Accurate acoustical measurements, or more precisely measurements of well-defined (and low) uncertainty, require three essential elements:

• A traceably-calibrated measuring instrument, that is, one whose calibration is linked by an unbroken chain of comparisons to a primary standard of measurement
• An agreed method of measurement, preferably standardised nationally or internationally by an appropriate standardisation body (BSI, CEN, ISO, IEC)
• A trained and informed measurement practitioner

In acoustical measurements, perhaps more than in some other fields, these three elements are equally important. Well trained practitioners using well calibrated instruments would not necessarily agree on the results of their measurements if they could not rely on the body of procedural Standards which define measurement protocols and reference values which allow results to be compared. These Standards form the important link between the objective measurements and attempts to quantify annoyance or risk. But, for brevity, the remainder of this paper will concentrate solely on the first element.

Measuring Instrumentation >>