1.1本標準規定了測定與玻璃瓶罐退火(huo)狀態(tai)有關的相應光程差的試驗方法。以下兩種方法可選擇(ze)使用。

方法A:用(yong)偏光儀與- -套標(biao)準片對(dui)比測量。

方法B:用偏光(guang)儀直(zhi)接測(ce)量(liang).

1.2 方法A適(shi)用(yong)于測(ce)(ce)定光(guang)程(cheng)差小于150 nm的試(shi)樣(yang),方法B適(shi)用(yong)于測(ce)(ce)定光(guang)程(cheng)差小于565 nm的試(shi)樣(yang)。

3偏光儀推薦：SG-03數顯偏光應力儀

3.1視域各處(chu)的偏 振度不(bu)小(xiao)于(yu)99%.

3.2視域至少比被測瓶(ping)罐(guan)大51mm.起偏鏡與(yu)分析鏡的距離應(ying)滿(man)足通過瓶(ping)口(kou)觀(guan)察瓶(ping)底的檢驗。

3.3附(fu)有光程差(cha)為(wei)565 nm的(de)靈敏色片,其在觀(guan)察視(shi)域(yu)中程差(cha)的(de)變化應(ying)小于(yu)5 nm,它的(de)慢軸與(yu)偏振面(mian)成45°,這樣(yang)(yang)在觀(guan)察視(shi)城里能(neng)產生紫紅(hong)色的(de)背景。樣(yang)(yang)品測定處的(de)亮(liang)度至少(shao)是300cd/m2。

注:色片程(cheng)差(cha)在(zai)510 nm和580 nm之間(jian)方能辨別顏色,zuilixiang是565 nm.

4標準片

使用一(yi)套不(bu)少于(yu)5片(pian)、且(qie)已知內(nei)應(ying)(ying)力的標(biao)準玻(bo)璃圓片(pian),此標(biao)準片(pian)應(ying)(ying)覆蓋玻(bo)璃瓶罐生產的退火范圍，圓片(pian)的直徑大(da)于(yu)76mm.小(xiao)于(yu)102mm,每片(pian)都具有規(gui)定的殘余應(ying)(ying)力,離開邊緣6.4mm處的光(guang)程(cheng)差的一(yi)致性應(ying)(ying)不(bu)小(xiao)于(yu)21. 8 nm,不(bu)大(da)于(yu)23. 8 nm.

5試驗步驟

5.1 圓柱形無色玻(bo)璃瓶罐底(di)部(bu)的檢驗

通過(guo)瓶(ping)口(kou)觀察瓶(ping)罐(guan)的(de)(de)底部,并(bing)旋轉瓶(ping)罐(guan),尋找瓶(ping)底應力最大(da)處(chu),將瓶(ping)底根部的(de)(de)最大(da)應力色(se)圖(tu)(tu)(tu)與(yu)-一個(ge)一個(ge)疊加起(qi)來的(de)(de)標準(zhun)片(pian)(pian)(pian)進行比(bi)較(標準(zhun)片(pian)(pian)(pian)與(yu)起(qi)偏鏡平行) ,觀察瓶(ping)底最大(da)應力是否小(xiao)于(yu)一片(pian)(pian)(pian)、大(da)于(yu)一片(pian)(pian)(pian)小(xiao)于(yu)二(er)片(pian)(pian)(pian)或大(da)于(yu)二(er)片(pian)(pian)(pian)小(xiao)于(yu)三(san)片(pian)(pian)(pian)等等,要獲得瓶(ping)底的(de)(de)應力色(se)圖(tu)(tu)(tu)與(yu)標準(zhun)參數(shu)wanquan一致的(de)(de)可 能性很(hen)小(xiao)。然后按照(zhao)下列規則(ze)記(ji)錄(lu)應力級(ji)數(shu):當瓶(ping)底的(de)(de)最大(da)應力色(se)圖(tu)(tu)(tu)大(da)于(yu)N片(pian)(pian)(pian)而小(xiao)于(yu)N+1片(pian)(pian)(pian)時,它的(de)(de)應力級(ji)數(shu)是N+1.

試樣的表(biao)觀應力(li)級數比實際觀察(cha)的應力(li)級數大(da)(見(jian)表(biao)1).

方法(fa)B:偏光儀直接測量(liang)法(fa)

7偏光儀

7.1視域(yu)各處的偏振度不(bu)小于(yu)99%.

7.2視域至少比被測瓶罐(guan)大(da)51mm.起偏鏡(jing)與分析(xi)鏡(jing)的距離應滿足(zu)通過瓶口觀察瓶底(di)的檢驗。

7.3 將(jiang)-塊具有光程差為141 nm士14 nm的(de)(de)四分之(zhi)(zhi)一波片(pian)插(cha)人樣(yang)品和檢偏(pian)(pian)鏡之(zhi)(zhi)間, 波片(pian)的(de)(de)慢軸隨起偏(pian)(pian)鏡的(de)(de)偏(pian)(pian)振平面(mian)而調整。偏(pian)(pian)振視域對樣(yang)品的(de)(de)亮度至少(shao)是300 cd/m*.

注:由于四分(fen)之- -波片偏(pian)離141 nm的(de)標稱值,或應力的(de)測定方向(xiang)偏(pian)離與偏(pian)振片成45°的(de)理想方位將(jiang)會影響光程差的(de)測定值。

四分之一(yi)波片偏(pian)離(li)14 nm和應(ying)力方向偏(pian)離(li)10* .產生的誤差(cha)不大于8 nm.

7.4檢偏鏡應裝成(cheng)能分別(bie)繞起偏鏡和(he)四分之-波(bo)片旋(xuan)轉,并能測定其旋(xuan)轉角。

8試驗步驟

8.1圓(yuan)柱(zhu)形無色玻璃瓶(ping)罐底部的檢(jian)驗

先(xian)旋轉(zhuan)(zhuan)檢(jian)(jian)偏(pian)(pian)(pian)(pian)鏡(jing),使(shi)起(qi)偏(pian)(pian)(pian)(pian)鏡(jing)的(de)(de)(de)(de)偏(pian)(pian)(pian)(pian)振面垂直(zhi)于(yu)檢(jian)(jian)偏(pian)(pian)(pian)(pian)鏡(jing)的(de)(de)(de)(de)偏(pian)(pian)(pian)(pian)振面,此時(shi)是(shi)零位,視(shi)域呈黑(hei)色(se),把瓶罐(guan)放(fang)人帶有靈敏(min)(min)色(se)片(pian)的(de)(de)(de)(de)觀測視(shi)域中(zhong)進(jin)行測定(ding)。旋轉(zhuan)(zhuan)瓶罐(guan),尋找瓶底內根部的(de)(de)(de)(de)最(zui)(zui)(zui)大光(guang)(guang)(guang)(guang)(guang)程差(cha)的(de)(de)(de)(de)顏色(se)。然后(hou)移去(qu)靈敏(min)(min)色(se)片(pian),通(tong)過(guo)瓶口觀察瓶底。在(zai)(zai)瓶底中(zhong)心(xin)將(jiang)出現(xian)(xian)(xian)暗(an)色(se)的(de)(de)(de)(de)消光(guang)(guang)(guang)(guang)(guang)十(shi)字(zi)(zi),十(shi)字(zi)(zi)之間(jian)具有明亮的(de)(de)(de)(de)區域,如(ru)(ru)果(guo)瓶罐(guan)的(de)(de)(de)(de)光(guang)(guang)(guang)(guang)(guang)程差(cha)較低,十(shi)字(zi)(zi)就(jiu)模糊不清。如(ru)(ru)果(guo)在(zai)(zai)觀察處(chu)(chu)推入(ru)靈敏(min)(min)色(se)片(pian)或將(jiang)瓶罐(guan)放(fang)在(zai)(zai)具有靈敏(min)(min)色(se)片(pian)的(de)(de)(de)(de)偏(pian)(pian)(pian)(pian)光(guang)(guang)(guang)(guang)(guang)儀里觀察,十(shi)字(zi)(zi)將(jiang)出現(xian)(xian)(xian)紫紅色(se)而不是(shi)黑(hei)色(se)。旋轉(zhuan)(zhuan)檢(jian)(jian)偏(pian)(pian)(pian)(pian)鏡(jing),使(shi)十(shi)字(zi)(zi)分離(li)成兩(liang)條暗(an)色(se)圓(yuan)弧(hu),且直(zhi)徑相等方向相反,朝(chao)著(zhu)瓶底根部的(de)(de)(de)(de)方向移動。隨(sui)著(zhu)兩(liang)條圓(yuan)弧(hu)向外(wai)移動,在(zai)(zai)圓(yuan)弧(hu)的(de)(de)(de)(de)凹側便出現(xian)(xian)(xian)藍(lan)灰色(se),在(zai)(zai)凸側便出現(xian)(xian)(xian)褐色(se),當測定(ding)瓶罐(guan)某-選定(ding)點的(de)(de)(de)(de)光(guang)(guang)(guang)(guang)(guang)程差(cha)時(shi),旋轉(zhuan)(zhuan)檢(jian)(jian)偏(pian)(pian)(pian)(pian)鏡(jing),直(zhi)到在(zai)(zai)選定(ding)點上(shang)藍(lan)灰色(se)剛好被褐色(se)取代(dai)為(wei)止。旋轉(zhuan)(zhuan)瓶罐(guan)的(de)(de)(de)(de)中(zhong)心(xin)軸(zhou),確定(ding)此點是(shi)否(fou)為(wei)最(zui)(zui)(zui)大光(guang)(guang)(guang)(guang)(guang)程差(cha),如(ru)(ru)果(guo)不是(shi),進(jin)--步旋轉(zhuan)(zhuan)檢(jian)(jian)偏(pian)(pian)(pian)(pian)鏡(jing),使(shi)最(zui)(zui)(zui)大光(guang)(guang)(guang)(guang)(guang)程差(cha)處(chu)(chu)的(de)(de)(de)(de)藍(lan)灰色(se)剛好被褐色(se)取代(dai)為(wei)止。檢(jian)(jian)偏(pian)(pian)(pian)(pian)鏡(jing)的(de)(de)(de)(de)旋轉(zhuan)(zhuan)角度與應力(li)級數(shu)的(de)(de)(de)(de)換算見表(biao)2.