由于實(shi)際需(xu)要(yao)，自(zi)70年(nian)代起發展了一種(zhong)稱為(wei)(wei)半消(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)室(shi)(shi)的(de)聲(sheng)(sheng)(sheng)學實(shi)驗室(shi)(shi)。此(ci)半消(xiao)(xiao)(xiao)音(yin)(yin)室(shi)(shi)除要(yao)求地(di)(di)面為(wei)(wei)硬(ying)質剛性(xing)反射(she)面外，其余(yu)與消(xiao)(xiao)(xiao)音(yin)(yin)室(shi)(shi)相同。當聲(sheng)(sheng)(sheng)源或(huo)接收(shou)器置于地(di)(di)面上時(shi)，聲(sheng)(sheng)(sheng)源和(he)接收(shou)器之間(jian)只有(you)直達聲(sheng)(sheng)(sheng)而沒有(you)反射(she)聲(sheng)(sheng)(sheng)，故在(zai)(zai)地(di)(di)面上的(de)半空間(jian)中(zhong)有(you)同消(xiao)(xiao)(xiao)音(yin)(yin)室(shi)(shi)中(zhong)那(nei)樣的(de)自(zi)由場(chang)(chang)。半消(xiao)(xiao)(xiao)音(yin)(yin)室(shi)(shi)的(de)優點是由于地(di)(di)面是硬(ying)的(de)，能承受較(jiao)大的(de)重量，適(shi)宜測量如(ru)車輛、大型機器、設備等的(de)噪聲(sheng)(sheng)(sheng)功率且使(shi)用方便，造價比消(xiao)(xiao)(xiao)音(yin)(yin)室(shi)(shi)低廉；缺點是當聲(sheng)(sheng)(sheng)源的(de)等效聲(sheng)(sheng)(sheng)中(zhong)心或(huo)接收(shou)器高出地(di)(di)面較(jiao)多(duo)時(shi)，聲(sheng)(sheng)(sheng)反射(she)的(de)影(ying)響(xiang)使(shi)聲(sheng)(sheng)(sheng)場(chang)(chang)嚴重偏離(li)自(zi)由場(chang)(chang)，這種(zhong)現象在(zai)(zai)頻率高時(shi)更為(wei)(wei)明顯，因此(ci)消(xiao)(xiao)(xiao)音(yin)(yin)聲(sheng)(sheng)(sheng)室(shi)(shi)存在(zai)(zai)有(you)高頻限。一般來(lai)說，20㎡左右的(de)消(xiao)(xiao)(xiao)音(yin)(yin)室(shi)(shi)的(de)建設費(fei)用在(zai)(zai)40萬左右，空間(jian)越(yue)大成(cheng)本(ben)也越(yue)高。南(nan)京防雨半消(xiao)(xiao)(xiao)音(yin)(yin)室(shi)(shi)施工

消(xiao)音室(shi)(shi)所(suo)用(yong)的(de)(de)(de)吸聲(sheng)(sheng)(sheng)(sheng)(sheng)材(cai)料(liao)，要求(qiu)(qiu)吸聲(sheng)(sheng)(sheng)(sheng)(sheng)系數大于0.99。一般使(shi)用(yong)漸變吸收(shou)層(ceng)，常用(yong)尖劈(pi)或圓(yuan)錐結構，以(yi)玻璃棉(mian)作吸聲(sheng)(sheng)(sheng)(sheng)(sheng)材(cai)料(liao)，也有用(yong)軟泡(pao)沫塑料(liao)的(de)(de)(de)。例如一個10×10×10m的(de)(de)(de)實驗室(shi)(shi)，每面敷設1m長的(de)(de)(de)吸聲(sheng)(sheng)(sheng)(sheng)(sheng)尖劈(pi)，其低頻(pin)截止頻(pin)率(lv)(lv)可達50Hz。在消(xiao)音室(shi)(shi)中(zhong)(zhong)進行試驗時，被測試的(de)(de)(de)對象或聲(sheng)(sheng)(sheng)(sheng)(sheng)源(yuan)等(deng)置于中(zhong)(zhong)間(jian)的(de)(de)(de)尼龍(long)絲網或鋼絲網上，由(you)于此(ci)類網能(neng)(neng)承(cheng)受(shou)的(de)(de)(de)重(zhong)量有限，故只能(neng)(neng)測試重(zhong)量輕(qing)、體積小的(de)(de)(de)聲(sheng)(sheng)(sheng)(sheng)(sheng)源(yuan)等(deng)。消(xiao)音室(shi)(shi)除了應(ying)滿足(zu)自由(you)場的(de)(de)(de)要求(qiu)(qiu)外(wai)，還要求(qiu)(qiu)有較(jiao)(jiao)低的(de)(de)(de)本底噪(zao)聲(sheng)(sheng)(sheng)(sheng)(sheng)。故在消(xiao)音室(shi)(shi)與基礎之間(jian)，還需采取一定的(de)(de)(de)隔振措施(shi)。南通檢(jian)測全消(xiao)音室(shi)(shi)建設消(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)吸聲(sheng)(sheng)(sheng)(sheng)(sheng)的(de)(de)(de)頻(pin)率(lv)(lv)特性與材(cai)料(liao)厚度(du)有關，即吸聲(sheng)(sheng)(sheng)(sheng)(sheng)較(jiao)(jiao)大值的(de)(de)(de)下限頻(pin)率(lv)(lv)大約是其厚度(du)相對應(ying)的(de)(de)(de)1/4波長的(de)(de)(de)頻(pin)率(lv)(lv)。

自由聲(sheng)(sheng)場的(de)頻率范圍(wei)和空間范圍(wei)測(ce)(ce)量(liang)過程是將(jiang)傳(chuan)聲(sheng)(sheng)器按選定(ding)的(de)路徑向吸(xi)(xi)聲(sheng)(sheng)壁(bi)面(mian)方向移動至下一個測(ce)(ce)點(dian)，測(ce)(ce)點(dian)之間的(de)距離(li)相等并不(bu)大于(yu)(yu)0.1 m，較(jiao)終的(de)測(ce)(ce)點(dian)與吸(xi)(xi)聲(sheng)(sheng)壁(bi)面(mian)的(de)距離(li)應不(bu)大于(yu)(yu)0.75 m，每條測(ce)(ce)量(liang)路徑上的(de)測(ce)(ce)點(dian)數不(bu)少于(yu)(yu)10個。依次測(ce)(ce)量(liang)各選定(ding)路徑所(suo)有測(ce)(ce)點(dian)上的(de)聲(sheng)(sheng)壓(ya)級。注(zhu)意：在設計消聲(sheng)(sheng)室(shi)時(shi)應注(zhu)意：(1)純音信號的(de)測(ce)(ce)試(shi)項目(mu)與寬帶噪(zao)聲(sheng)(sheng)信號的(de)測(ce)(ce)試(shi)項目(mu)對界面(mian)吸(xi)(xi)聲(sheng)(sheng)系(xi)數的(de)要(yao)求(qiu)有較(jiao)大差別。(2)隨之而來(lai)的(de)是關于(yu)(yu)吸(xi)(xi)聲(sheng)(sheng)結(jie)構的(de)設計。對于(yu)(yu)要(yao)求(qiu)吸(xi)(xi)聲(sheng)(sheng)系(xi)數≥0.99的(de)吸(xi)(xi)聲(sheng)(sheng)結(jie)構，一般采用尖劈形狀。

校(xiao)(xiao)準(zhun)(zhun)(zhun)：消(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)的(de)(de)校(xiao)(xiao)準(zhun)(zhun)(zhun)原先只在(zai)(zai)國家標(biao)準(zhun)(zhun)(zhun)GB6882或ISO3745《聲(sheng)(sheng)(sheng)(sheng)(sheng)學—噪(zao)聲(sheng)(sheng)(sheng)(sheng)(sheng)源聲(sheng)(sheng)(sheng)(sheng)(sheng)功率級的(de)(de)測(ce)定—消(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)和(he)半(ban)消(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)精密法》中的(de)(de)附錄A規(gui)(gui)定了測(ce)試聲(sheng)(sheng)(sheng)(sheng)(sheng)場地(di)(di)校(xiao)(xiao)準(zhun)(zhun)(zhun)程(cheng)序。2006年(nian)發(fa)布了JJF1147—2006《消(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)和(he)半(ban)消(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)聲(sheng)(sheng)(sheng)(sheng)(sheng)學特性校(xiao)(xiao)準(zhun)(zhun)(zhun)規(gui)(gui)范》詳(xiang)細地(di)(di)規(gui)(gui)定了消(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)和(he)半(ban)消(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)聲(sheng)(sheng)(sheng)(sheng)(sheng)學特性地(di)(di)確定和(he)評價。消(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)主要技(ji)術指標(biao)有兩項：①自由聲(sheng)(sheng)(sheng)(sheng)(sheng)場的(de)(de)頻率范圍和(he)空間范圍 ；②本(ben)(ben)底噪(zao)聲(sheng)(sheng)(sheng)(sheng)(sheng)。本(ben)(ben)底噪(zao)聲(sheng)(sheng)(sheng)(sheng)(sheng)地(di)(di)測(ce)量相對(dui)比較簡單，一(yi)般是在(zai)(zai)消(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)或半(ban)消(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)內選擇(ze)3 ～5個(ge)測(ce)點，依次測(ce)量各測(ce)點處的(de)(de)聲(sheng)(sheng)(sheng)(sheng)(sheng)壓級和(he)1 /1 倍頻帶聲(sheng)(sheng)(sheng)(sheng)(sheng)壓級，取相應的(de)(de)算術平均(jun)值作為該房(fang)間的(de)(de)本(ben)(ben)底噪(zao)聲(sheng)(sheng)(sheng)(sheng)(sheng)級。在(zai)(zai)寬帶噪(zao)聲(sheng)(sheng)(sheng)(sheng)(sheng)信號測(ce)試時，尤其(qi)半(ban)消(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)中噪(zao)聲(sheng)(sheng)(sheng)(sheng)(sheng)源聲(sheng)(sheng)(sheng)(sheng)(sheng)功率級的(de)(de)測(ce)定，很多情況下就不一(yi)定采用尖劈吸聲(sheng)(sheng)(sheng)(sheng)(sheng)結構的(de)(de)設計。

消(xiao)(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)，消(xiao)(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)不僅是聲(sheng)(sheng)(sheng)(sheng)(sheng)學(xue)(xue)測試(shi)(shi)的一個(ge)(ge)特殊實(shi)驗(yan)室(shi)(shi)(shi)，而且(qie)是測試(shi)(shi)系統的重要組成部分，實(shi)際上它也是聲(sheng)(sheng)(sheng)(sheng)(sheng)學(xue)(xue)測試(shi)(shi)設(she)備之一，其(qi)(qi)聲(sheng)(sheng)(sheng)(sheng)(sheng)學(xue)(xue)性能指標直接影響測試(shi)(shi)的精度。消(xiao)(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)分全消(xiao)(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)和半(ban)(ban)消(xiao)(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)。 房(fang)間(jian)的六個(ge)(ge)面(mian)全鋪設(she)吸(xi)(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)層(ceng)(ceng)的稱(cheng)為全消(xiao)(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)，一般簡稱(cheng)消(xiao)(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)。房(fang)間(jian)的六個(ge)(ge)面(mian)中只在五個(ge)(ge)面(mian)或(huo)者四個(ge)(ge)面(mian)鋪吸(xi)(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)層(ceng)(ceng)的，稱(cheng)為半(ban)(ban)消(xiao)(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)。 消(xiao)(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)的主要功能是為聲(sheng)(sheng)(sheng)(sheng)(sheng)學(xue)(xue)測試(shi)(shi)提供(gong)一個(ge)(ge)自(zi)(zi)(zi)由(you)聲(sheng)(sheng)(sheng)(sheng)(sheng)場(chang)(chang)(chang)空間(jian)或(huo)半(ban)(ban)自(zi)(zi)(zi)由(you)聲(sheng)(sheng)(sheng)(sheng)(sheng)場(chang)(chang)(chang)空間(jian)。其(qi)(qi)吸(xi)(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)處理(li)是保(bao)證消(xiao)(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)建成后取得良好的自(zi)(zi)(zi)由(you)聲(sheng)(sheng)(sheng)(sheng)(sheng)場(chang)(chang)(chang)性能的關鍵，大(da)多采用具(ju)有強(qiang)吸(xi)(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)能力的吸(xi)(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)尖(jian)劈(pi)或(huo)平板式(shi)薄板共振吸(xi)(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)結構(gou)。聲(sheng)(sheng)(sheng)(sheng)(sheng)學(xue)(xue)實(shi)驗(yan)室(shi)(shi)(shi)包括全消(xiao)(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)、半(ban)(ban)消(xiao)(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)、消(xiao)(xiao)(xiao)(xiao)聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)(shi)(shi)、消(xiao)(xiao)(xiao)(xiao)音室(shi)(shi)(shi)、無響室(shi)(shi)(shi)，靜音室(shi)(shi)(shi)，混(hun)響室(shi)(shi)(shi)、隔(ge)音室(shi)(shi)(shi)等等。南通(tong)檢測全消(xiao)(xiao)(xiao)(xiao)音室(shi)(shi)(shi)建設(she)

卦(gua)限消(xiao)聲(sheng)室是一個相鄰的(de)三個面(mian)為硬(ying)反射面(mian)，另三個面(mian)上裝(zhuang)有吸(xi)聲(sheng)尖劈的(de)實驗(yan)室。南京(jing)防(fang)雨(yu)半消(xiao)音室施(shi)工

關(guan)于(yu)消聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)大(da)小和形(xing)狀(zhuang)(zhuang)(zhuang)的(de)(de)考慮(lv)。一(yi)般消聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)的(de)(de)建筑造型幾乎(hu)不(bu)用球狀(zhuang)(zhuang)(zhuang)、柱狀(zhuang)(zhuang)(zhuang)或(huo)圓弧(hu)面的(de)(de)形(xing)狀(zhuang)(zhuang)(zhuang)。因為如果(guo)吸(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)結構(gou)的(de)(de)吸(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)系(xi)數(shu)完全大(da)于(yu)0．99，則殼體形(xing)狀(zhuang)(zhuang)(zhuang)的(de)(de)影(ying)響不(bu)大(da)；但(dan)在(zai)(zai)吸(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)系(xi)數(shu)甚(shen)低于(yu)0．99的(de)(de)情況，至少在(zai)(zai)吸(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)結構(gou)的(de)(de)截止頻率以下(xia)，吸(xi)聲(sheng)(sheng)(sheng)(sheng)(sheng)系(xi)數(shu)急遽下(xia)降，則大(da)的(de)(de)凹面會產生聚焦的(de)(de)聲(sheng)(sheng)(sheng)(sheng)(sheng)缺陷(xian)，完全不(bu)可能獲(huo)得近似的(de)(de)自由聲(sheng)(sheng)(sheng)(sheng)(sheng)場。對于(yu)機器輻射噪聲(sheng)(sheng)(sheng)(sheng)(sheng)功(gong)率的(de)(de)測試，一(yi)般測點都要在(zai)(zai)設備(bei)的(de)(de)四周空間布置(zhi)，所(suo)以多為設計成方(fang)形(xing)或(huo)長方(fang)形(xing)的(de)(de)半(ban)消聲(sheng)(sheng)(sheng)(sheng)(sheng)室(shi)．其(qi)長寬和高度(du)均可估算，即按有(you)關(guan)測試標準所(suo)要求的(de)(de)測量距離(li)、測量位置(zhi)、允許(xu)與自由聲(sheng)(sheng)(sheng)(sheng)(sheng)場的(de)(de)偏差，來確定(ding)邊(bian)長及高度(du)的(de)(de)尺(chi)寸，當然(ran)會適當留有(you)余地，還要考慮(lv)今后可能有(you)的(de)(de)設備(bei)大(da)小。南京防雨(yu)半(ban)消音室(shi)施(shi)工

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