【 산업위생관리자격증&산업위생을 위하여】

<TABLE height=35 cellSpacing=0 cellPadding=0 width="100%" border=0> <TBODY> <TR class=content> <TD align=left width="20%">페이지 24 / 25 </TD> <TD align=right width="80%"><A href="http://www.konetic.or.kr/calculator/cal_list.asp?page=&query=&strtitle=&strdesc=&code=5"> <IMG alt=목록 src="https://img1.daumcdn.net/relay/cafe/original/?fname=http%3A%2F%2Fwww.konetic.or.kr%2Fhome%2Fimages%2Fbtn_a_list.gif" border=0> </A><A href="http://www.konetic.or.kr/calculator/cal_list_View.asp?num=23&seqNo=849&page=&code=5&fname=1&rCnt=1&totCount=25&query=&strtitle=&strdesc="> <IMG src="https://img1.daumcdn.net/relay/cafe/original/?fname=http%3A%2F%2Fwww.konetic.or.kr%2Fhome%2Fimages%2Fbtn_a_prev.gif" border=0></A> <A href="http://www.konetic.or.kr/calculator/cal_list_View.asp?num=25&seqNo=851&page=&code=5&fname=1&rCnt=1&totCount=25&query=&strtitle=&strdesc="> <IMG src="https://img1.daumcdn.net/relay/cafe/original/?fname=http%3A%2F%2Fwww.konetic.or.kr%2Fhome%2Fimages%2Fbtn_a_next.gif" border=0></A> </TD></TR></TBODY></TABLE> <TABLE cellSpacing=0 cellPadding=0 width="100%" border=0> <TBODY> <TR> <TD bgColor=#b79348 height=3></TD></TR></TBODY></TABLE> <TABLE cellSpacing=1 cellPadding=4 width="100%" bgColor=#dddddd border=0> <TBODY> <TR bgColor=#ffffff> <TD align=middle width=100 bgColor=#f4f4f4>제목</TD> <TD align=left>감음계수(NRC, Noise reduction coefficient) </TD></TR> <TR bgColor=#ffffff> <TD align=middle width=100 bgColor=#f4f4f4>설명 </TD> <TD> <TABLE cellSpacing=0 cellPadding=0 border=0> <TBODY> <TR> <TD><BR>감음계수(NRC, Noise reduction coefficient)<BR><BR><BR>흡음재의 옥타브 밴드 250Hz, 500Hz, 1000Hz, 2000Hz의 흡음률을 이용하여 다음과 같이 계산된다.<BR><BR>NRC = 1/4 ( α250 + α500 + α1000 + α2000)<BR></TD></TR></TBODY></TABLE></TD></TR> <TR bgColor=#ffffff> <TD align=middle width=100 bgColor=#f4f4f4>예제</TD> <TD> <TABLE cellSpacing=0 cellPadding=0 width="100%" border=0> <TBODY> <TR> <TD><BR>어떤 흡음재의 옥타브 밴드별 흡음률이 다음과 같을 경우 감음계수 (NRC, Noise <BR>reduction coefficient)는 얼마인가?<BR><BR>중심주파수 …… 125Hz …… 250Hz …… 500Hz ……1000Hz …… 2000Hz ……4000Hz<BR>흡음률 ……… 0.62 ………0.70 ………0.85 ………0.83 ………0.60 ………0.30<BR><BR><풀이><BR><BR>NRC = 1/4 ( α250 + α500 + α1000 + α2000)<BR><BR>∴ NRC = 1/4 ( 0.7 + 0.85 + 0.83 + 0.6) = 0.745 ≒ 0.75 <BR></TD></TR></TBODY></TABLE></TD></TR> <TR bgColor=#ffffff> <TD colSpan=2> <TABLE cellSpacing=0 border=0> <TBODY></TBODY></TABLE></TD></TR></TBODY></TABLE> <TABLE cellSpacing=0 cellPadding=0 width="100%" border=0> <TBODY> <TR> <TD bgColor=#f4f4f4 height=3></TD></TR></TBODY></TABLE>