9/29/09 System 824 Views 5-25Current SLM and Overall SLM ViewsCurrent SLM clears and starts overwhen the R Reset button is pressedwhile running. Overall SLM does notclear during a reset, but continuesaccumulating data.The System 824 contains two independent data buffers thatcan accumulate data separately. In essence, the instrumentbecomes two sound level meters in one. The data in theprimary buffer is referred to as the “overall” measurement,while data in the secondary buffer is referred to as the“current” measurement.The uand darrow keys can beused to cycle between the CurrentSLM, Overall SLM, Exposure, LnCentiles, and Stats views.The Current SLM and Overall SLM Views have fivecommon displays which can be cycled through usingthe rand larrow keys. Since these displays are identical theywill be discussed together. These displays are categorized asfollows:a) SPLb) Timesc) Min/MaxDailyHistoryLdn, CNEL, Leq 24, LPK-I, LPK-II, Ln’s(if desired), Lmax and Lmin arecalculated daily; and for each hour of theday the hourly Leq, EXCD Leq andbackground Leq. Can also show wind ortachometer data using externaltransducers.Metrics Measurement readings adjusted for nightand day noise impact differences.Adjustments are based on standardnighttime sound penalties criteria (i.e.LDN, CNEL, etc.) The total exceedanceand background Leq metrics are alsodisplayed.PassBy Shows the largest single 10 dB passbyevent detected with its Leq, SEL, Lmax,duration, and occurrence date and time.Wind / Tach Shows wind or tachometer data.
