular temperature range, so that accurate results can be obtained even at temperatures as low as -40°C or as high as 150°C.

Process connection

The topic of process connection can quickly become an exclusion criterion for developers, as many companies use standardized connections. The position in which the transmitter is to be mounted can also be an important factor.

There are a variety of possible electrical connections, whether M12, DIN, MIL or others, which should also be offered by the manufacturer in different cable lengths and materials.

STS offers a wide range of connections. Due to the modular design principle of the measuring instruments, a wide range of connection options is possible.

Output signal

Equally decisive is the question of whether the measured pressure is transmitted as an analog signal or via a digital interface such as Modbus. In analog signal transmission, the pressure is converted into an analog signal that still has to be measured. With digital signal transmission, the value of the measured pressure is reproduced directly via an interface.

Space requirement

In various applications, there is little space for mounting pressure transmitters. Therefore, the size of the sensor in conjunction with the available process connections can be an important selection criterion. The type of pressure measurement technology plays a role. Piezoresistive pressure transmitters in particular are suitable for miniaturization. Therefore, STS can offer sensors with diameters of only a few millimeters.

Materials

Where is the sensor used? What environmental conditions is it exposed to? Does it come into contact with water vapor, gasoline or certain gases? The housing material is decided by the medium to which the sensor is exposed. Stainless steel housings are mostly used for test bench applications. When in contact with salt water, the choice of material falls on titanium.

Very large influence on the suitable sensor has also the sealing material. The sealing material depends on the fluid used in the pressure system. It is also essential to include the expected temperatures in the considerations.

Certifications

When used in particularly hazardous applications, for example where there is a risk of explosion, certain certifications are required that make statements about the safe operation of the instruments. The STS portfolio includes sensors such as the ATM.ECO/IS, which is approved for use in hazardous areas with FM, Fmc, IECEx, ATEX certifications.

Delivery times

Long delivery times can delay prototype testing and ultimately jeopardize product launches. Therefore, it must be clarified in advance whether the required sensors are available or what delivery times are to be expected for custom-made products.

The right pressure transmitter - Conclusion

Sensors do not necessarily meet all the required specifications. In some cases, the required sensor is not available from a manufacturer with the standardized connection options used in the company. This can result in significant additional costs. Delivery times may be delayed accordingly.

To make it as easy as possible for customers to choose the right sensor, our pressure measuring instruments are based on the modular principle. This means: Each of our pressure sensors can be calibrated for the required temperature range. Our products are also extremely flexible when it comes to process connections, sealing materials and pressure measuring ranges. Thus, due to the modular design of our measurement technology, it is possible for us to deliver pressure sensors exactly according to the required specifications within a very short time.