Rion NL-42A, Instruction Manual, Page: 147 / 154

Calibration
Internal calibration
Electrical calibration with signal from built-in oscillator
(1 kHz, [scale upper limit of the bar graph] − 6 dB)
Acoustic calibration
NC-75/NC-74 (1 kHz, 93.9 dB [NL-42A] / 94.0 dB
[NL-52A])
NC-72B/NC-72A (250 Hz, 114.0 dB)
Correction functions
Windscreen correction
Reduces infl uence of mounted windscreen on frequency
response characteristics.
Turning on/off the correction function is done from
the menu screen.
* The unit complies with IEC 61672-1, JIS C 1509-1, JIS
C 1516 and ANSI/ASA S1.4 with windscreen mounted.
Diffuse sound fi eld correction
Corrects frequency response to meet the standard
(ANSI/ASA S1.4) in diffuse sound fi eld.
Turning on/off the correction function is done from
the menu screen.
Delay time Sets a delay in starting measurement from the point of
pressing the START/STOP key.
Setting range: The delay time is selected from OFF,
1, 3, 5 or 10 sec and set to it.
Previous data removal function (Back-erase function)
When measurement is paused with the PAUSE/CONT
key, the data of some seconds from the point of pressing
the PAUSE/CONT key are excluded from processing.
During Auto store or when waveform recording function
is set to ON, this function has no effect.
Setting range: The time is selected from OFF, 1, 3
or 5 sec and set to it.
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Specifi cations