3M eg3, eg4 user manual Views on Explanation Edge, Dose, Response Level, Fast, Slow, Weighting

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Views on the Edge

Definitions of data log values and views

 

Views on the

 

 

Explanation

 

 

Edge

 

 

 

 

 

LTWA

 

 

Time-weighted average - is the sound level (in dB) that is accumulated for any time period but

 

 

 

 

 

with its average level computed over an 8-hour period. TWA is usually measured with A-weighting,

 

 

 

 

 

 

 

 

 

 

Slow response, and a 5 dB exchange rate.

 

 

 

 

 

All sound levels at or above the threshold level (cutoff level) are averaged into the

 

 

 

 

 

calculations relating to noise exposure. TWA is calculated with no cutoff, with cutoff 1 (typically 80

 

 

 

 

 

dB), or with cutoff 2 (typically 90 dB).

 

 

 

 

 

If the time period is less than 8 hours, the TWA will be less than the Lavg/Leq.

 

 

 

 

 

If the time period is more than 8 hours, the TWA will be more than the

 

 

 

 

 

Lavg/Leq.

 

 

LAE

 

 

Sound Exposure Level (SEL) 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 3 dB exchange rate without a threshold. (LAE is not used by

 

 

 

 

 

OSHA.)

 

 

Dose

 

 

Dose - Related to the Criterion Level, a dose reading of 100% is the maximum

 

 

 

 

 

allowable exposure to accumulated noise. For OSHA, 100% dose occurs for

 

 

 

 

 

an average sound level of 90 dB over an 8 hour period (or any equivalent

 

 

 

 

 

exposure). (Please see Glossary of Terms for more details, page 59).

 

 

UL

 

 

Upper Limit - is the amount of time that the sound level exceeds a preset

 

 

 

 

 

level (the Upper Limit).

 

 

Response Level

 

 

Typically, noise is not constant. Using a response of Slow or Fast simply

 

 

(Fast, Slow)

 

 

flattens the noise fluctuation and makes the sound level easier to work with.

 

 

 

 

 

Slow: 1 second (1,000 milliseconds, or msec)

 

 

 

 

 

Fast: 0.125 second (125 milliseconds)

 

 

RT

 

 

Run Time - The overall time of your noise study.

 

 

Weighting

 

 

A and C weighting are types of frequency filters that cover the frequency range of human hearing

 

 

 

 

 

(20Hz to 20 kHz).

 

 

(A, C)

 

 

 

 

 

 

“A” weighting: The “A” weighted filter attempts to make the dosimeter respond closer to

 

 

 

 

 

 

 

 

 

 

the way the human ear hears. It attenuates the frequencies below several hundred hertz as

 

 

 

 

 

well as the high frequencies above six thousand hertz. “A” weighted measurements are

 

 

 

 

 

often reported as dBA.

 

 

 

 

 

“C” weighting: provides a fairly flat frequency response with only slight attenuation of the

 

 

 

 

 

very high and very low frequencies. “C” weighting is intended to represent how the ear

 

 

 

 

 

perceives sound at high decibel levels and is often used as a “flat” response when LINEAR

 

 

 

 

 

is not available. “C” weighted measurements are often reported as dBC.

 

 

Table 3-1: Dosimeter parameters and definitions (continued

 

053-644, Rev E

Page 20

eg4 & eg3

Image 26
Contents Edge Turning off Display and keypad Introduction DosimetryGetting started Checking the equipment Turning on 3MTMDetection Mangement Software DMSDocking Noise studiesViews on the Edge Running studiesTechnical Support Appendix a Specifications StandardsStopping a study User InterfaceINDEX………………………………………………………………………………… Physical attributes of EdgeDock1 and EdgeDock5Contacting 3M Quest Technologies International customers List of Tables Introduction Illustration of how the dosimeter operates and processes Range of sound Time history manufacturing Peak Measurement 121.20 dB View your results via QSP-II Setting-up your dosimeter parameters for your noise studiesRunning your studies Develop corrective actionsParameter setup screen for eg4 Getting started Powered on with measurement view displayed LED indicators explained Edge LED Explanation IndicatorEdge Keypad EdgeDock1 EdgeDock1 and EdgeDock5 components  Powering EdgeDock1 or EdgeDock5 Attaching charger adapter to EdgeDock1 and EdgeDock5 How to charge Docking the Edge with a single and 5-bay docksBackside of EdgeDock1 Setting-up the Edge via DMS Sample summary data from DMS reporting Logging Views on Explanation Dosimeter views and definitionsDose WeightingViews on Explanation Edge Response LevelDescriptors Variants Lmax variants Dosimeter measurement descriptors/variantsCommunicating connecting a docked Edge to a pc New Hardware wizard for Edge Dock Dosimeter screen Dosimeter fields explained for the Edge Edge display screen Edge security setting Edge auto run screen 10 Edge firmware update screen 11 Saving and sending Edge setups Quick Help List typical dosimetry session Quick help list for running a study How to attach the dosimeter Positioning/Attaching the Edge Checking battery power Battery indicators Calibrating the dosimeter Calibrating Reset On/off enterContrast icon Checkmark icon Is the selection to  ContrastOn/off/enter button  How to run a noise study Display screen while runningIndicators i.e., run, stop, battery, and OL  How to stop a noise studyIndicator Icon Explanation  Viewing measurements Measurement view on the Edge How to lock or secure  How to unlock Downloading Communicating between your pc and the EdgeDMS start screen Recent downloaded data  Selecting and viewing dataExample of Edge Report in DMS Panel layout view viewing the data in charts and graphs Technical Support Microphone and windscreen assembly  Attaching/Detaching the windscreen and microphoneHard Hat Attachment Kit Size HousingWeight Memory capacity LifeType OperatingLED Green indicator LED amber indicatorLED Red indicator Size of EdgeDock1Dosimeters Status indicatorsDisplayed Data RMS RangeLogging eg4 only SecurityAuto-Run Analog Board Edge Block Diagram Service Department and Technical Support 1 800 International customersBackground Noise, effects Criterion Level CL Combining Noise sourcesCrest Factor Dose Criterion TimeDecibel dB Exchange Rate ER also known as the Doubling RateLavg Average Level Free field setting microphoneHearing Conservation HC Hertz Hz Lep,dMaximum Level Lmax Leq Equivalent LevelLogging Measurement RangeRandom incidence microphone PEL Permissible Exposure LevelProjected Time Response TimeTWA Time Weighted Average ThresholdWindscreen Weighting A, C, Z, etcUpper Limit UL Dose = Index Edge DockQSP-II Running studies
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