Know-how

Gauging, calibrating and adjusting - all have something to do with accuracy and measurement. However, the way in which this is done and the accuracy that can be achieved are very different.

Data sheets from manufacturers of pressure transmitters often contain many different specifications on the subject of accuracy. In most cases, however, not all information is relevant. This article explains which information is to be taken into account and when. It also explains why long-term stable pressure transmitters are a prerequisite for cost optimization in demanding industrial applications.

A common problem in applications with water, oil, or other liquids are brief pressure peaks, which are so high that they damage the measuring cell of pressure transmitters. If pressure peaks of this kind occur, a pressure transmitter with maximum overpressure resistance, which requires a very long-term stable measuring cell and powerful electronics, must be used.

Trafag has succeeded in unifying the highly dynamic response behavior of a test bench sensor and the extreme robustness of a mobile hydraulic pressure transmitter by combining thin-film-on-steel measuring cells and an ASIC developed in-house. The Trafag ASIC TX with an innovative parallel mixed-signal structure is the key to a response behaviour at nearly unlimited speed.

The choice of the material of parts and components is almost always a compromise between performance and cost. This article outlines some considerations when choosing a suitable pressure transmitter for applications with seawater, e.g. in ballast water management systems or desalination units.

There are two major criteria to assess the corrosion resistance against salt water of a stainless steel based on material specifications: PREN Pitting Resistance Equivalent Number and CPT Critical Pitting Temperature, both depending on the contents of the material. For practical tests, a good and reliable indication is the salt mist test according IEC 60068-2-52:1996.