Zeroing of pressure instruments

Adjusting the zero point is important when high accuracy is required.

The zero point signal of a pressure transmitter can shift:

  • when it is installed, because of the mounting position or mechanical strain on the pressure connection,
  • in operation, because of temperature changes,
  • over a long time, because of aging.

Long-term stability (the maximum signal drift per year) is a quality parameter which must be specified in the data sheets.


When, how often?

If high accuracy is required,

  • adjusting the zero offset signal during commissioning, after the instrument has been installed
  • and subsequently according to requirements (e.g. every 12 months).

For certain installations, such as in power plants, regulations demand a documented check of the zero offset signal.