1. Meet the standard of IEC 60942 2. Two types: Multi- ... -sound pressure level (S type) FEATURES 1. Meetthe standard of IEC 60942 2. Two types: Multi-frequency ( ... , 84dB, 94dB, 104dB94dB74dB, 84dB, 94dB, 104dB94dBStandard deviation for SPL Smaller than ±0.3 dBSmaller than ± ... 500Hz, 250Hz, 125Hz1000Hz1 000Hz, 500Hz, 250Hz, 125HzStandard deviation for FrequencySmaller than ±1 %Distortion(THD)≤1 %Power ...