3M SE-400 user manual Positioning and tripod mount, Measurements and displayed parameters

20

Measure

Positioning and tripod mount

Positioning and tripod mount

For area monitoring and general sound level sessions, hand-held measurements are conducted by positioning the microphone directly at the noise source.

To perform stationary sound level measurements, a tripod may be used by connecting the SE-400 Series to the tripod mount while positioning it at a 0-degree incidence angle.

Figure 4-7: Measurement positioning and tripod mount

Measurements and displayed parameters

The measurements and labels which appear on the display will change based on the selected frequency weighting and response time. For example, A-weighting and Slow Response will display the following labels: LASmx, LASmn, LASeq, and LAE. The frequency weighting and response time are customizable within DMS (software). The selectable measurements are explained below. (Please see Glossary of Terms in Appendix B for more information).

Measurement/	Explanations
Parameters
SPL/LAS	Sound pressure level – is the basic measurement of noise loudness, expressed in decibels. SPL
	measured with A-weighting and slow time response is displayed as “LAS” or “SPL”.
LASMX	Maximum sound pressure level with A-weighting and slow response. (Displayed when in run or
	stop modes.)
LAPK	Peak sound pressure level with A-weighting. (Displayed when in run or stop modes.)
LASEQ	Average sound pressure level with 3,4, or 5 dB exchange rate. (Displayed when in run or stop
	modes.)
LASMIN	Minimum SPL with C-weighting and slow response. (Displayed when in run or stop modes.)
LAE	Sound Exposure Level (SEL) or Level Exposure (LE) – The sound exposure level averages the
	sampled sound over a one second period. Assuming the sampled run time to be greater than one
	second, SEL is the equivalent one-second noise that would be equal in energy to the noise that was
	sampled. SEL is typically measured using a 3dB exchange rate without a threshold. (LAE is not used
	by OSHA.)

Table 4-1: Measurement notations

Sound Examiner SE-400 Series