Sound Level Calibrator 音校準(zhǔn)器— Type 4231

　　FEATURES:

　　? Conforms to IEC942 (1988) Class 1 and ANSI

　　S1.40–1984 (R1997)

　　? Robust pocket-size design with highly stable level

　　and frequency

　　? Calibration accuracy ±0.2 dB

　　? 94 dB SPL, or 114 dB SPL for calibration in noisy

　　environments

　　? Extremely small influence of static pressure

　　? Sound pressure independent of microphone

　　equivalent volume

　　? 1 kHz calibration frequency for correct calibration

　　level independent of weighting networks

　　? Fits Brüel &Kjær 1″ and 1/2 ″ microphones (1/4″ and

　　1/8″ microphones with adaptor)

　　? Switches off automatically when removed from the

　　microphone

　　STANDARDS SATISFIED:

　　IEC 942 (1988), Sound Calibrators, Class 1

　　ANSI S1.40–1984 (R 1997), Specifications for

　　Acoustic Calibrators

　　NOMINAL SOUND PRESSURE LEVEL:

　　94.0 dB ±0.2 dB or 114.0 dB ±0.2 dB re 20 mPa

　　at reference conditions

　　FREQUENCY: 1kHz ±0.1%