Sound level meter - Frequently Asked Questions

1. Overview of each measurement value

Equivalent sound level (L _eq), single-event sound exposure level (L _AE), maximum sound level (MX), minimum sound level (MN), and unleveled maximum sound level (PK) can be measured simultaneously.

• Equivalent sound level (L _eq)
  When the noise level fluctuates over time, this represents the noise level of a steady-state noise with equal energy within the measurement period.
• Single-event noise exposure level (_LAE)
  This is the noise level of a steady-state sound with a duration of 1 second that has energy equal to the A-weighted energy of each individual occurrence of a sporadic noise.
  By using measurements based on single-event noise exposure levels, it is possible to evaluate intermittently occurring noises such as pile driving noise.
• Maximum noise level (MX)
  This is the maximum level within the measurement period.
• Minimum Noise Level (MN)
  This is the minimum level within the measurement time.
• Peak level (PK)
  This value is obtained by converting the maximum value of the waveform into a level.

 

■ List of restrictions during measurement/pause

During or while measurements such as equivalent sound level or single-event noise exposure level are being taken, some panel switches will become inoperable, as shown in the table below. Please note that turning off the power during measurement will forcibly terminate the measurement.

<Memo>

• If you press [START] again while measuring equivalent sound level or single-event sound exposure level, the already measured data will be cleared (erased) and a new measurement will be started.
• Data from equivalent sound level or single-event sound exposure level measurements that display an overlevel warning are unreliable. Furthermore, overlevel (OVER) or underlevel (UNDER) warnings displayed during measurement will not disappear until measurement is restarted.
• 過大レベル警告が表示された場合には、新たにレベルレンジを設定した後、再度測定を実行してください。
• If you switch the level range or change the measurement time setting while equivalent sound level or single-event noise exposure level measurement data is being displayed, the display will switch to instantaneous values and the measurement will end. However, the equivalent sound level (L _eq) or single-event noise exposure level (_LAE) data will continue to be retained unless you press [START] again.

 

2. Measurement Procedure

For instructions on setting basic measurement conditions, please refer to the section on setting measurement conditions.

 

◆Operation

 

• Set the measurement conditions of this device for noise level measurement.
  Display screen: Standard screen (Panel switch [LIST])
  Level range: Arbitrary (Panel switch [△・▽ LEVEL])
  Frequency Correction: A (Panel switch [A / C / FLAT])
  Dynamic characteristics: FAST or SLOW (Panel switch [F/S/IMP])
• Set the measurement time.
  Press the [MEAS TIME] panel switch to set the measurement time. Here, we've set the measurement time to 5 minutes (00:05:00). To set FREE, switch the setting time to 00:00:00. When FREE is set, measurement will continue for up to 100 hours (99:59:60) until you press the [PAUSE/CONT] panel switch. However, please note that you cannot set the measurement time to more than 100 hours.
• Set the measurement data display to either equivalent noise or single-event noise exposure level measurement.
  Press the panel switch [L _P / L _eq...] to display either the equivalent noise level (L _eq) or the single-event noise exposure level (_LAE).
• Perform the measurement.
  Pressing the [START] panel switch will begin the measurement. During measurement, a measurement progress mark will be displayed, and the elapsed measurement time will be shown in the measurement time setting display.
• Read the measured value from the digital display.
  The measurement will end once the set measurement time has elapsed. The measurement progress indicator will also disappear once the measurement is complete.

 

■Temporarily suspending measurement

To pause the measurement, press the [PAUSE/CONT] panel switch. When the measurement is paused, the measurement progress indicator will change to a paused indicator. Pressing the [PAUSE/CONT] panel switch again will resume the paused measurement.

 

3. Reading the measured values

When the measurement is performed, the equivalent sound level (L _eq), single-event sound exposure level (L _AE), maximum value (MX), minimum value (MN), and peak level (PK) are measured simultaneously.

 

■Display of measured values via panel switch

Each time you press the panel switch [LP /L _eq …], the measured values will switch and be displayed in the following order:

■List display of measured values

By pressing the [LIST] panel switch to the list display screen, all measured values can be displayed. The list display can also be accessed during measurement or while measurement is paused.

<Memo>
When measuring equivalent sound level or single-event sound exposure level, the time-weighted sound level (L _X) is also measured simultaneously. Therefore, the measured time-weighted sound level can be displayed only if the sampling interval is set appropriately. For details on time-weighted sound level, please refer to the next section, "4. Measurement of Time-Weighted Sound Level".