從附表可以看出,三綜合試驗箱與其它標準對(dui)試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)箱的(de)(de)(de)技術(shu)指(zhi)標要(yao)求(qiu)是(shi)有(you)(you)區別的(de)(de)(de),這(zhe)種(zhong)(zhong)區別主(zhu)要(yao)是(shi)對(dui)風(feng)速(su)(su)的(de)(de)(de)要(yao)求(qiu)不(bu)同,在(zai)(zai)(zai)GJB899里(li),對(dui)試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)箱溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)(du)(du)(du)誤(wu)(wu)(wu)差、相(xiang)對(dui)濕度(du)(du)(du)(du)(du)(du)誤(wu)(wu)(wu)差作(zuo)(zuo)了規(gui)定,溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)(du)(du)(du)變(bian)化速(su)(su)率(lv)在(zai)(zai)(zai)不(bu)同的(de)(de)(de)試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)剖(pou)面有(you)(you)詳(xiang)細的(de)(de)(de)規(gui)定,對(dui)風(feng)速(su)(su)卻沒(mei)有(you)(you)規(gui)定,這(zhe)是(shi)為什(shen)么呢?因為在(zai)(zai)(zai)GJB899標準里(li),試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)剖(pou)面里(li)的(de)(de)(de)溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)(du)(du)(du)變(bian)化速(su)(su)率(lv)與飛行高(gao)(gao)度(du)(du)(du)(du)(du)(du)和(he)(he)馬(ma)赫(he)數變(bian)化有(you)(you)關,它包(bao)括(kuo)了產品在(zai)(zai)(zai)使用中可能遇到(dao)的(de)(de)(de)各種(zhong)(zhong)情況,試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)剖(pou)面實際上反應了試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)件在(zai)(zai)(zai)不(bu)同的(de)(de)(de)飛行高(gao)(gao)度(du)(du)(du)(du)(du)(du)和(he)(he)馬(ma)赫(he)數時(shi)的(de)(de)(de)溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)(du)(du)(du),而這(zhe)種(zhong)(zhong)不(bu)同的(de)(de)(de)飛行高(gao)(gao)度(du)(du)(du)(du)(du)(du)和(he)(he)馬(ma)赫(he)數時(shi)的(de)(de)(de)溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)(du)(du)(du)是(shi)在(zai)(zai)(zai)不(bu)斷(duan)變(bian)化的(de)(de)(de),與其它試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)相(xiang)比,這(zhe)種(zhong)(zhong)試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)就是(shi)動(dong)態試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan),對(dui)產品的(de)(de)(de)主(zhu)要(yao)影響是(shi)各種(zhong)(zhong)溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)(du)(du)(du)和(he)(he)溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)(du)(du)(du)變(bian)化速(su)(su)率(lv),與試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)箱內風(feng)速(su)(su)的(de)(de)(de)大小(xiao)沒(mei)有(you)(you)關系,同時(shi),在(zai)(zai)(zai)制定溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)(du)(du)(du)時(shi),考慮到(dao)進(jin)人機艙(cang)空氣(qi)氣(qi)流和(he)(he)進(jin)入機艙(cang)氣(qi)流溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)(du)(du)(du);因此(ci),該標準主(zhu)要(yao)要(yao)求(qiu)的(de)(de)(de)是(shi)能夠提供一(yi)種(zhong)(zhong)溫(wen)(wen)(wen)(wen)(wen)(wen)濕度(du)(du)(du)(du)(du)(du)振動(dong)綜合(he)試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)的(de)(de)(de)環境,并能滿(man)足(zu)溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)(du)(du)(du)誤(wu)(wu)(wu)差與溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)(du)(du)(du)變(bian)化速(su)(su)率(lv)的(de)(de)(de)設備(bei)(bei),以便給(gei)出產品合(he)理的(de)(de)(de)試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)壽命,三(san)綜合(he)試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)箱正(zheng)是(shi)滿(man)足(zu)這(zhe)種(zhong)(zhong)要(yao)求(qiu)的(de)(de)(de)設備(bei)(bei),它能按照試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)剖(pou)面的(de)(de)(de)要(yao)求(qiu)進(jin)行連續的(de)(de)(de)試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)。由于試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)往往在(zai)(zai)(zai)某一(yi)溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)(du)(du)(du)下,且試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)時(shi)間很(hen)短(duan),不(bu)像一(yi)般溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)(du)(du)(du)試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)那樣還(huan)有(you)(you)一(yi)個保溫(wen)(wen)(wen)(wen)(wen)(wen)期,這(zhe)就要(yao)求(qiu)當(dang)某一(yi)溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)(du)(du)(du)變(bian)化到(dao)另-溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)(du)(du)(du)時(shi),能使試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)箱內溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)(du)(du)(du)迅速(su)(su)均勻(yun),達到(dao)試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)(du)(du)(du)誤(wu)(wu)(wu)差的(de)(de)(de)要(yao)求(qiu),假(jia)如風(feng)速(su)(su)太小(xiao),這(zhe)是(shi)很(hen)難做(zuo)到(dao)的(de)(de)(de),可以說,試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)箱的(de)(de)(de)風(feng)速(su)(su)在(zai)(zai)(zai)這(zhe)里(li)僅起到(dao)在(zai)(zai)(zai)一(yi)定溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)(du)(du)(du)范(fan)圍內迅速(su)(su)均勾試(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)箱內溫(wen)(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)(du)(du)(du)的(de)(de)(de)作(zuo)(zuo)用。
溫度/濕度/振動三綜合試驗箱(xiang)
至于其它(ta)(ta)標準對試(shi)(shi)(shi)驗(yan)(yan)箱(xiang)風速(su)的要求(qiu),在(zai)標準中已給出了說明,是(shi)(shi)為防(fang)止試(shi)(shi)(shi)驗(yan)(yan)樣品內產生不(bu)符合實際的(拎(lin)或熱)傳導,試(shi)(shi)(shi)驗(yan)(yan)目(mu)地是(shi)(shi)考驗(yan)(yan)產品在(zai)各種(zhong)溫度(du)(du)條件(jian)下貯存和(he)工作(zuo)的適(shi)應性(xing)。通常,這種(zhong)試(shi)(shi)(shi)驗(yan)(yan)在(zai)某種(zhong)溫度(du)(du)情況(kuang)下試(shi)(shi)(shi)驗(yan)(yan)時間較長,風速(su)既有(you)模擬環境的作(zuo)用又有(you)均勻試(shi)(shi)(shi)驗(yan)(yan)箱(xiang)的作(zuo)用,當達到(dao)某種(zhong)試(shi)(shi)(shi)驗(yan)(yan)溫度(du)(du)時,要求(qiu)保(bao)溫2h,使試(shi)(shi)(shi)驗(yan)(yan)箱(xiang)內溫度(du)(du)緩慢地達到(dao)均勻,可見它(ta)(ta)與(yu)可靠性(xing)試(shi)(shi)(shi)驗(yan)(yan)有(you)很大的不(bu)同。
溫濕度氣候試驗(yan)箱
從分析中我們知道,風速的不同,導致這兩類不同的設備試驗目地不同,當然,我們總希望設備能符合的.標準越多越好,實際上是有困難的,比如現有的三綜合試驗箱風速是不可調的,如改成可調,并調到符合GJB150的要求,那么在多大溫度范圍內能符合溫度誤差,恐怕就很小了,這樣就失去了意義;所以,在實際工作中,應該對試驗設備的基本的技術指標有一個比較清楚的了解,特別是三綜合試驗箱,它真正的用途就是用于產品的可靠性試驗.而不適于做其它的試驗,如果將它用于其它的試驗,會使產品得不到真正的考驗,產生不良的結果。遺憾的是三綜合試驗箱一般并沒有給出設備的風速到底有多大,很容易造成人們的錯覺,誤認為三綜合試驗箱還可以做其它的試驗。