Instruction manual

Outline

The precision integrating sound level meter NA-27 allows digital 1/1-octave and 1/3-

octave analysis in real time. It conforms to legal requirements for quantity measurements

and to JIS and IEC standards. Using the output signal from a single microphone, the

NA-27 can determine values for different time constants and frequency weighting settings

simultaneously.

In addition to conventional noise level and sound pressure level measurements, the NA-27

can also determine the following quantities:

z Equivalent continuous sound pressure level L

z Sound exposure level L

z Maximum sound pressure level L

max

z Minimum sound pressure level L

min

z Percentile sound pressure level L

z Takt-max sound pressure level (3 or 5 s) L

tm3

, L

tm5 *

z Waveform peak sound pressure level L

peak

z Power average P_AVE

z Power sum P_SUM

z Reverberation time REVERB

* Taktmaximalpegel Mittelwert: DIN

Power averaged maximum sound pressure level in a measuring period

Measurement data can be stored in the large-capacity internal memory of the NA-27.

These data can be sent to a computer, using the built-in serial port and a high-speed block

transfer protocol. In addition, an optical port allows data collection and data transfer under

computer control, and an infrared remote control unit is also supplied.