Calibrador de nivel de sonido clase 1 con certificado de calibración frecuencia 1000 Hz
(Frequency 1000 Hz, give independence of weighting. Normal frequency: 1000 Hz. Frequency accuration: ±1 %. Normal sound pressure level: 94 dB, 114 dB. Sound level accuration: ±0.2 dB(+23 ℃ ). Power : Battery 1×6F22(9V) （battery not included).