Understanding A-C-Z noise frequency weightings
What are the different frequency weightings and why do you need to know?
Understanding the difference between A-C-Z noise frequency weightings is one of the most important things you need to know about when measuring sound. This is because picking the wrong sound level meter weighting on your sound level pressure meter could mean your results become irrelevant for the purpose and at worst invalid (not legally compliant).
You may have noticed that some sound meters allow you to choose the frequency weighting you want to measure noise at. The three most commonly used decibel weightings are ‘A’, ‘C’ and ‘Z’ as defined in the sound level meter standards IEC 61672:2013 (BS EN 61672-1:2013), but which one do you choose? We explain this is more detail below, but if you own one of our Pulsar Nova sound level meters which measures all of these frequencies simultaneously, you need not ever worry about picking the wrong weighting.
What are ‘A’, ‘C’ and ‘Z’ weightings