Extech Instruments 407790A, Руководство пользователя

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407790A-EN_V2.4 1/20
4.4 Sound Band - Leq, SEL, Lmax, Lmin and LN Analysis Measurement
1. Power on the meter and wait until the SLM measurement screen appears.
2. Use the SLM 1/1 1/3 button to select the desired 1/1 OCT, 1/3 OCT or 1/1 & 1/3 OCT band or
SLM measurement screen.
3. Use the FREQ WEIGHT TIME button to select the frequency weighting characteristic. For
normal measurements, select the “A” setting.
4. Use the FREQ WEIGHT TIME button to select the time weighting characteristic. For normal
measurements, select the “F” (Fast) setting.
5. Use the  LEVEL  buttons to set the level range. Select a setting in which the main channel
all-pass value indicator is in the middle of the range.
If the “ OV ” or “ UN ” indicators appear, change the level range setting.
6. Set the measurement time from within the menu. Press the MENU key to bring up the menu
list screen.
7. Use the

+
/

-
buttons to select “A). Measurement Time” then press the

key.
8. Use the

+
/

-
and

buttons to select the desired measurement time from 1s to 23h 59m
59s.
9. Press the

key to exit the measurement time setting.
10. Press MENU key to return to the measurement screen.
11.
Press the START/STOP key to start the measurement. The previous measurement values will be cleared.
While the measurement is in progress, the

symbol flashes and the elapsed time is displayed. When
the measurement time has elapsed, the measurement is terminated automatically.
To terminate the measurement before the allocated time, press the START/STOP key.
If the indicator “OV” is shown, the processed data includes data where the sound level signal
caused an overload condition.
If the indication “UN” is shown, the processed data includes data where the sound level signal
caused an under-range condition.
During measurement, the PAUSE/CONT key can be used to pause and resume the measurement.
During pause, the pause ( ) symbol is shown. (The paused interval is not included in the
measurement time.)
Important
During measurement, the  LEVEL  button, FREQ WEIGHT TIME button, TIME WEIGHT
and SLM/RTA functions are disabled. Be sure to complete all settings before starting the
measurement.
12. When the measurement is completed, the

symbol disappears.
If “ OV ” is displayed, the processed data includes data where the sound level signal caused an
overload condition.