IET 1558BP Overview
Octave bands centered at ANS Preferred Frequencies (ANS Standard S1.6-1960) and conforms to standard specification for Octave, Half-Octave, and Third-Octave-Band Filter sets S.111-1966 for Type E, Class II octave band filters Includes an A-Weighted filter For direct use with piezoelectric microphones in the 44 to 150 dB range, to 24 dB with preamplifier Internal Calibration Circuit Portable, battery-operated
