Sound Level Measuring Amplifier [NA-42]

The NA-42 has three settings for frequency weighting (A, C, Flat) and time weighting (Fast, Slow, Impulse), which covers the requirements of general and environmental acoustic measurements. Measurement mode can be set to sound pressure level, sound level maximum, or peak sound pressure level.

One or two decimal points can be selected for the numeric readout of measurement results. In addition, the large LCD panel shows settings and various other information. Besides AC and DC output, a serial interface and a comparator output are also available. This makes it easy to integrate the unit in a measurement or monitoring system. Thanks to its handy box-shaped design, the unit is easily portable, and power can be supplied either by an AC adapter or from internal batteries. Whether in the lab or in the field, the NA-42 always is a capable performer.

 

Features

• Wide measurement frequency and level range, plus support for many different microphone types (from low to high sound pressure levels)
• High-resolution readout of sound pressure level down to two decimal points
• Integrated comparator function is convenient for use in measurement and monitoring systems
• Large, easy to read LCD panel with backlight
• Continuous operation up to 14 hours on one set of alkaline batteries (size "C" x 4). Batteries function as power failure backup during AC adapter operation.

 

Specifications

Applicable specifications	With certain microphone combinations IEC 61672-1 class1, JIS C 1509-1 class1
Measurement functions	Sound pressure level, sound level maximum, peak sound pressure level
Input section	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)
Frequency weighting characteristics	A、C、FLAT
Time weighting characteristics	F (Fast), S (Slow), I (Impulse)
Built-in filters	High-pass filter (HPF): 3rd-order Butterworth filter, 20 Hz Low-pass filter (LPF): 3rd-order Butterworth filter, 20 kHz
AC output (BNC connector)	1 Vrms full-scale Output impedance 600 Ω, load impedance 10 kΩ or more
DC output (BNC connector)	6 V (1 V/10 dB) full-scale Output impedance 50 Ω load impedance 10 kΩ or more
Power requirement	IEC R14 (size "C") batteries x 4, or AC adapter (NC-98C, supplied)
Dimensions	171 (H) x 120 (W) x 236 (D) mm
Weight	1.8 kg (without batteries)