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Preparing to measure

Measurement range

Measurement range

You select the decibel range before running the first study in the session. Setting the measurement range helps keep the desired measurements within the linear range of operation. If you don’t make an optimal range selection, low levels of sound can be hidden in the instrument noise (below the noise floor of the instrument), and high levels of sound can be distorted (the instrument is “overloaded”). Measurements at these extremes are invalid. For information about these and other terms that may be unfamiliar to you, see the glossary in this manual (Appendix B, “Glossary”).

Measurement range selection

1.From Start screen, select either View Current Study or View Session.

The bar chart screen appears. To select, press

arrows and then

press

.

 

-NOTE: The bar chart screen may appear with a different measurement

displayed and a different range. This is dependent on the settings you may have selected. (For more information, please see “Measurement Type”, on page 26)

2.(Depending on if you selected basic SLM or applied 1/1 or 1/3 octave

band filters) a bar chart screen or a filtered bar chart screen will appear,

press . This changes the range, and the change is confirmed in the screen in two ways.

Ranges - A different range may appear each time you press an arrow key. The instrument provides eight selectable ranges, each with different minimum and maximum values. (For more information about ranges, please see “Ranges” in the Specifications in Appendix A, on page 123).

SPL value Depending on if you have the instrument set to measure basic sound level measurements (see “A” below) or filtered sound level measurements (see “B” below), the following two types of screens may appear. The level increases or decreases in relation to the range selection

Range

Range

Figure 5-1: Bar chart screen (A) and Filtered Bar Chart (B)

Models SE and DL

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3M DL, SE user manual Measurement range