石(shi)(shi)(shi)膏(gao)線(xian)(xian)(xian)簡單(dan)的(de)(de)鑒別(bie)方(fang)法(fa)是(shi)(shi)敲擊法(fa)。所(suo)謂敲擊法(fa)是(shi)(shi)用(yong)(yong)手(shou)指彈(dan)擊石(shi)(shi)(shi)膏(gao)線(xian)(xian)(xian)的(de)(de)表(biao)(biao)面,如(ru)果(guo)是(shi)(shi)優(you)(you)質(zhi)的(de)(de)石(shi)(shi)(shi)膏(gao)線(xian)(xian)(xian),此(ci)時會發(fa)出清脆的(de)(de)鋼響聲,而如(ru)果(guo)是(shi)(shi)劣(lie)質(zhi)的(de)(de)石(shi)(shi)(shi)膏(gao)線(xian)(xian)(xian)不會發(fa)出這種聲音。我們可(ke)以(yi)通過觀察石(shi)(shi)(shi)膏(gao)線(xian)(xian)(xian)的(de)(de)表(biao)(biao)面進行鑒別(bie)。一般優(you)(you)質(zhi)的(de)(de)石(shi)(shi)(shi)膏(gao)線(xian)(xian)(xian)表(biao)(biao)面不僅潔白(bai)細膩、亮(liang)度高、而且(qie)摸起來還非常干(gan)燥結(jie)實,背面也十分(fen)平整;而偽劣(lie)的(de)(de)石(shi)(shi)(shi)膏(gao)線(xian)(xian)(xian)大多是(shi)(shi)用(yong)(yong)石(shi)(shi)(shi)膏(gao)粉(fen)加增(zeng)白(bai)劑制成的(de)(de),它的(de)(de)表(biao)(biao)面顏色非常昏暗,甚至呈現發(fa)青的(de)(de)顏色。
看(kan)石(shi)(shi)膏線(xian)(xian)的斷(duan)面(mian),石(shi)(shi)膏線(xian)(xian)的內(nei)部鋪設(she)了很多層(ceng)的纖(xian)維(wei)網,如此不僅保證了石(shi)(shi)膏線(xian)(xian)條能附著在纖(xian)維(wei)網上(shang),也增(zeng)加了石(shi)(shi)膏線(xian)(xian)的強(qiang)度(du),因此優質的石(shi)(shi)膏線(xian)(xian)的內(nei)部一定是鋪設(she)了數層(ceng)纖(xian)維(wei)網的。
而反(fan)觀劣質(zhi)的(de)石(shi)(shi)(shi)膏(gao)線(xian)內(nei)部(bu)鋪設的(de)纖(xian)維(wei)網不是沒有(you)鋪滿是層(ceng)數太少,甚至是用(yong)其它的(de)材質(zhi)代替,這樣的(de)石(shi)(shi)(shi)膏(gao)線(xian)的(de)附著力會大大減弱,質(zhi)量也非常差。因此,我(wo)們建議消費者在購買石(shi)(shi)(shi)膏(gao)線(xian)條時可以把石(shi)(shi)(shi)膏(gao)線(xian)切開一(yi)小部(bu)分,觀察其內(nei)部(bu)結構,檢查內(nei)部(bu)的(de)纖(xian)維(wei)網的(de)網質(zhi)和層(ceng)數,這也是一(yi)個十分有(you)用(yong)的(de)方法(fa)。