Calibration and adjustment of a flow meter

In short, calibration is nothing more than comparing the output of a measuring device with a reference. For Bronkhorst devices this can be done by a Bronkhorst service office, The Bronkhorst Calibration Centre or by the end user if they have the right equipment.

Re-calibration is a popular word for doing a ‘re-‘check and is often referred to as when a purchased flow meter has been sent back to the factory for a periodic calibration check. So, re-calibration is actually the same as calibration, the flow instrument will be compared to a fixed reference, again. In principle calibration does not involve any adjustment.

What is adjustment?

In practice, the most essential thing for the customer is to have a proper working measuring device. Subjecting a meter to a periodic calibration check is called a calibration “as found”. If the meter shows a deviation outside its specification limit, adjustment is advised. Adjustment can be carried out by a Bronkhorst service office, The Bronkhorst Calibration Centre or by the customer if he has the right equipment. The instrument will be adjusted to indicate the true value again. After the adjustment the instrument will be subjected to a calibration “as left”.

Why is calibration necessary?

Every instrument is subject to aging, wear and dirt. In order to ensure the instruments measure values representing the truth, a periodic calibration is often recommended.  Most applications require a periodic calibration due to legislation, norms or directives.
Minor deviations can be caused by aging of mechanical and analog electric components, this is almost unavoidable. If the deviation is more than a few percent, this is usually caused by dirt or wear. In this case full service, repair and new adjustments are recommended for the instrument.