Rion NA-42 騒音増幅器　

Measurement functions: Sound pressure level, sound level maximum, peak sound pressure level
Preamplifier input connector
Preamplifier power supply: ±12 V or ±45 V (switchable)
Microphone bias voltage: 30/60/200 V
Frequency range: 1 Hz to 100 kHz (NA-42 only)
Battery life: Alkaline batteries (LR14) approx. 14 hours; Manganese batteries (R14P) approx. 6 hours
Ambient conditions for use: -10 °C to +50 °C (10 % to 90 % relative humidity)
Dimensions and weight: 171 (H) x 120 (W) x 236 (D) mm, 1.8 kg (without batteries)
Supplied accessories: AC adapter (NC-98C) x 1, storage case x 1, I EC R14 (size "C") batteries x 4