Three frequency weighting networks called A, C and Z are available simultaneously.
The weighting networks are defined in the IEC61672 standard.
Specifications for weighting networks
A-Network
The A network simulates human hearing ability at low to medium sound levels. This is the most used weighting network.
C-Network
The C network is mainly used for Peak level detections and it simulates the hearing ability at higher levels.
Z-Network
The Z weighting is in fact no weighting and covers the frequency range from 20 Hz to 20 kHz.
The figure below shows the weighting curves for the different networks.
