本(ben)實用(yong)新(xin)型涉(she)及一種最大(da)氣泡法測定(ding)液體表面張力(li)試(shi)驗的裝置(zhi)。

背景技術：

在(zai)(zai)最大(da)(da)(da)氣(qi)(qi)(qi)(qi)(qi)泡(pao)法測(ce)定(ding)液(ye)(ye)體(ti)表(biao)面(mian)(mian)(mian)(mian)張力(li)(li)(li)(li)試驗中，通過滴(di)(di)液(ye)(ye)漏斗緩慢滴(di)(di)液(ye)(ye)，在(zai)(zai)表(biao)面(mian)(mian)(mian)(mian)張力(li)(li)(li)(li)測(ce)定(ding)裝(zhuang)(zhuang)置的(de)(de)(de)密(mi)封體(ti)系(xi)中形成負壓(ya)。由于毛(mao)(mao)細(xi)管(guan)(guan)上端(duan)(duan)口與(yu)(yu)(yu)大(da)(da)(da)氣(qi)(qi)(qi)(qi)(qi)相(xiang)通，因(yin)此隨(sui)著(zhu)體(ti)系(xi)中壓(ya)力(li)(li)(li)(li)逐(zhu)(zhu)漸(jian)(jian)(jian)降低，大(da)(da)(da)氣(qi)(qi)(qi)(qi)(qi)環境與(yu)(yu)(yu)表(biao)面(mian)(mian)(mian)(mian)張力(li)(li)(li)(li)測(ce)定(ding)裝(zhuang)(zhuang)置密(mi)封體(ti)系(xi)之間的(de)(de)(de)壓(ya)差(cha)(cha)驅動空氣(qi)(qi)(qi)(qi)(qi)試圖從毛(mao)(mao)細(xi)管(guan)(guan)下端(duan)(duan)端(duan)(duan)面(mian)(mian)(mian)(mian)和表(biao)面(mian)(mian)(mian)(mian)張力(li)(li)(li)(li)實驗裝(zhuang)(zhuang)樣(yang)試管(guan)(guan)內(nei)試樣(yang)液(ye)(ye)面(mian)(mian)(mian)(mian)之間的(de)(de)(de)接(jie)觸界面(mian)(mian)(mian)(mian)處逸(yi)出。而在(zai)(zai)接(jie)觸界面(mian)(mian)(mian)(mian)處一旦有氣(qi)(qi)(qi)(qi)(qi)泡(pao)形成，氣(qi)(qi)(qi)(qi)(qi)泡(pao)即要承受彎(wan)曲(qu)液(ye)(ye)面(mian)(mian)(mian)(mian)附加(jia)壓(ya)力(li)(li)(li)(li)的(de)(de)(de)作用(yong)，并(bing)且伴(ban)(ban)隨(sui)氣(qi)(qi)(qi)(qi)(qi)泡(pao)的(de)(de)(de)逐(zhu)(zhu)漸(jian)(jian)(jian)長大(da)(da)(da)，氣(qi)(qi)(qi)(qi)(qi)泡(pao)曲(qu)率半(ban)(ban)(ban)徑逐(zhu)(zhu)漸(jian)(jian)(jian)減小(xiao)(xiao)。彎(wan)曲(qu)液(ye)(ye)面(mian)(mian)(mian)(mian)附加(jia)壓(ya)力(li)(li)(li)(li)的(de)(de)(de)大(da)(da)(da)小(xiao)(xiao)與(yu)(yu)(yu)氣(qi)(qi)(qi)(qi)(qi)泡(pao)曲(qu)率半(ban)(ban)(ban)徑大(da)(da)(da)小(xiao)(xiao)成反(fan)比，因(yin)此伴(ban)(ban)隨(sui)毛(mao)(mao)細(xi)管(guan)(guan)下端(duan)(duan)端(duan)(duan)面(mian)(mian)(mian)(mian)和試樣(yang)液(ye)(ye)面(mian)(mian)(mian)(mian)之間接(jie)觸界面(mian)(mian)(mian)(mian)處逸(yi)出氣(qi)(qi)(qi)(qi)(qi)泡(pao)的(de)(de)(de)逐(zhu)(zhu)漸(jian)(jian)(jian)長大(da)(da)(da)、氣(qi)(qi)(qi)(qi)(qi)泡(pao)曲(qu)率半(ban)(ban)(ban)徑的(de)(de)(de)逐(zhu)(zhu)漸(jian)(jian)(jian)減小(xiao)(xiao)，彎(wan)曲(qu)液(ye)(ye)面(mian)(mian)(mian)(mian)附加(jia)壓(ya)力(li)(li)(li)(li)逐(zhu)(zhu)漸(jian)(jian)(jian)增(zeng)大(da)(da)(da)，氣(qi)(qi)(qi)(qi)(qi)泡(pao)逸(yi)出所需大(da)(da)(da)氣(qi)(qi)(qi)(qi)(qi)環境與(yu)(yu)(yu)表(biao)面(mian)(mian)(mian)(mian)張力(li)(li)(li)(li)測(ce)定(ding)裝(zhuang)(zhuang)置體(ti)系(xi)之間的(de)(de)(de)壓(ya)差(cha)(cha)逐(zhu)(zhu)漸(jian)(jian)(jian)增(zeng)大(da)(da)(da)，而當逸(yi)出氣(qi)(qi)(qi)(qi)(qi)泡(pao)長大(da)(da)(da)至曲(qu)率半(ban)(ban)(ban)徑恰好與(yu)(yu)(yu)毛(mao)(mao)細(xi)管(guan)(guan)半(ban)(ban)(ban)徑相(xiang)等時(shi)(shi)，氣(qi)(qi)(qi)(qi)(qi)泡(pao)即會以球狀離開毛(mao)(mao)細(xi)管(guan)(guan)端(duan)(duan)面(mian)(mian)(mian)(mian)，此時(shi)(shi)與(yu)(yu)(yu)表(biao)面(mian)(mian)(mian)(mian)張力(li)(li)(li)(li)測(ce)量裝(zhuang)(zhuang)置相(xiang)連(lian)的(de)(de)(de)微差(cha)(cha)壓(ya)差(cha)(cha)計中相(xiang)應出現最大(da)(da)(da)壓(ya)差(cha)(cha)讀(du)數(壓(ya)差(cha)(cha)的(de)(de)(de)絕對值)。

氣(qi)泡(pao)離(li)開毛(mao)細(xi)(xi)(xi)管(guan)端面(mian)進入表(biao)(biao)(biao)(biao)面(mian)張(zhang)力(li)測(ce)定裝置(zhi)(zhi)體(ti)(ti)(ti)系(xi)后(hou)，體(ti)(ti)(ti)系(xi)中的(de)(de)(de)(de)(de)壓(ya)力(li)增大(da)，微差(cha)壓(ya)差(cha)計(ji)(ji)(ji)示數(壓(ya)差(cha)的(de)(de)(de)(de)(de)絕對(dui)值(zhi))下(xia)降(jiang)至(zhi)某(mou)一(yi)值(zhi)。但只(zhi)要(yao)保持滴(di)(di)液(ye)漏斗持續(xu)緩慢滴(di)(di)液(ye)，在(zai)(zai)上一(yi)個氣(qi)泡(pao)逸出(chu)、微差(cha)壓(ya)差(cha)計(ji)(ji)(ji)示數降(jiang)至(zhi)某(mou)一(yi)值(zhi)后(hou)，體(ti)(ti)(ti)系(xi)中的(de)(de)(de)(de)(de)壓(ya)力(li)會再(zai)次(ci)(ci)逐漸降(jiang)低，一(yi)直到(dao)氣(qi)泡(pao)再(zai)次(ci)(ci)離(li)開毛(mao)細(xi)(xi)(xi)管(guan)端面(mian)時(shi)，微差(cha)壓(ya)差(cha)計(ji)(ji)(ji)示數再(zai)一(yi)次(ci)(ci)出(chu)現最(zui)大(da)值(zhi)。如此這(zhe)般(ban)，伴隨滴(di)(di)液(ye)漏斗的(de)(de)(de)(de)(de)不斷(duan)滴(di)(di)液(ye)，毛(mao)細(xi)(xi)(xi)管(guan)端面(mian)和試(shi)樣(yang)(yang)液(ye)面(mian)接觸界面(mian)處會不斷(duan)的(de)(de)(de)(de)(de)有氣(qi)泡(pao)長大(da)、逸出(chu)，微差(cha)壓(ya)差(cha)計(ji)(ji)(ji)示數發(fa)生周(zhou)而復(fu)始的(de)(de)(de)(de)(de)變(bian)化(hua)。控制測(ce)量(liang)(liang)體(ti)(ti)(ti)系(xi)的(de)(de)(de)(de)(de)溫度，并使(shi)用同(tong)一(yi)裝置(zhi)(zhi)(特別是要(yao)使(shi)用同(tong)一(yi)毛(mao)細(xi)(xi)(xi)管(guan))分別測(ce)量(liang)(liang)基(ji)準(zhun)試(shi)樣(yang)(yang)(一(yi)般(ban)可以使(shi)用純水)和待(dai)測(ce)定表(biao)(biao)(biao)(biao)面(mian)張(zhang)力(li)大(da)小的(de)(de)(de)(de)(de)試(shi)樣(yang)(yang)在(zai)(zai)相同(tong)測(ce)量(liang)(liang)溫度下(xia)對(dui)應(ying)氣(qi)泡(pao)剛好離(li)開毛(mao)細(xi)(xi)(xi)管(guan)端面(mian)時(shi)的(de)(de)(de)(de)(de)微差(cha)壓(ya)差(cha)計(ji)(ji)(ji)最(zui)大(da)讀數值(zhi)，查取(qu)相應(ying)溫度下(xia)基(ji)準(zhun)試(shi)樣(yang)(yang)表(biao)(biao)(biao)(biao)面(mian)張(zhang)力(li)值(zhi)，由(you)基(ji)準(zhun)試(shi)樣(yang)(yang)最(zui)大(da)壓(ya)差(cha)和待(dai)測(ce)試(shi)樣(yang)(yang)最(zui)大(da)壓(ya)差(cha)值(zhi)，即(ji)可計(ji)(ji)(ji)算得到(dao)待(dai)測(ce)試(shi)樣(yang)(yang)在(zai)(zai)相應(ying)溫度下(xia)的(de)(de)(de)(de)(de)表(biao)(biao)(biao)(biao)面(mian)張(zhang)力(li)值(zhi)。

在(zai)上(shang)述表面(mian)(mian)(mian)(mian)(mian)張(zhang)力測(ce)定(ding)過(guo)程中，需(xu)要確(que)保毛(mao)細(xi)(xi)管下(xia)端(duan)(duan)端(duan)(duan)面(mian)(mian)(mian)(mian)(mian)恰(qia)好與表面(mian)(mian)(mian)(mian)(mian)張(zhang)力測(ce)定(ding)裝置(zhi)裝樣(yang)(yang)(yang)試(shi)(shi)管內試(shi)(shi)樣(yang)(yang)(yang)液(ye)(ye)(ye)面(mian)(mian)(mian)(mian)(mian)相切：如果(guo)試(shi)(shi)樣(yang)(yang)(yang)液(ye)(ye)(ye)面(mian)(mian)(mian)(mian)(mian)高度(du)過(guo)低，毛(mao)細(xi)(xi)管端(duan)(duan)面(mian)(mian)(mian)(mian)(mian)未能與試(shi)(shi)樣(yang)(yang)(yang)液(ye)(ye)(ye)面(mian)(mian)(mian)(mian)(mian)接觸(chu)，在(zai)大(da)氣(qi)環境與表面(mian)(mian)(mian)(mian)(mian)張(zhang)力測(ce)定(ding)裝置(zhi)體系之間產生壓(ya)(ya)差時，空氣(qi)會(hui)直接從毛(mao)細(xi)(xi)管下(xia)端(duan)(duan)口逸(yi)出而(er)不會(hui)產生液(ye)(ye)(ye)泡(pao)(pao)；而(er)如果(guo)試(shi)(shi)樣(yang)(yang)(yang)液(ye)(ye)(ye)面(mian)(mian)(mian)(mian)(mian)過(guo)高，以至于毛(mao)細(xi)(xi)管下(xia)端(duan)(duan)端(duan)(duan)面(mian)(mian)(mian)(mian)(mian)的(de)(de)一部分插入試(shi)(shi)樣(yang)(yang)(yang)液(ye)(ye)(ye)面(mian)(mian)(mian)(mian)(mian)以下(xia)時，氣(qi)泡(pao)(pao)試(shi)(shi)圖由(you)毛(mao)細(xi)(xi)管端(duan)(duan)面(mian)(mian)(mian)(mian)(mian)和試(shi)(shi)樣(yang)(yang)(yang)液(ye)(ye)(ye)面(mian)(mian)(mian)(mian)(mian)接觸(chu)界面(mian)(mian)(mian)(mian)(mian)處逸(yi)出時不但(dan)需(xu)要克(ke)(ke)服(fu)彎曲液(ye)(ye)(ye)面(mian)(mian)(mian)(mian)(mian)附加壓(ya)(ya)力的(de)(de)作(zuo)用，還需(xu)要克(ke)(ke)服(fu)毛(mao)細(xi)(xi)管下(xia)端(duan)(duan)端(duan)(duan)面(mian)(mian)(mian)(mian)(mian)與試(shi)(shi)樣(yang)(yang)(yang)液(ye)(ye)(ye)面(mian)(mian)(mian)(mian)(mian)之間高度(du)差所(suo)對應(ying)的(de)(de)液(ye)(ye)(ye)體靜壓(ya)(ya)差的(de)(de)作(zuo)用，使得對應(ying)氣(qi)泡(pao)(pao)逸(yi)出離(li)開(kai)毛(mao)細(xi)(xi)管端(duan)(duan)面(mian)(mian)(mian)(mian)(mian)時微差壓(ya)(ya)差計最大(da)壓(ya)(ya)差讀數值(zhi)偏大(da)，導(dao)致待測(ce)試(shi)(shi)樣(yang)(yang)(yang)表面(mian)(mian)(mian)(mian)(mian)張(zhang)力測(ce)定(ding)值(zhi)的(de)(de)誤差，而(er)且液(ye)(ye)(ye)體靜壓(ya)(ya)差的(de)(de)作(zuo)用也會(hui)導(dao)致氣(qi)泡(pao)(pao)逸(yi)出離(li)開(kai)毛(mao)細(xi)(xi)管端(duan)(duan)面(mian)(mian)(mian)(mian)(mian)時難以保證為球狀(zhuang)，以至于滴液(ye)(ye)(ye)漏斗連續滴液(ye)(ye)(ye)、氣(qi)泡(pao)(pao)不斷(duan)逸(yi)出離(li)開(kai)毛(mao)細(xi)(xi)管端(duan)(duan)面(mian)(mian)(mian)(mian)(mian)時，微差壓(ya)(ya)差計最大(da)壓(ya)(ya)差讀數的(de)(de)重(zhong)現性變(bian)差，導(dao)致待測(ce)試(shi)(shi)樣(yang)(yang)(yang)表面(mian)(mian)(mian)(mian)(mian)張(zhang)力測(ce)定(ding)值(zhi)的(de)(de)誤差。

在現有液體表面(mian)張力試(shi)驗裝(zhuang)置中，通常使用上部帶磨口或圓形口的試(shi)管作為裝(zhuang)樣(yang)試(shi)管，如(ru)圖2所示。

使(shi)用(yong)這種(zhong)結構的裝(zhuang)(zhuang)樣(yang)(yang)試(shi)(shi)(shi)(shi)管(guan)(guan)(guan)(guan)進行液(ye)體表面(mian)(mian)(mian)(mian)(mian)張力測(ce)定(ding)(ding)試(shi)(shi)(shi)(shi)驗時(shi)，需要通過(guo)插毛(mao)(mao)細管(guan)(guan)(guan)(guan)口(kou)加(jia)(jia)入待測(ce)試(shi)(shi)(shi)(shi)樣(yang)(yang)并用(yong)滴管(guan)(guan)(guan)(guan)通過(guo)插毛(mao)(mao)細管(guan)(guan)(guan)(guan)口(kou)加(jia)(jia)入試(shi)(shi)(shi)(shi)樣(yang)(yang)或取(qu)(qu)出試(shi)(shi)(shi)(shi)樣(yang)(yang)調節(jie)(jie)裝(zhuang)(zhuang)樣(yang)(yang)試(shi)(shi)(shi)(shi)管(guan)(guan)(guan)(guan)內試(shi)(shi)(shi)(shi)樣(yang)(yang)液(ye)面(mian)(mian)(mian)(mian)(mian)高度(du)，使(shi)得(de)毛(mao)(mao)細管(guan)(guan)(guan)(guan)下端(duan)端(duan)面(mian)(mian)(mian)(mian)(mian)與試(shi)(shi)(shi)(shi)樣(yang)(yang)管(guan)(guan)(guan)(guan)內液(ye)面(mian)(mian)(mian)(mian)(mian)相切。但在調節(jie)(jie)裝(zhuang)(zhuang)樣(yang)(yang)試(shi)(shi)(shi)(shi)管(guan)(guan)(guan)(guan)內液(ye)面(mian)(mian)(mian)(mian)(mian)高度(du)時(shi)，需要取(qu)(qu)走(zou)毛(mao)(mao)細管(guan)(guan)(guan)(guan)而無法在調節(jie)(jie)試(shi)(shi)(shi)(shi)樣(yang)(yang)液(ye)面(mian)(mian)(mian)(mian)(mian)高度(du)的過(guo)程(cheng)中觀測(ce)到毛(mao)(mao)細管(guan)(guan)(guan)(guan)端(duan)面(mian)(mian)(mian)(mian)(mian)相對(dui)于試(shi)(shi)(shi)(shi)樣(yang)(yang)液(ye)面(mian)(mian)(mian)(mian)(mian)的位置(zhi)，每次(ci)加(jia)(jia)入試(shi)(shi)(shi)(shi)樣(yang)(yang)或取(qu)(qu)走(zou)試(shi)(shi)(shi)(shi)樣(yang)(yang)量會(hui)有一定(ding)(ding)的盲目(mu)性(xing)，因此需要經過(guo)多次(ci)嘗試(shi)(shi)(shi)(shi)后(hou)才能(neng)使(shi)得(de)毛(mao)(mao)細管(guan)(guan)(guan)(guan)下端(duan)端(duan)面(mian)(mian)(mian)(mian)(mian)與試(shi)(shi)(shi)(shi)樣(yang)(yang)管(guan)(guan)(guan)(guan)內液(ye)面(mian)(mian)(mian)(mian)(mian)相切，試(shi)(shi)(shi)(shi)樣(yang)(yang)液(ye)面(mian)(mian)(mian)(mian)(mian)調節(jie)(jie)過(guo)程(cheng)繁瑣。

為了能夠方便地調節(jie)液體表面張力試(shi)驗裝置(zhi)裝樣(yang)試(shi)管(guan)中(zhong)的(de)液面高度(du)，現有(you)技(ji)術中(zhong)也有(you)人(ren)采(cai)用如圖3或(huo)圖4所(suo)示的(de)裝樣(yang)試(shi)管(guan)中(zhong)。

圖(tu)3所示液(ye)體(ti)表面(mian)(mian)(mian)(mian)張力(li)試(shi)(shi)(shi)驗裝(zhuang)置(zhi)裝(zhuang)樣(yang)(yang)(yang)(yang)(yang)試(shi)(shi)(shi)管(guan)(guan)的(de)主要特征(zheng)是裝(zhuang)樣(yang)(yang)(yang)(yang)(yang)試(shi)(shi)(shi)管(guan)(guan)下(xia)部有一(yi)活(huo)(huo)塞(sai)。使用時(shi)先將待測試(shi)(shi)(shi)樣(yang)(yang)(yang)(yang)(yang)由插(cha)毛(mao)(mao)細(xi)管(guan)(guan)口加入(ru)，加入(ru)試(shi)(shi)(shi)樣(yang)(yang)(yang)(yang)(yang)量要能夠保證插(cha)入(ru)毛(mao)(mao)細(xi)管(guan)(guan)后(hou)毛(mao)(mao)細(xi)管(guan)(guan)下(xia)端(duan)(duan)端(duan)(duan)面(mian)(mian)(mian)(mian)能夠在裝(zhuang)樣(yang)(yang)(yang)(yang)(yang)試(shi)(shi)(shi)管(guan)(guan)內(nei)待測試(shi)(shi)(shi)樣(yang)(yang)(yang)(yang)(yang)液(ye)面(mian)(mian)(mian)(mian)以(yi)下(xia)。插(cha)入(ru)毛(mao)(mao)細(xi)管(guan)(guan)后(hou)，逐漸開啟裝(zhuang)樣(yang)(yang)(yang)(yang)(yang)試(shi)(shi)(shi)管(guan)(guan)下(xia)端(duan)(duan)的(de)活(huo)(huo)塞(sai)，緩慢(man)放出裝(zhuang)樣(yang)(yang)(yang)(yang)(yang)試(shi)(shi)(shi)管(guan)(guan)中的(de)試(shi)(shi)(shi)樣(yang)(yang)(yang)(yang)(yang)，試(shi)(shi)(shi)樣(yang)(yang)(yang)(yang)(yang)液(ye)面(mian)(mian)(mian)(mian)降低至一(yi)定(ding)高度時(shi)，毛(mao)(mao)細(xi)管(guan)(guan)下(xia)端(duan)(duan)端(duan)(duan)面(mian)(mian)(mian)(mian)恰好與試(shi)(shi)(shi)樣(yang)(yang)(yang)(yang)(yang)液(ye)面(mian)(mian)(mian)(mian)接觸，并且由于(yu)毛(mao)(mao)細(xi)管(guan)(guan)端(duan)(duan)面(mian)(mian)(mian)(mian)與試(shi)(shi)(shi)樣(yang)(yang)(yang)(yang)(yang)之間的(de)潤濕效應，通(tong)過(guo)活(huo)(huo)塞(sai)緩慢(man)放出裝(zhuang)樣(yang)(yang)(yang)(yang)(yang)試(shi)(shi)(shi)管(guan)(guan)中的(de)試(shi)(shi)(shi)樣(yang)(yang)(yang)(yang)(yang)至試(shi)(shi)(shi)樣(yang)(yang)(yang)(yang)(yang)高度略低于(yu)毛(mao)(mao)細(xi)管(guan)(guan)下(xia)端(duan)(duan)端(duan)(duan)面(mian)(mian)(mian)(mian)時(shi)，試(shi)(shi)(shi)樣(yang)(yang)(yang)(yang)(yang)會微(wei)微(wei)凸起并保持(chi)與毛(mao)(mao)細(xi)管(guan)(guan)端(duan)(duan)面(mian)(mian)(mian)(mian)的(de)接觸，以(yi)保證毛(mao)(mao)細(xi)管(guan)(guan)下(xia)端(duan)(duan)端(duan)(duan)面(mian)(mian)(mian)(mian)與試(shi)(shi)(shi)樣(yang)(yang)(yang)(yang)(yang)液(ye)面(mian)(mian)(mian)(mian)相(xiang)切(qie)。

為了(le)保(bao)證(zheng)裝(zhuang)樣(yang)(yang)(yang)試(shi)(shi)管(guan)下(xia)部活(huo)塞使用靈活(huo)和良好的(de)(de)(de)(de)密(mi)封性(xing)，以(yi)免(mian)裝(zhuang)樣(yang)(yang)(yang)試(shi)(shi)管(guan)浸入恒溫浴槽內恒溫時浴槽中(zhong)的(de)(de)(de)(de)水通過活(huo)塞滲入裝(zhuang)樣(yang)(yang)(yang)試(shi)(shi)管(guan)內污(wu)(wu)染待測試(shi)(shi)樣(yang)(yang)(yang)，通常需要在活(huo)塞處(chu)涂(tu)抹密(mi)封油(you)(you)脂。而涂(tu)抹在活(huo)塞上(shang)的(de)(de)(de)(de)油(you)(you)脂難免(mian)會(hui)與(yu)待測試(shi)(shi)樣(yang)(yang)(yang)接觸(chu)，而一旦有少量油(you)(you)脂溶(rong)入待測試(shi)(shi)樣(yang)(yang)(yang)，即(ji)會(hui)引起試(shi)(shi)樣(yang)(yang)(yang)表(biao)面(mian)(mian)張(zhang)(zhang)力(li)的(de)(de)(de)(de)改變，導致(zhi)試(shi)(shi)樣(yang)(yang)(yang)表(biao)面(mian)(mian)張(zhang)(zhang)力(li)測量誤差(cha)(cha)。而如果溶(rong)入的(de)(de)(de)(de)油(you)(you)脂污(wu)(wu)染毛(mao)細管(guan)下(xia)端(duan)端(duan)面(mian)(mian)，則(ze)難以(yi)保(bao)證(zheng)氣(qi)泡以(yi)規整的(de)(de)(de)(de)球狀從毛(mao)細管(guan)下(xia)端(duan)端(duan)面(mian)(mian)和試(shi)(shi)樣(yang)(yang)(yang)液(ye)面(mian)(mian)的(de)(de)(de)(de)接觸(chu)界面(mian)(mian)處(chu)逸出(chu)并離開(kai)毛(mao)細管(guan)端(duan)面(mian)(mian)，有時也(ye)會(hui)導致(zhi)氣(qi)泡以(yi)連珠泡的(de)(de)(de)(de)形式逸出(chu)，導致(zhi)最(zui)大壓差(cha)(cha)讀數的(de)(de)(de)(de)重現性(xing)變差(cha)(cha)，試(shi)(shi)樣(yang)(yang)(yang)表(biao)面(mian)(mian)張(zhang)(zhang)力(li)測量產(chan)生(sheng)誤差(cha)(cha)。顯然，上(shang)述帶有下(xia)部活(huo)塞的(de)(de)(de)(de)液(ye)體(ti)表(biao)面(mian)(mian)張(zhang)(zhang)力(li)試(shi)(shi)驗裝(zhuang)置裝(zhuang)樣(yang)(yang)(yang)試(shi)(shi)管(guan)，并不是(shi)一種(zhong)合理的(de)(de)(de)(de)結(jie)構(gou)。

圖(tu)4所示(shi)最大氣泡法測(ce)定液體表面(mian)張力(li)試(shi)(shi)驗裝(zhuang)置裝(zhuang)樣(yang)試(shi)(shi)管(guan)結構，其主要特征是裝(zhuang)樣(yang)試(shi)(shi)管(guan)下部有一(yi)彎管(guan)，通(tong)過彎管(guan)口部加入或取出(chu)試(shi)(shi)樣(yang)，以調(diao)節裝(zhuang)樣(yang)試(shi)(shi)管(guan)內待測(ce)試(shi)(shi)樣(yang)液面(mian)高度。

使用(yong)圖4所示下部帶彎(wan)管(guan)(guan)的裝(zhuang)(zhuang)樣(yang)(yang)試(shi)(shi)管(guan)(guan)進行液(ye)體表(biao)面(mian)張力測(ce)定試(shi)(shi)驗時，先經插(cha)毛細(xi)管(guan)(guan)口(kou)或(huo)彎(wan)管(guan)(guan)口(kou)部加入待測(ce)試(shi)(shi)樣(yang)(yang)至插(cha)入毛細(xi)管(guan)(guan)后裝(zhuang)(zhuang)樣(yang)(yang)試(shi)(shi)管(guan)(guan)內試(shi)(shi)樣(yang)(yang)液(ye)面(mian)高(gao)(gao)度(du)與毛細(xi)管(guan)(guan)下端斷面(mian)基(ji)本相齊。視毛細(xi)管(guan)(guan)端面(mian)與試(shi)(shi)樣(yang)(yang)液(ye)面(mian)的相對高(gao)(gao)度(du)，通(tong)過彎(wan)管(guan)(guan)口(kou)部用(yong)滴管(guan)(guan)向裝(zhuang)(zhuang)樣(yang)(yang)試(shi)(shi)管(guan)(guan)內加入或(huo)取出待測(ce)試(shi)(shi)樣(yang)(yang)調節裝(zhuang)(zhuang)樣(yang)(yang)試(shi)(shi)管(guan)(guan)內試(shi)(shi)樣(yang)(yang)液(ye)面(mian)高(gao)(gao)度(du)，使得毛細(xi)管(guan)(guan)端面(mian)與試(shi)(shi)樣(yang)(yang)液(ye)面(mian)正好相切。

但(dan)這種帶(dai)彎(wan)(wan)管(guan)(guan)(guan)(guan)(guan)的(de)裝(zhuang)(zhuang)樣(yang)試(shi)(shi)(shi)管(guan)(guan)(guan)(guan)(guan)也存在(zai)(zai)若(ruo)干(gan)缺陷：使用這種結(jie)(jie)構(gou)的(de)裝(zhuang)(zhuang)樣(yang)試(shi)(shi)(shi)管(guan)(guan)(guan)(guan)(guan)進(jin)行(xing)液(ye)體(ti)(ti)表面(mian)(mian)(mian)(mian)(mian)(mian)(mian)張(zhang)(zhang)力(li)(li)測定試(shi)(shi)(shi)驗時(shi)，雖經耐心的(de)試(shi)(shi)(shi)樣(yang)液(ye)面(mian)(mian)(mian)(mian)(mian)(mian)(mian)高(gao)度(du)(du)調節至毛細(xi)管(guan)(guan)(guan)(guan)(guan)端(duan)面(mian)(mian)(mian)(mian)(mian)(mian)(mian)與試(shi)(shi)(shi)樣(yang)液(ye)面(mian)(mian)(mian)(mian)(mian)(mian)(mian)相(xiang)切(qie)(qie)，但(dan)在(zai)(zai)測定前必須塞(sai)(sai)緊彎(wan)(wan)管(guan)(guan)(guan)(guan)(guan)口(kou)部的(de)活(huo)塞(sai)(sai)，而在(zai)(zai)塞(sai)(sai)活(huo)塞(sai)(sai)的(de)過程(cheng)中(zhong)彎(wan)(wan)管(guan)(guan)(guan)(guan)(guan)內(nei)(nei)(nei)(nei)的(de)一部分試(shi)(shi)(shi)樣(yang)會(hui)被(bei)頂入(ru)試(shi)(shi)(shi)樣(yang)管(guan)(guan)(guan)(guan)(guan)主體(ti)(ti)內(nei)(nei)(nei)(nei)導(dao)致試(shi)(shi)(shi)樣(yang)液(ye)面(mian)(mian)(mian)(mian)(mian)(mian)(mian)高(gao)度(du)(du)的(de)上升，毛細(xi)管(guan)(guan)(guan)(guan)(guan)下(xia)端(duan)端(duan)面(mian)(mian)(mian)(mian)(mian)(mian)(mian)無法保持(chi)和(he)試(shi)(shi)(shi)樣(yang)液(ye)面(mian)(mian)(mian)(mian)(mian)(mian)(mian)相(xiang)切(qie)(qie)而會(hui)有部分插入(ru)試(shi)(shi)(shi)樣(yang)液(ye)面(mian)(mian)(mian)(mian)(mian)(mian)(mian)內(nei)(nei)(nei)(nei)。另外(wai)，在(zai)(zai)塞(sai)(sai)入(ru)活(huo)塞(sai)(sai)時(shi)，很可能會(hui)在(zai)(zai)活(huo)塞(sai)(sai)和(he)彎(wan)(wan)管(guan)(guan)(guan)(guan)(guan)口(kou)部的(de)試(shi)(shi)(shi)樣(yang)液(ye)面(mian)(mian)(mian)(mian)(mian)(mian)(mian)之(zhi)間有一小段空(kong)(kong)氣(qi)柱(zhu)，而空(kong)(kong)氣(qi)的(de)易(yi)膨(peng)脹特性，導(dao)致裝(zhuang)(zhuang)樣(yang)試(shi)(shi)(shi)管(guan)(guan)(guan)(guan)(guan)內(nei)(nei)(nei)(nei)部為(wei)負壓時(shi)，彎(wan)(wan)管(guan)(guan)(guan)(guan)(guan)口(kou)部的(de)空(kong)(kong)氣(qi)膨(peng)脹，試(shi)(shi)(shi)樣(yang)液(ye)面(mian)(mian)(mian)(mian)(mian)(mian)(mian)下(xia)降，彎(wan)(wan)管(guan)(guan)(guan)(guan)(guan)內(nei)(nei)(nei)(nei)的(de)試(shi)(shi)(shi)樣(yang)轉移至裝(zhuang)(zhuang)樣(yang)試(shi)(shi)(shi)管(guan)(guan)(guan)(guan)(guan)主體(ti)(ti)內(nei)(nei)(nei)(nei)，試(shi)(shi)(shi)樣(yang)液(ye)面(mian)(mian)(mian)(mian)(mian)(mian)(mian)抬升并超過毛細(xi)管(guan)(guan)(guan)(guan)(guan)下(xia)端(duan)端(duan)面(mian)(mian)(mian)(mian)(mian)(mian)(mian)，氣(qi)泡從毛細(xi)管(guan)(guan)(guan)(guan)(guan)下(xia)端(duan)逸出(chu)的(de)最大壓差示數偏大，導(dao)致試(shi)(shi)(shi)樣(yang)表面(mian)(mian)(mian)(mian)(mian)(mian)(mian)張(zhang)(zhang)力(li)(li)測量值產(chan)生誤(wu)差。再者，由于表面(mian)(mian)(mian)(mian)(mian)(mian)(mian)張(zhang)(zhang)力(li)(li)大小與溫(wen)(wen)(wen)(wen)(wen)度(du)(du)有關，測量液(ye)體(ti)(ti)表面(mian)(mian)(mian)(mian)(mian)(mian)(mian)張(zhang)(zhang)力(li)(li)時(shi)需(xu)要(yao)對待測試(shi)(shi)(shi)樣(yang)加以(yi)恒(heng)溫(wen)(wen)(wen)(wen)(wen)控(kong)制(zhi)，如果所(suo)用裝(zhuang)(zhuang)樣(yang)試(shi)(shi)(shi)管(guan)(guan)(guan)(guan)(guan)為(wei)單壁而不是(shi)可以(yi)通(tong)恒(heng)溫(wen)(wen)(wen)(wen)(wen)水(shui)以(yi)控(kong)制(zhi)試(shi)(shi)(shi)樣(yang)溫(wen)(wen)(wen)(wen)(wen)度(du)(du)的(de)帶(dai)恒(heng)溫(wen)(wen)(wen)(wen)(wen)水(shui)夾套試(shi)(shi)(shi)樣(yang)管(guan)(guan)(guan)(guan)(guan)，進(jin)行(xing)表面(mian)(mian)(mian)(mian)(mian)(mian)(mian)張(zhang)(zhang)力(li)(li)測量時(shi)，需(xu)要(yao)將試(shi)(shi)(shi)樣(yang)液(ye)面(mian)(mian)(mian)(mian)(mian)(mian)(mian)以(yi)下(xia)部位的(de)試(shi)(shi)(shi)樣(yang)管(guan)(guan)(guan)(guan)(guan)主體(ti)(ti)連同下(xia)部彎(wan)(wan)管(guan)(guan)(guan)(guan)(guan)浸入(ru)恒(heng)溫(wen)(wen)(wen)(wen)(wen)浴(yu)槽水(shui)液(ye)面(mian)(mian)(mian)(mian)(mian)(mian)(mian)以(yi)下(xia)進(jin)行(xing)恒(heng)溫(wen)(wen)(wen)(wen)(wen)控(kong)制(zhi)，但(dan)為(wei)了避(bi)免在(zai)(zai)塞(sai)(sai)入(ru)活(huo)塞(sai)(sai)后(hou)彎(wan)(wan)管(guan)(guan)(guan)(guan)(guan)口(kou)部活(huo)塞(sai)(sai)和(he)試(shi)(shi)(shi)樣(yang)液(ye)面(mian)(mian)(mian)(mian)(mian)(mian)(mian)之(zhi)間出(chu)現空(kong)(kong)氣(qi)柱(zhu)，彎(wan)(wan)管(guan)(guan)(guan)(guan)(guan)口(kou)高(gao)度(du)(du)一般(ban)是(shi)略高(gao)于毛細(xi)管(guan)(guan)(guan)(guan)(guan)下(xia)端(duan)端(duan)面(mian)(mian)(mian)(mian)(mian)(mian)(mian)高(gao)度(du)(du)，將裝(zhuang)(zhuang)樣(yang)試(shi)(shi)(shi)管(guan)(guan)(guan)(guan)(guan)浸入(ru)恒(heng)溫(wen)(wen)(wen)(wen)(wen)浴(yu)槽中(zhong)進(jin)行(xing)恒(heng)溫(wen)(wen)(wen)(wen)(wen)時(shi)，又需(xu)要(yao)將試(shi)(shi)(shi)樣(yang)液(ye)面(mian)(mian)(mian)(mian)(mian)(mian)(mian)，也就是(shi)毛細(xi)管(guan)(guan)(guan)(guan)(guan)下(xia)端(duan)端(duan)面(mian)(mian)(mian)(mian)(mian)(mian)(mian)以(yi)下(xia)部位浸入(ru)恒(heng)溫(wen)(wen)(wen)(wen)(wen)水(shui)液(ye)面(mian)(mian)(mian)(mian)(mian)(mian)(mian)以(yi)下(xia)，彎(wan)(wan)管(guan)(guan)(guan)(guan)(guan)口(kou)會(hui)非常(chang)接近恒(heng)溫(wen)(wen)(wen)(wen)(wen)水(shui)液(ye)面(mian)(mian)(mian)(mian)(mian)(mian)(mian)而容易(yi)被(bei)恒(heng)溫(wen)(wen)(wen)(wen)(wen)浴(yu)槽內(nei)(nei)(nei)(nei)的(de)水(shui)污染，一旦進(jin)一步污染到(dao)裝(zhuang)(zhuang)樣(yang)試(shi)(shi)(shi)管(guan)(guan)(guan)(guan)(guan)內(nei)(nei)(nei)(nei)的(de)試(shi)(shi)(shi)樣(yang)，液(ye)體(ti)(ti)表面(mian)(mian)(mian)(mian)(mian)(mian)(mian)張(zhang)(zhang)力(li)(li)測量結(jie)(jie)果就會(hui)產(chan)生誤(wu)差。因(yin)此，下(xia)部帶(dai)彎(wan)(wan)管(guan)(guan)(guan)(guan)(guan)的(de)裝(zhuang)(zhuang)樣(yang)試(shi)(shi)(shi)管(guan)(guan)(guan)(guan)(guan)，也不是(shi)一種很好(hao)的(de)液(ye)體(ti)(ti)表面(mian)(mian)(mian)(mian)(mian)(mian)(mian)張(zhang)(zhang)力(li)(li)試(shi)(shi)(shi)驗裝(zhuang)(zhuang)樣(yang)試(shi)(shi)(shi)管(guan)(guan)(guan)(guan)(guan)結(jie)(jie)構(gou)。

技術實現要素：

本實(shi)用新型的(de)目的(de)在于針對現有最(zui)(zui)大氣(qi)泡法測定(ding)液體(ti)(ti)表(biao)面張(zhang)力試(shi)(shi)驗裝樣試(shi)(shi)管試(shi)(shi)樣液面調(diao)節過程中(zhong)存在的(de)問題，提供一種可以方便地(di)進行試(shi)(shi)樣液面高度調(diao)節的(de)最(zui)(zui)大氣(qi)泡法測定(ding)液體(ti)(ti)表(biao)面張(zhang)力試(shi)(shi)驗裝樣試(shi)(shi)管結構(gou)。

本實用(yong)新型的目的是通過以下技術方(fang)案來(lai)實現(xian)的：一(yi)種最大氣泡(pao)法(fa)測定液體表(biao)面張(zhang)力試(shi)(shi)(shi)驗裝樣試(shi)(shi)(shi)管(guan)，試(shi)(shi)(shi)管(guan)包(bao)含插毛細管(guan)口、與壓差產生(sheng)裝置和(he)壓差測量裝置連接的支(zhi)管(guan)和(he)用(yong)于(yu)滴加或吸取試(shi)(shi)(shi)樣調節(jie)試(shi)(shi)(shi)管(guan)內液面高度的側管(guan)。

進(jin)一步地，加工試管所用材料(liao)(liao)為無機(ji)材料(liao)(liao)、金(jin)屬(shu)材料(liao)(liao)或有機(ji)材料(liao)(liao)，所述無機(ji)材料(liao)(liao)選自(zi)玻璃(li)、石(shi)英、陶瓷，所述金(jin)屬(shu)材料(liao)(liao)選自(zi)銅(tong)、銅(tong)合金(jin)、不(bu)銹(xiu)鋼，所述有機(ji)材料(liao)(liao)選自(zi)塑料(liao)(liao)、樹脂。

進一步地(di)，側管傾斜角(jiao)度可以是(shi)0～90°之間的(de)任意角(jiao)度。

進一步地，側(ce)(ce)管長度可以是(shi)任意尺寸，但需保(bao)證(zheng)裝樣試(shi)(shi)管浸入恒(heng)溫浴(yu)槽內(nei)(nei)至試(shi)(shi)管內(nei)(nei)試(shi)(shi)樣液面在浴(yu)槽內(nei)(nei)水液面以下時，側(ce)(ce)管口仍能保(bao)持在浴(yu)槽水液面以上。

進一步(bu)地，側管與裝樣(yang)(yang)試管主體連接(jie)(jie)位置需保證試管內試樣(yang)(yang)液面(mian)高度(du)調整至(zhi)正好(hao)與所插(cha)入的毛細管下端端面(mian)相切時(shi)，側管與裝樣(yang)(yang)試管主體連接(jie)(jie)口整體或至(zhi)少(shao)有(you)一部分(fen)位于試管內試樣(yang)(yang)液面(mian)以(yi)上。

進一(yi)步地，試管插(cha)毛細管口和側管口內壁為(wei)磨砂狀或(huo)光潔表面狀。

進一步地，裝樣試管(guan)主(zhu)體可以是(shi)(shi)單壁，也可以是(shi)(shi)內部通恒溫循(xun)環(huan)水的雙壁夾(jia)套(tao)結構。

本實(shi)用(yong)(yong)新型(xing)(xing)的有(you)益效果(guo)是：本實(shi)用(yong)(yong)新型(xing)(xing)裝(zhuang)(zhuang)樣(yang)試(shi)(shi)(shi)管包含插毛細管口、與壓差產生裝(zhuang)(zhuang)置和壓差測量裝(zhuang)(zhuang)置連接的支管和用(yong)(yong)于滴(di)加(jia)或吸(xi)取試(shi)(shi)(shi)樣(yang)調節試(shi)(shi)(shi)管內液面(mian)(mian)(mian)高(gao)度(du)的側管。采用(yong)(yong)本實(shi)用(yong)(yong)新型(xing)(xing)提供的裝(zhuang)(zhuang)樣(yang)試(shi)(shi)(shi)管結構，可以(yi)方(fang)便(bian)地進行試(shi)(shi)(shi)樣(yang)液面(mian)(mian)(mian)高(gao)度(du)調節，確(que)保插入毛細管下端端面(mian)(mian)(mian)與裝(zhuang)(zhuang)樣(yang)試(shi)(shi)(shi)管內試(shi)(shi)(shi)樣(yang)液面(mian)(mian)(mian)相切，提高(gao)液體表(biao)面(mian)(mian)(mian)張力測定的準確(que)性(xing)。

附圖說明

圖1為帶測管的最大(da)氣(qi)泡(pao)法測定液體(ti)表面張力試驗(yan)裝(zhuang)樣試管；

圖2為通過插毛細管(guan)口調節試樣液面高度的最大氣泡法測定(ding)液體表(biao)面張力試驗裝樣試管(guan)；

圖3為(wei)下部帶活塞的最(zui)大氣(qi)泡法測(ce)定液體表(biao)面張(zhang)力試(shi)驗裝(zhuang)樣試(shi)管；

圖(tu)4為下部帶彎管(guan)的最大氣泡法(fa)測定液體(ti)表面張力試(shi)驗裝樣試(shi)管(guan)；

圖(tu)5為(wei)應用(yong)本實用(yong)新(xin)型提供的單(dan)壁帶側管裝(zhuang)(zhuang)樣試管進行(xing)最大氣泡法測定液體(ti)表面張力試驗裝(zhuang)(zhuang)置(zhi)示意圖(tu)；

圖6為應用本實(shi)用新型提供的內部可以通恒溫循環水的雙壁夾套結構(gou)帶側管裝樣(yang)試(shi)管進行最大氣泡法(fa)測定液(ye)體表面張力(li)試(shi)驗裝置(zhi)示(shi)意圖；

圖7為現有通(tong)過插毛細管口調(diao)節(jie)試樣液面高度的最大氣泡法測(ce)定(ding)液體表面張力(li)試驗試驗裝置示意圖；

圖8為現有通過下部(bu)活(huo)塞調節(jie)試(shi)樣液面(mian)高(gao)度的最大氣(qi)泡法測定(ding)液體表面(mian)張力試(shi)驗試(shi)驗裝置示意圖；

圖9為現有通(tong)過下部彎管(guan)調(diao)節(jie)試(shi)(shi)樣液(ye)面高(gao)度的(de)最(zui)大氣泡(pao)法測(ce)定(ding)液(ye)體表面張力試(shi)(shi)驗(yan)試(shi)(shi)驗(yan)裝置示意圖；

圖中(zhong)，滴液漏(lou)斗1、燒杯2、微(wei)差壓差計(ji)3、毛細(xi)(xi)管(guan)4、裝樣試(shi)管(guan)5、恒溫浴槽6、側管(guan)7、恒溫水進口(kou)(kou)(kou)8、恒溫水出口(kou)(kou)(kou)9、支管(guan)10、插毛細(xi)(xi)管(guan)口(kou)(kou)(kou)11、彎管(guan)口(kou)(kou)(kou)部12。

具體實施方式

下面結合附圖和具(ju)體實施(shi)例對本實用新型作(zuo)進一步(bu)詳(xiang)細說明。

如圖1所示，本實用新(xin)型(xing)提供的(de)一種最大氣泡法測(ce)定液體表面張力試驗裝(zhuang)(zhuang)樣(yang)試管(guan)(guan)，包(bao)含插(cha)毛(mao)細管(guan)(guan)口11、與壓差(cha)產(chan)生裝(zhuang)(zhuang)置和(he)壓差(cha)測(ce)量裝(zhuang)(zhuang)置連接的(de)支(zhi)管(guan)(guan)10和(he)用于滴加或吸取試樣(yang)調節試管(guan)(guan)內液面高度的(de)側管(guan)(guan)7。

進一步地，加(jia)工裝(zhuang)樣試(shi)管(guan)5所(suo)(suo)用材(cai)料(liao)為無(wu)機(ji)材(cai)料(liao)、金(jin)屬(shu)(shu)材(cai)料(liao)或(huo)有機(ji)材(cai)料(liao)，所(suo)(suo)述無(wu)機(ji)材(cai)料(liao)選(xuan)自玻(bo)璃、石英、陶(tao)瓷，所(suo)(suo)述金(jin)屬(shu)(shu)材(cai)料(liao)選(xuan)自銅(tong)、銅(tong)合金(jin)、不銹鋼，所(suo)(suo)述有機(ji)材(cai)料(liao)選(xuan)自塑料(liao)、樹脂。

進一步地，側管7傾斜角度可以是0～90°之間的任意角度。

進一步地(di)，側(ce)管(guan)7長度(du)可(ke)以(yi)是任(ren)意尺寸(cun)，但需保(bao)證裝(zhuang)樣試管(guan)5浸入恒(heng)溫浴槽1內至試管(guan)內試樣液(ye)面(mian)(mian)在浴槽內水液(ye)面(mian)(mian)以(yi)下時，側(ce)管(guan)口仍(reng)能(neng)保(bao)持在浴槽水液(ye)面(mian)(mian)以(yi)上。

進一(yi)步地(di)，側(ce)管(guan)7與裝(zhuang)樣(yang)試(shi)管(guan)5主(zhu)體連接(jie)位(wei)置需保(bao)證(zheng)試(shi)管(guan)內(nei)試(shi)樣(yang)液面(mian)高度調整(zheng)至正好與所插(cha)入的毛細管(guan)4下端(duan)端(duan)面(mian)相切時(shi)，側(ce)管(guan)7與裝(zhuang)樣(yang)試(shi)管(guan)主(zhu)體連接(jie)口(kou)整(zheng)體或至少有一(yi)部分位(wei)于試(shi)管(guan)內(nei)試(shi)樣(yang)液面(mian)以上。

進一(yi)步地，試管(guan)(guan)插(cha)毛細管(guan)(guan)口和側管(guan)(guan)口內壁為磨砂狀(zhuang)或(huo)光(guang)潔表面(mian)狀(zhuang)。

進一步地，裝樣試管主(zhu)體可以(yi)是單壁(bi)，也可以(yi)是內部(bu)通(tong)恒溫循環(huan)水(shui)的雙(shuang)壁(bi)夾套結構。

如圖(tu)5所(suo)示，打(da)開恒(heng)溫(wen)(wen)浴槽(cao)6和微差(cha)(cha)壓差(cha)(cha)計3電源。設置(zhi)恒(heng)溫(wen)(wen)浴槽(cao)6控制溫(wen)(wen)度為表面(mian)(mian)(mian)(mian)(mian)(mian)張力測(ce)定(ding)試(shi)(shi)(shi)(shi)(shi)驗所(suo)需溫(wen)(wen)度。用去(qu)(qu)離子(zi)水(shui)(shui)(shui)(shui)仔細洗(xi)滌裝(zhuang)樣(yang)(yang)(yang)(yang)試(shi)(shi)(shi)(shi)(shi)管(guan)(guan)(guan)(guan)(guan)5內(nei)表面(mian)(mian)(mian)(mian)(mian)(mian)及(ji)毛(mao)(mao)細管(guan)(guan)(guan)(guan)(guan)4內(nei)、外(wai)表面(mian)(mian)(mian)(mian)(mian)(mian)。特別在(zai)洗(xi)滌毛(mao)(mao)細管(guan)(guan)(guan)(guan)(guan)4內(nei)表面(mian)(mian)(mian)(mian)(mian)(mian)時，用洗(xi)耳球吸(xi)(xi)、擠至少三次，將毛(mao)(mao)細管(guan)(guan)(guan)(guan)(guan)4內(nei)表面(mian)(mian)(mian)(mian)(mian)(mian)洗(xi)滌干凈。將毛(mao)(mao)細管(guan)(guan)(guan)(guan)(guan)4插入裝(zhuang)樣(yang)(yang)(yang)(yang)試(shi)(shi)(shi)(shi)(shi)管(guan)(guan)(guan)(guan)(guan)5并塞(sai)(sai)緊(jin)。經側(ce)(ce)(ce)管(guan)(guan)(guan)(guan)(guan)口(kou)加(jia)入去(qu)(qu)離子(zi)水(shui)(shui)(shui)(shui)至裝(zhuang)樣(yang)(yang)(yang)(yang)試(shi)(shi)(shi)(shi)(shi)管(guan)(guan)(guan)(guan)(guan)5內(nei)水(shui)(shui)(shui)(shui)液(ye)面(mian)(mian)(mian)(mian)(mian)(mian)與(yu)(yu)毛(mao)(mao)細管(guan)(guan)(guan)(guan)(guan)4下(xia)端(duan)(duan)(duan)端(duan)(duan)(duan)面(mian)(mian)(mian)(mian)(mian)(mian)基(ji)本齊。使毛(mao)(mao)細管(guan)(guan)(guan)(guan)(guan)4為垂直(zhi)狀(zhuang)態(tai)(tai)，視毛(mao)(mao)細管(guan)(guan)(guan)(guan)(guan)4下(xia)端(duan)(duan)(duan)端(duan)(duan)(duan)面(mian)(mian)(mian)(mian)(mian)(mian)與(yu)(yu)裝(zhuang)樣(yang)(yang)(yang)(yang)試(shi)(shi)(shi)(shi)(shi)管(guan)(guan)(guan)(guan)(guan)5內(nei)水(shui)(shui)(shui)(shui)液(ye)面(mian)(mian)(mian)(mian)(mian)(mian)的(de)相(xiang)對位置(zhi)，用滴(di)管(guan)(guan)(guan)(guan)(guan)穿過側(ce)(ce)(ce)管(guan)(guan)(guan)(guan)(guan)7往裝(zhuang)樣(yang)(yang)(yang)(yang)試(shi)(shi)(shi)(shi)(shi)管(guan)(guan)(guan)(guan)(guan)5內(nei)加(jia)入去(qu)(qu)離子(zi)水(shui)(shui)(shui)(shui)或者(zhe)吸(xi)(xi)取去(qu)(qu)離子(zi)水(shui)(shui)(shui)(shui)調節毛(mao)(mao)細管(guan)(guan)(guan)(guan)(guan)4下(xia)端(duan)(duan)(duan)端(duan)(duan)(duan)面(mian)(mian)(mian)(mian)(mian)(mian)恰好與(yu)(yu)水(shui)(shui)(shui)(shui)液(ye)面(mian)(mian)(mian)(mian)(mian)(mian)相(xiang)切。按圖(tu)5所(suo)示，通過軟管(guan)(guan)(guan)(guan)(guan)將裝(zhuang)樣(yang)(yang)(yang)(yang)試(shi)(shi)(shi)(shi)(shi)管(guan)(guan)(guan)(guan)(guan)5與(yu)(yu)滴(di)液(ye)漏斗1和微差(cha)(cha)壓差(cha)(cha)計3相(xiang)連。在(zai)滴(di)液(ye)漏斗1中加(jia)入水(shui)(shui)(shui)(shui)，塞(sai)(sai)緊(jin)活塞(sai)(sai)。用試(shi)(shi)(shi)(shi)(shi)管(guan)(guan)(guan)(guan)(guan)夾夾住裝(zhuang)樣(yang)(yang)(yang)(yang)試(shi)(shi)(shi)(shi)(shi)管(guan)(guan)(guan)(guan)(guan)主體部(bu)位，將裝(zhuang)樣(yang)(yang)(yang)(yang)試(shi)(shi)(shi)(shi)(shi)管(guan)(guan)(guan)(guan)(guan)5浸(jin)入恒(heng)溫(wen)(wen)浴槽(cao)6的(de)恒(heng)溫(wen)(wen)水(shui)(shui)(shui)(shui)中，裝(zhuang)有配制好的(de)待測(ce)溶液(ye)試(shi)(shi)(shi)(shi)(shi)樣(yang)(yang)(yang)(yang)的(de)容量(liang)瓶(ping)掛恒(heng)溫(wen)(wen)浴槽(cao)內(nei)預(yu)熱。調整裝(zhuang)樣(yang)(yang)(yang)(yang)試(shi)(shi)(shi)(shi)(shi)管(guan)(guan)(guan)(guan)(guan)5的(de)高度和左右、前(qian)后傾斜角，使得裝(zhuang)樣(yang)(yang)(yang)(yang)試(shi)(shi)(shi)(shi)(shi)管(guan)(guan)(guan)(guan)(guan)5內(nei)水(shui)(shui)(shui)(shui)液(ye)面(mian)(mian)(mian)(mian)(mian)(mian)位置(zhi)在(zai)恒(heng)溫(wen)(wen)浴槽(cao)6水(shui)(shui)(shui)(shui)液(ye)面(mian)(mian)(mian)(mian)(mian)(mian)以下(xia)，毛(mao)(mao)細管(guan)(guan)(guan)(guan)(guan)4為垂直(zhi)狀(zhuang)態(tai)(tai)。在(zai)側(ce)(ce)(ce)管(guan)(guan)(guan)(guan)(guan)口(kou)為敞開狀(zhuang)態(tai)(tai)下(xia)，進行微差(cha)(cha)壓差(cha)(cha)計3置(zhi)零(ling)操作，塞(sai)(sai)緊(jin)測(ce)管(guan)(guan)(guan)(guan)(guan)口(kou)活塞(sai)(sai)。

待恒溫(wen)浴槽6達(da)到(dao)試驗所需(xu)控(kong)制(zhi)溫(wen)度(du)并(bing)經另(ling)外(wai)10分(fen)鐘(zhong)以(yi)(yi)上恒溫(wen)后(hou)，可以(yi)(yi)認為裝(zhuang)樣試管(guan)5內的去離子水已經達(da)到(dao)試驗所需(xu)控(kong)制(zhi)溫(wen)度(du)。緩慢(man)開啟滴液(ye)(ye)漏(lou)斗1活塞(sai)，滴液(ye)(ye)漏(lou)斗1開始(shi)滴液(ye)(ye)，微(wei)差(cha)(cha)壓(ya)(ya)差(cha)(cha)計(ji)3示(shi)數(shu)(絕對(dui)值(zhi))逐漸增大(da)(da)，并(bing)在增大(da)(da)至某一(yi)(yi)值(zhi)時，毛(mao)細管(guan)4下端有氣泡逸出(chu)，同(tong)時微(wei)差(cha)(cha)壓(ya)(ya)差(cha)(cha)計(ji)3示(shi)數(shu)退回到(dao)某一(yi)(yi)值(zhi)。調節滴液(ye)(ye)漏(lou)斗活塞(sai)開啟程度(du)以(yi)(yi)控(kong)制(zhi)滴液(ye)(ye)速度(du)，使得微(wei)差(cha)(cha)壓(ya)(ya)差(cha)(cha)計(ji)3示(shi)數(shu)逐漸增大(da)(da)過(guo)程中(zhong)每次改變值(zhi)不(bu)超過(guo)10Pa。觀測毛(mao)細管(guan)4端面是否每次一(yi)(yi)個有規律的出(chu)泡，經一(yi)(yi)定時間連續滴液(ye)(ye)，微(wei)差(cha)(cha)壓(ya)(ya)差(cha)(cha)計(ji)3最(zui)大(da)(da)壓(ya)(ya)差(cha)(cha)示(shi)數(shu)具有很好的重現(xian)性(連續兩次最(zui)大(da)(da)壓(ya)(ya)差(cha)(cha)示(shi)數(shu)相差(cha)(cha)在1％以(yi)(yi)內)后(hou)，讀(du)取并(bing)記錄3個連續出(chu)現(xian)的最(zui)大(da)(da)壓(ya)(ya)差(cha)(cha)示(shi)數(shu)。

由于(yu)表面(mian)張(zhang)力(li)的(de)作(zuo)用，在(zai)彎曲(qu)(qu)液(ye)(ye)面(mian)內外(wai)存在(zai)一個壓力(li)差，稱為曲(qu)(qu)面(mian)附加壓力(li)。曲(qu)(qu)面(mian)附加壓力(li)的(de)方向指向曲(qu)(qu)率半(ban)(ban)徑中心，大小(xiao)與液(ye)(ye)體表面(mian)張(zhang)力(li)σ、彎曲(qu)(qu)液(ye)(ye)面(mian)曲(qu)(qu)率半(ban)(ban)徑R之(zhi)間的(de)關系(xi)稱為Laplace方程(cheng)：

Δp＝2σ/R

在(zai)最(zui)大氣泡(pao)法測定液體(ti)表面(mian)張力(li)(li)試驗過程中，伴隨滴液漏斗的(de)滴液，測量體(ti)系內(nei)部(bu)壓(ya)力(li)(li)逐漸(jian)降(jiang)低，相(xiang)(xiang)對于大氣壓(ya)力(li)(li)形(xing)成負壓(ya)。毛(mao)細(xi)管(guan)(guan)上(shang)端(duan)與大氣相(xiang)(xiang)通，因此在(zai)這一壓(ya)差的(de)驅(qu)動下(xia)，毛(mao)細(xi)管(guan)(guan)下(xia)端(duan)開始有(you)氣泡(pao)形(xing)成并逐漸(jian)長(chang)大。如果(guo)毛(mao)細(xi)管(guan)(guan)下(xia)端(duan)恰好與試樣液面(mian)相(xiang)(xiang)切，毛(mao)細(xi)管(guan)(guan)下(xia)端(duan)端(duan)面(mian)形(xing)成的(de)氣泡(pao)只需要承受彎(wan)曲(qu)(qu)液面(mian)曲(qu)(qu)面(mian)附(fu)加(jia)壓(ya)力(li)(li)的(de)作用(yong)。

毛(mao)(mao)細(xi)(xi)管下(xia)端(duan)端(duan)面剛開始形成(cheng)氣(qi)泡時(shi)，曲(qu)面幾乎是(shi)平的(de)，曲(qu)率(lv)半(ban)徑(jing)(jing)R很大(da)。而伴隨(sui)滴液漏斗不斷滴液，大(da)氣(qi)壓力(li)與測量(liang)(liang)體(ti)系內(nei)部的(de)壓差(cha)不斷變(bian)(bian)大(da)，氣(qi)泡逐(zhu)漸(jian)長大(da)，曲(qu)率(lv)半(ban)徑(jing)(jing)R逐(zhu)漸(jian)變(bian)(bian)小(xiao)，等到(dao)氣(qi)泡逐(zhu)漸(jian)長大(da)、曲(qu)率(lv)半(ban)徑(jing)(jing)R逐(zhu)漸(jian)變(bian)(bian)小(xiao)至恰好與毛(mao)(mao)細(xi)(xi)管半(ban)徑(jing)(jing)r相等時(shi)，氣(qi)泡隨(sui)之離(li)開毛(mao)(mao)細(xi)(xi)管端(duan)面進入測量(liang)(liang)體(ti)系內(nei)，內(nei)部壓力(li)略有回(hui)升，因此在氣(qi)泡剛好離(li)開毛(mao)(mao)細(xi)(xi)管下(xia)端(duan)端(duan)面時(shi)，微差(cha)壓差(cha)計(ji)示(shi)數(壓差(cha)的(de)絕對值)出(chu)現最大(da)值。

由基準試樣(一般為去離子水)測量得到的多次平行試驗最大壓差的平均值Δp_基準，并由文獻查得試驗溫度下基準試樣表面張力的理論值σ_基準，則有：

Δp_基準＝2σ_基準/r

其中(zhong)，r為試驗所用(yong)毛細管(guan)半徑。

同前述基準試樣(去離子水)測量過程但改用待測表面張力試樣，使用同一毛細管經多次平行試驗測量得到對應試樣的最大壓差的平均值Δp_試樣，則有：

Δp_試樣＝2σ_試樣/r

由此即可計算得到試驗溫度下待測試樣表面張力σ_試樣值：

σ_試樣＝σ_基準×Δp_試樣/Δp_基準。