Sound level meter - Frequently Asked Questions

1. Important Notes

Before performing frequency analysis using 1/1 and 1/3 octave filters, please note the following:

• To perform frequency analysis using 1/1 and 1/3 octave filters, please purchase the optional 1/1 octave filter (LA-0561) or 1/3 octave filter (LA-0562) separately.
• The 1/1 and 1/3 octave filters have a gain of 10 dB. Therefore, the level range display will show a value 10 dB lower, but the measured value display takes the gain into account and can be read directly.
• 演算実行中は1/1・1/3オクターブフィルターを選択できません。
• When dual calculation mode is selected, the 1/1 and 1/3 octave filters cannot be selected. Therefore, dual-mode calculation using the 1/1 and 1/3 octave filters is not possible. Please be aware of this.
• If Wide Range is selected, you cannot select the 1/1 and 1/3 octave filters. Please set an appropriate range other than Wide before selecting the 1/1 and 1/3 octave filters.
• 騒音計のAC/DC信号出力端子からは設定した中心周波数帯域部分のみ出力されます。
• LA-2111においても1/3オクターブの10kHzと12.5kHzの設定は可能です。ただし、LA-2111は普通騒音計のため測定の周波数範囲外になります。

 

2. Procedure for measuring instantaneous values

To measure instantaneous values using 1/1 and 1/3 octave filters, follow these steps. For basic measurement condition settings, please refer to the "Setting Measurement Conditions" section.

 

◆Operation

• Set the measurement conditions for instantaneous values.

  Frequency Correction Characteristics	: Optional (Panel switch [A/C/FLAT])
  Dynamic characteristics	: Optional (Panel switch [F/S/IMP])
  Measurement mode	: Instantaneous value (Panel switch [Tact Max])
  Level range	: Except wide range (Panel switch [LEVEL ▲ ▼])

• オクターブフィルターを選択する。
  パネルスイッチ［THRU/FILTER］を押すとオクターブフィルターが選択され、画面は小画面に切り替わります。なお、1/1・1/3オクターブフィルターが装着されていないと、メッセージ［OPTION］が表示されます。
• パネルスイッチ［1/1 1/3 R.T］を押し1/1または1/3オクターブを選択する。
• Press the panel switch [FILTER FREQ] to switch the center frequency.
• 表示される瞬時値を読み取る。
  通常の瞬時値は、パネルスイッチ［THRU/FILTER］を押しオクターブフィルターの選択を解除すると表示されます。

 

3. Measurement methods for various calculations

Measure the equivalent sound level and time-weighted sound level using 1/1 and 1/3 octave filters using the following procedure.

◆Operation

• Set the measurement conditions for instantaneous values.

  Frequency Correction Characteristics	: Optional (Panel switch [A/C/FLAT])
  Dynamic characteristics	: Optional (Panel switch [F/S/IMP])
  Measurement mode	: Instantaneous value (Panel switch [Tact Max])
  Level range	: Other than wide range (Panel switch [LEVEL ▲ ▼])

• Set the measurement time.
  Press the [MEAS TIME] panel switch to set the measurement time.
  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 the panel switch [PAUSE/CONT] is pressed. However, please note that you cannot set it for more than 100 hours.
• Set the sampling interval.
  Press the [Period] panel switch for Function 2 to set the sampling interval. If the sampling interval is set to 10ms, overflow may occur if the measurement time is long.
• Therefore, please set the measurement time to within one hour. The overflow time when the measured value changes periodically is shown in the following table. Please refer to the following table to set an appropriate sampling interval and measurement time. However, if you are not measuring the time-weighted noise level, you do not need to set these parameters.

  

• オクターブフィルターを選択する。
  パネルスイッチ［THRU/FILTER］を押すとオクターブフィルターが選択され、画面は小画面に切り替わります。
• パネルスイッチ［1/1 1/3 R.T］を押し1/1または1/3オクターブを選択する。
• Press the panel switch [FILTER FREQ] to switch the center frequency.
• Perform the measurement.
  Pressing the [START] panel switch will begin the measurement. During measurement, a measurement in 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.

 

4. Reading the measured values

You can switch between displaying the values measured with 1/1 and 1/3 octave filters by following the instructions on the next page.