407790 Datasheet, PDF (12/18 Pages) Extech Instruments Corporation. – Real Time Octave Band Analyzer

FAST LA
dB
100
W
75.2 dB
90
80
70
60
50
40
30
Hz 31.5 125 500 2k
8k L W
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3. Use the LM/ 1/1/ 1/3 button to select the desired SLM, 1/1 or 1/3 octave band sound
pressure level measurement screen.
4. Use the FREQ WGHT button to select the desired LA, LC or LP frequency weighting
setting.
5. Use the TIME CONST button to select the desired FAST or SLOW time constant setting.
Normally, the “FAST” setting should be used.
6. Use the LEVEL button to select the level range. Choose a setting in which the
“OVER” and “UNDER” indications do not appear. In SLM mode, the dynamic range is
30~130dB, so the LEVEL key is not activated.
7. Press the START/STOP button. The “” mark appears on the display and the
equivalent continuous sound pressure level measurement begins.
8. The following status displays are used in the mode “measuring”, “ ▌▌pause ” or “■
terminate”. Use the MODE button to select any parameter L, Leq, LE, Lmax or Lmin.
9. When the measurement time set in step 2 has elapsed, the measurement terminates
automatically.
10. Terminate the measurement earlier by pressing the PAUSE/CONT button, “▌▌ ” will
appear on the display. Press PAUSE/CONT to resume measuring.
11. Press the START/STOP button to stop measuring, the “■ ” mark will appear on the
display.
12. Press the MODE button to display the LAeq , LAE or other parameter value.
Note: In this measurement mode, the frequency weighting, time weighting and SLM/ 1/1/
1/3 mode cannot be changed.
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Model 407790 Ver. 2.1 9/07