Three frequency weighting networks called A, C and Z are available simultaneously.
A: The A network simulates human hearing ability at low to medium sound levels. This is the most used weighting network.
C: The C network is mainly used for Peak level detections and it simulates the hearing ability at higher levels.
Z: The Z weighting is in fact no weighting and covers the frequency range from 20 Hz to 20 kHz.
Measurement standards often tell which weighting networks to use for special purposes.