[高低溫試驗箱]高低溫試(shi)驗箱的相關操(cao)作技(ji)巧(qiao)及操(cao)作指南

　　高(gao)低(di)溫(wen)(wen)試驗箱用于工(gong)業產品高(gao)溫(wen)(wen)、低(di)溫(wen)(wen)的(de)可靠性(xing)試驗。對電(dian)子(zi)電(dian)工(gong)、汽車摩托(tuo)、航空航天、船(chuan)舶兵器(qi)、高(gao)等院校、科研(yan)單位(wei)等相(xiang)關(guan)產品的(de)零部件及(ji)材料(liao)在高(gao)溫(wen)(wen)、低(di)溫(wen)(wen)(交變)循環(huan)變化的(de)情況(kuang)下，檢驗其各(ge)項性(xing)能指標。試驗箱由制(zhi)冷系(xi)(xi)(xi)統(tong)，加熱系(xi)(xi)(xi)統(tong)，控制(zhi)系(xi)(xi)(xi)統(tong)，濕度系(xi)(xi)(xi)統(tong)，空氣循環(huan)系(xi)(xi)(xi)統(tong)和傳(chuan)感(gan)器(qi)系(xi)(xi)(xi)統(tong)等組(zu)成(cheng)，上述系(xi)(xi)(xi)統(tong)分屬電(dian)氣和機(ji)械制(zhi)冷兩大方(fang)面。

　　電子元器件(jian)型高低溫試驗箱(xiang)

　　溫(wen)度(du)控制對于試(shi)驗箱來說至關(guan)重(zhong)要，通(tong)常(chang)通(tong)過(guo)1.全程(cheng)平(ping)均升降溫(wen)速(su)度(du)(即(ji)全程(cheng)平(ping)均以N度(du)的(de)速(su)率(lv)變化(hua))，2.線形升降溫(wen)速(su)度(du)(即(ji)以每分鐘N度(du)的(de)速(su)率(lv)變化(hua))。來實現快(kuai)速(su)溫(wen)度(du)變化(hua)試(shi)驗箱的(de)變溫(wen)速(su)率(lv)。

　　1、全程平均升降溫速度：

　　全程平均速(su)度是指(zhi)在試驗(yan)箱的變溫(wen)范圍內，最高(gao)溫(wen)度與最低(di)溫(wen)度之差值(zhi)與時間之比，目前國外各環境試驗(yan)設備生產(chan)廠家提供的變溫(wen)速(su)率的技(ji)術參數都是指(zhi)的全程平均速(su)率。

　　2、線形升降溫(wen)速度：

　　線(xian)(xian)形升降(jiang)(jiang)溫(wen)(wen)(wen)速(su)(su)(su)(su)度(du)(du)指在(zai)(zai)任(ren)意的(de)(de)每(mei)5min時間段(duan)內，能夠保證的(de)(de)變溫(wen)(wen)(wen)速(su)(su)(su)(su)率(lv)。而實際(ji)上對(dui)于快(kuai)速(su)(su)(su)(su)溫(wen)(wen)(wen)度(du)(du)變化高低溫(wen)(wen)(wen)試驗箱(xiang)來說，保證線(xian)(xian)形升降(jiang)(jiang)溫(wen)(wen)(wen)速(su)(su)(su)(su)度(du)(du)的(de)(de)難度(du)(du)最(zui)大、最(zui)關鍵的(de)(de)一段(duan)是(shi)，渦街流(liu)量計(ji)在(zai)(zai)降(jiang)(jiang)溫(wen)(wen)(wen)段(duan)最(zui)后的(de)(de)一個(ge)5min的(de)(de)時間段(duan)內，試驗箱(xiang)可以達到的(de)(de)降(jiang)(jiang)溫(wen)(wen)(wen)速(su)(su)(su)(su)率(lv)。因(yin)此試驗設備最(zui)好具有全程平(ping)均(jun)(jun)升降(jiang)(jiang)溫(wen)(wen)(wen)速(su)(su)(su)(su)度(du)(du)和線(xian)(xian)形升降(jiang)(jiang)溫(wen)(wen)(wen)速(su)(su)(su)(su)度(du)(du)(每(mei)5min平(ping)均(jun)(jun)速(su)(su)(su)(su)度(du)(du))這(zhe)兩個(ge)參(can)數(shu)，一般來說，線(xian)(xian)形升降(jiang)(jiang)溫(wen)(wen)(wen)速(su)(su)(su)(su)度(du)(du)(每(mei)5min平(ping)均(jun)(jun)速(su)(su)(su)(su)度(du)(du))是(shi)全程平(ping)均(jun)(jun)升降(jiang)(jiang)溫(wen)(wen)(wen)速(su)(su)(su)(su)度(du)(du)的(de)(de)1/2。

　　由于(yu)高低溫(wen)(wen)(wen)(wen)試(shi)驗箱(xiang)(xiang)(xiang)有(you)(you)恒(heng)(heng)(heng)定(ding)(ding)試(shi)驗箱(xiang)(xiang)(xiang)與交(jiao)變(bian)試(shi)驗箱(xiang)(xiang)(xiang)之分，所以(yi)(yi)控(kong)制(zhi)(zhi)(zhi)(zhi)方式(shi)(shi)也就有(you)(you)了不同，對(dui)于(yu)恒(heng)(heng)(heng)定(ding)(ding)試(shi)驗箱(xiang)(xiang)(xiang)來說，其其控(kong)制(zhi)(zhi)(zhi)(zhi)方式(shi)(shi)為：設(she)定(ding)(ding)一(yi)個(ge)目標溫(wen)(wen)(wen)(wen)度(du)(du)，試(shi)驗箱(xiang)(xiang)(xiang)具有(you)(you)自動恒(heng)(heng)(heng)溫(wen)(wen)(wen)(wen)到(dao)目標溫(wen)(wen)(wen)(wen)度(du)(du)點(dian)的(de)(de)能力。恒(heng)(heng)(heng)定(ding)(ding)溫(wen)(wen)(wen)(wen)濕(shi)度(du)(du)試(shi)驗箱(xiang)(xiang)(xiang)的(de)(de)控(kong)制(zhi)(zhi)(zhi)(zhi)控(kong)制(zhi)(zhi)(zhi)(zhi)方式(shi)(shi)也類似，設(she)定(ding)(ding)一(yi)個(ge)目標溫(wen)(wen)(wen)(wen)度(du)(du)、濕(shi)度(du)(du)點(dian)，試(shi)驗箱(xiang)(xiang)(xiang)具有(you)(you)自動恒(heng)(heng)(heng)溫(wen)(wen)(wen)(wen)到(dao)目標溫(wen)(wen)(wen)(wen)度(du)(du)、濕(shi)度(du)(du)點(dian)的(de)(de)能力。高、低溫(wen)(wen)(wen)(wen)交(jiao)變(bian)試(shi)驗箱(xiang)(xiang)(xiang)具有(you)(you)設(she)定(ding)(ding)一(yi)條(tiao)或(huo)者多條(tiao)高低溫(wen)(wen)(wen)(wen)變(bian)化(hua)、循環的(de)(de)程(cheng)序，試(shi)驗箱(xiang)(xiang)(xiang)有(you)(you)能力根據預置的(de)(de)曲(qu)(qu)線完(wan)成試(shi)驗過(guo)程(cheng)，并(bing)且可以(yi)(yi)在最大(da)升溫(wen)(wen)(wen)(wen)、降(jiang)溫(wen)(wen)(wen)(wen)速率能力的(de)(de)范(fan)圍內，精確控(kong)制(zhi)(zhi)(zhi)(zhi)升溫(wen)(wen)(wen)(wen)、降(jiang)溫(wen)(wen)(wen)(wen)的(de)(de)速率，即(ji)可以(yi)(yi)根據設(she)定(ding)(ding)的(de)(de)曲(qu)(qu)線的(de)(de)斜率控(kong)制(zhi)(zhi)(zhi)(zhi)升溫(wen)(wen)(wen)(wen)、降(jiang)溫(wen)(wen)(wen)(wen)速率。

　　交(jiao)變(bian)(bian)濕熱試(shi)(shi)(shi)驗(yan)(yan)(yan)箱也具有(you)預置溫度、濕度曲線，并(bing)且根(gen)據預置進行控制(zhi)的能(neng)力(li)。當然，交(jiao)變(bian)(bian)試(shi)(shi)(shi)驗(yan)(yan)(yan)箱都具有(you)恒(heng)定(ding)試(shi)(shi)(shi)驗(yan)(yan)(yan)箱的功(gong)能(neng)，但交(jiao)變(bian)(bian)試(shi)(shi)(shi)驗(yan)(yan)(yan)箱的制(zhi)造成本較高，因為(wei)交(jiao)變(bian)(bian)試(shi)(shi)(shi)驗(yan)(yan)(yan)箱需(xu)(xu)配(pei)置有(you)曲線自動(dong)記錄裝(zhuang)置、程序控制(zhi)儀，還須解(jie)決(jue)試(shi)(shi)(shi)驗(yan)(yan)(yan)箱在工作(zuo)室內(nei)溫度較高的情況下開啟制(zhi)冷機(ji)等(deng)問題(ti)，因此，交(jiao)變(bian)(bian)試(shi)(shi)(shi)驗(yan)(yan)(yan)箱的價(jia)格比恒(heng)定(ding)試(shi)(shi)(shi)驗(yan)(yan)(yan)箱的價(jia)格一般要高20%以(yi)上。因此，我們應(ying)當實事(shi)求(qiu)是(shi)的以(yi)試(shi)(shi)(shi)驗(yan)(yan)(yan)方法的需(xu)(xu)要為(wei)出發點，選用恒(heng)定(ding)試(shi)(shi)(shi)驗(yan)(yan)(yan)箱或(huo)者是(shi)交(jiao)變(bian)(bian)試(shi)(shi)(shi)驗(yan)(yan)(yan)箱。

　　為什么要使用高低溫(wen)濕熱(re)試(shi)驗箱來檢(jian)測產品?

　　1)濕熱(re)對產品的影響：

　　潮濕(shi)環境可以(yi)引起(qi)(qi)材(cai)料的(de)機械(xie)性(xing)能(neng)和化(hua)(hua)學(xue)(xue)性(xing)能(neng)的(de)變(bian)化(hua)(hua)，如體膨脹(zhang)、機械(xie)強度(du)降(jiang)低等(deng)。 由(you)于(yu)(yu)(yu)(yu)吸(xi)(xi)潮，使密封(feng)產(chan)(chan)(chan)品(pin)的(de)密封(feng)性(xing)能(neng)降(jiang)低或(huo)遭破壞、產(chan)(chan)(chan)品(pin)表面(mian)(mian)涂(tu)敷層(ceng)剝(bo)落、產(chan)(chan)(chan)品(pin)標記模糊(hu)不清(qing)等(deng)。 由(you)于(yu)(yu)(yu)(yu)凝(ning)露(lu)和吸(xi)(xi)附作用，使絕(jue)緣材(cai)料的(de)表面(mian)(mian)絕(jue)緣電(dian)阻下降(jiang)。 由(you)于(yu)(yu)(yu)(yu)水(shui)分的(de)吸(xi)(xi)收和擴散作用，使絕(jue)緣材(cai)料的(de)體積電(dian)阻下降(jiang)，從而(er)(er)產(chan)(chan)(chan)生漏電(dian)流。 對于(yu)(yu)(yu)(yu)整機設(she)備，將(jiang)會導致靈敏度(du)降(jiang)低、頻率漂移等(deng)。 濕(shi)熱的(de)腐(fu)(fu)蝕作用是(shi)由(you)于(yu)(yu)(yu)(yu)空氣中含有(you)少量的(de)酸、堿性(xing)雜質(zhi)，或(huo)由(you)于(yu)(yu)(yu)(yu)產(chan)(chan)(chan)品(pin)表面(mian)(mian)附著(zhu)如焊渣(zha)、汗(han)漬等(deng)污染物質(zhi)而(er)(er)引起(qi)(qi)間接的(de)化(hua)(hua)學(xue)(xue)和電(dian)化(hua)(hua)學(xue)(xue)腐(fu)(fu)蝕作用。 對于(yu)(yu)(yu)(yu)不同(tong)的(de)金(jin)屬(shu)材(cai)料、金(jin)屬(shu)和非金(jin)屬(shu)材(cai)料之間，即使在(zai)沒有(you)污染物質(zhi)存在(zai)的(de)條件(jian)下，只要有(you)適宜的(de)濕(shi)度(du)條件(jian)或(huo)有(you)凝(ning)露(lu)，由(you)于(yu)(yu)(yu)(yu)化(hua)(hua)學(xue)(xue)或(huo)電(dian)化(hua)(hua)學(xue)(xue)作用的(de)結(jie)果，也會引起(qi)(qi)不同(tong)程度(du)的(de)腐(fu)(fu)蝕。

　　2)濕度環境效應

　　1. 材料的膨脹。

　　2. 物理(li)強度的喪失。

　　3. 化(hua)學性能(neng)的改變。

　　4. 絕(jue)緣材料性(xing)能(neng)的退化。

　　5. 電性(xing)短路。

　　6. 活動機件由(you)于腐(fu)蝕及(ji)潤滑劑污濁造(zao)成卡死。

　　7. 金(jin)屬材料的氧化腐蝕(shi)。

　　8. 可(ke)塑性的喪失。

　　9. 加速化學反應。

　　10.電子元件的(de)退化(hua)。

　　國內(nei)外環境試(shi)驗(yan)箱給(gei)出的濕(shi)(shi)(shi)度(du)(du)指標(biao)大都(dou)是20～98%RH或30～98%RH，如果濕(shi)(shi)(shi)熱試(shi)驗(yan)箱沒有除濕(shi)(shi)(shi)系統(tong)，則濕(shi)(shi)(shi)度(du)(du)范圍為60～98%，這一類試(shi)驗(yan)箱只能做高濕(shi)(shi)(shi)試(shi)驗(yan)，但它的價(jia)格低得(de)多。值得(de)注意的是在濕(shi)(shi)(shi)度(du)(du)指標(biao)后面應(ying)該注明相(xiang)應(ying)的溫(wen)(wen)(wen)度(du)(du)范圍，或給(gei)出最低露點溫(wen)(wen)(wen)度(du)(du)。因為相(xiang)對(dui)濕(shi)(shi)(shi)度(du)(du)是與溫(wen)(wen)(wen)度(du)(du)直接相(xiang)關的，對(dui)于同樣的絕對(dui)含(han)(han)濕(shi)(shi)(shi)量，溫(wen)(wen)(wen)度(du)(du)越(yue)高，相(xiang)對(dui)濕(shi)(shi)(shi)度(du)(du)就越(yue)小，如絕對(dui)含(han)(han)濕(shi)(shi)(shi)量為5g/Kg(指1公斤(jin)干空氣中含(han)(han)有5克的水蒸汽)，當溫(wen)(wen)(wen)度(du)(du)為29℃時，相(xiang)對(dui)濕(shi)(shi)(shi)度(du)(du)為20%RH，溫(wen)(wen)(wen)度(du)(du)為6℃時，相(xiang)對(dui)濕(shi)(shi)(shi)度(du)(du)為90%RH，當溫(wen)(wen)(wen)度(du)(du)降至4℃以下，相(xiang)對(dui)濕(shi)(shi)(shi)度(du)(du)超過100%，在箱體內(nei)會出現結露現象。

　　濕(shi)(shi)(shi)熱試(shi)驗(yan)箱(xiang)(xiang)除濕(shi)(shi)(shi)系(xi)統(tong)采用蒸發器(qi)(qi)盤管露(lu)點溫(wen)度(du)(du)(du)(du)層(ceng)流接觸式(shi)加濕(shi)(shi)(shi)器(qi)(qi)，對于(yu)濕(shi)(shi)(shi)度(du)(du)(du)(du)的(de)(de)精(jing)(jing)度(du)(du)(du)(du)控(kong)(kong)制(zhi)(zhi)，環境試(shi)驗(yan)箱(xiang)(xiang)中測量濕(shi)(shi)(shi)度(du)(du)(du)(du)多數是采用干濕(shi)(shi)(shi)球法，環境試(shi)驗(yan)設備的(de)(de)制(zhi)(zhi)造標準(zhun)GB10586要(yao)求(qiu)(qiu)，相(xiang)對濕(shi)(shi)(shi)度(du)(du)(du)(du)偏差應在+2-3%RH。為滿足濕(shi)(shi)(shi)度(du)(du)(du)(du)控(kong)(kong)制(zhi)(zhi)精(jing)(jing)度(du)(du)(du)(du)的(de)(de)要(yao)求(qiu)(qiu)，濕(shi)(shi)(shi)度(du)(du)(du)(du)試(shi)驗(yan)箱(xiang)(xiang)的(de)(de)溫(wen)度(du)(du)(du)(du)控(kong)(kong)制(zhi)(zhi)精(jing)(jing)度(du)(du)(du)(du)較高，溫(wen)度(du)(du)(du)(du)波動一般小于(yu)±0.2℃。否則很難達到濕(shi)(shi)(shi)度(du)(du)(du)(du)控(kong)(kong)制(zhi)(zhi)精(jing)(jing)度(du)(du)(du)(du)的(de)(de)要(yao)求(qiu)(qiu)。

　　廣東劍喬(qiao)試(shi)(shi)驗(yan)(yan)設備有限公司是專注于振(zhen)動及環境試(shi)(shi)驗(yan)(yan)設備研(yan)發、生產、銷售大型生產廠(chang)家(jia),主營(ying)產品(pin)：振(zhen)動臺、振(zhen)動試(shi)(shi)驗(yan)(yan)機、振(zhen)動試(shi)(shi)驗(yan)(yan)臺、沖擊(ji)試(shi)(shi)驗(yan)(yan)臺、沖擊(ji)試(shi)(shi)驗(yan)(yan)機、老化房、恒(heng)(heng)(heng)溫(wen)(wen)恒(heng)(heng)(heng)濕試(shi)(shi)驗(yan)(yan)室(shi)、恒(heng)(heng)(heng)溫(wen)(wen)恒(heng)(heng)(heng)濕機、快速溫(wen)(wen)變試(shi)(shi)驗(yan)(yan)箱(xiang)(xiang)、高(gao)低溫(wen)(wen)試(shi)(shi)驗(yan)(yan)箱(xiang)(xiang)、冷熱沖擊(ji)試(shi)(shi)驗(yan)(yan)箱(xiang)(xiang)、冷熱沖擊(ji)箱(xiang)(xiang)、恒(heng)(heng)(heng)溫(wen)(wen)恒(heng)(heng)(heng)濕箱(xiang)(xiang)、恒(heng)(heng)(heng)溫(wen)(wen)恒(heng)(heng)(heng)濕試(shi)(shi)驗(yan)(yan)箱(xiang)(xiang)等產品(pin)。