電熱真空幹燥箱先抽真空再升溫加熱的原因 

1）如(ru)果(guo)按(an)先(xian)升(sheng)溫(wen)加(jia)熱(re)再(zai)抽(chou)真(zhen)空(kong)的(de)程(cheng)序(xu)操(cao)作(zuo)
，加(jia)熱(re)的(de)空(kong)氣(qi)被(bei)真(zhen)空(kong)泵(beng)抽(chou)出(chu)去(qu)的(de)時(shi)候(hou)
，熱(re)量(liang)必(bi)然(ran)會(hui)被(bei)帶(dai)到(dao)真(zhen)空(kong)泵(beng)上(shang)去(qu)，從(cong)而(er)導(dao)致(zhi)真(zhen)空(kong)泵(beng)溫(wen)升(sheng)過(guo)高(gao)，有(you)可(ke)能(neng)使(shi)真(zhen)空(kong)泵(beng)效(xiao)率(lv)下(xia)降(jiang)。 

2）jiarehoudeqitibeidaoxiangzhenkongyalibiao

，zhenkongyalibiaojiuhuichanshengwensheng。ruguowenshengchaoguolezhenkongyalibiaoguidingdeshiyongwendufanwei
，jiukenengshizhenkongyalibiaochanshengshizhiwucha。 

正zheng確que的de使shi用yong方fang法fa應ying該gai先xian抽chou真zhen空kong再zai升sheng溫wen加jia熱re。待dai達da到dao了le額e定ding溫wen度du後hou如ru發fa現xian真zhen空kong度du有you所suo下xia降jiang時shi再zai適shi當dang加jia抽chou一yi下xia。這zhe樣yang做zuo對dui於yu延yan長chang設she備bei的de使shi用yong壽shou命ming是shi有you利li的de。 

3）gongjianfangruzhenkongxianglichouzhenkongshiweilechouqugongjiancaizhizhongkeyichouqudeqitichengfen。ruguoxianjiaregongjian
，qitiyurejiuhuipengzhang。youyuzhenkongxiangdemifengxingfeichanghao
，pengzhangqitisuochanshengdejudayaliyoukenengshiguanchachuangganghuabolibaolie。zheshiyigeqianzaideweixian。anxianchouzhenkongzaishengwenjiaredechengxucaozuo
，jiukeyibimianzhezhongweixian。

    電熱真空幹燥箱不設溫度均勻度參數的原因 

一般的電熱（鼓風）幹燥箱均設有溫度均勻度參數：自然對流式的幹燥箱為工作溫度上限乘3%，強製對流式的幹燥箱為工作溫度上限乘2.5%。惟(wei)獨(du)電(dian)熱(re)真(zhen)空(kong)幹(gan)燥(zao)箱(xiang)不(bu)設(she)溫(wen)度(du)均(jun)勻(yun)度(du)參(can)數(shu)，這(zhe)是(shi)為(wei)什(shen)麼(me)？真(zhen)空(kong)幹(gan)燥(zao)箱(xiang)內(nei)依(yi)靠(kao)氣(qi)體(ti)分(fen)子(zi)運(yun)動(dong)使(shi)工(gong)作(zuo)室(shi)溫(wen)度(du)達(da)到(dao)均(jun)勻(yun)的(de)可(ke)能(neng)性(xing)幾(ji)乎(hu)已(yi)經(jing)沒(mei)有(you)了(le)。因(yin)此(ci)
，從(cong)概(gai)念(nian)上(shang)我(wo)們(men)就(jiu)不(bu)能(neng)再(zai)把(ba)通(tong)常(chang)電(dian)熱(re)（鼓風）幹gan燥zao箱xiang所suo規gui定ding的de溫wen度du均jun勻yun度du定ding義yi用yong到dao真zhen空kong幹gan燥zao箱xiang上shang來lai。在zai真zhen空kong狀zhuang態tai下xia設she這zhe個ge指zhi標biao也ye是shi沒mei有you意yi義yi的de。熱re輻fu射she的de量liang與yu距ju離li的de平ping方fang成cheng反fan比bi。同tong一yi個ge物wu體ti，距ju離li加jia熱re壁bi20cm處所接受的輻射熱隻是距離加熱壁10cm處的1/4。chayihenda。zhezhongxianxiangyudongtianshaitaiyangshi，shaidaotaiyangdeyimianhennuanhe，shaibudaotaiyangdeyimianbijiaolengshiyigedaoli。youyuzhenkongganzaoxiangzaijiegoushanghennanzuodaoshigongzuoshisanweikongjianneidegedianfusheredejunyunyizhi，tongshiyequefaquanweidepinggufangfa，zheyoukenengshidianrezhenkongganzaoxiangbiaozhunzhongbushewendujunyunducanshudeyuanyin。