一、ph計是什么意思
ph計是測量pH值的儀(yi)器(qi)。
ph計是專(zhuan)為使(shi)(shi)用(yong)離子(zi)選擇(ze)電(dian)(dian)(dian)(dian)極(ji)(ji)(ji)而設計(ji)的(de)(de)(de)一(yi)種精密的(de)(de)(de)電(dian)(dian)(dian)(dian)子(zi)毫伏(fu)計(ji)。由于(yu)pH指(zhi)示(shi)電(dian)(dian)(dian)(dian)極(ji)(ji)(ji)的(de)(de)(de)電(dian)(dian)(dian)(dian)位隨溶液pH值(zhi)的(de)(de)(de)變化而變化,所(suo)以當(dang)pH指(zhi)示(shi)電(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(如pH玻璃電(dian)(dian)(dian)(dian)極(ji)(ji)(ji))和參比電(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(如飽(bao)和甘汞電(dian)(dian)(dian)(dian)極(ji)(ji)(ji))浸在溶液中構成測量電(dian)(dian)(dian)(dian)池(chi)時,所(suo)產生(sheng)的(de)(de)(de)電(dian)(dian)(dian)(dian)動(dong)(dong)勢(shi)與溶液的(de)(de)(de)pH值(zhi)有(you)(you)關。pH計(ji)將電(dian)(dian)(dian)(dian)動(dong)(dong)勢(shi)輸出(chu)轉換成pH讀數,每(mei)一(yi)pH間隔相(xiang)當(dang)于(yu)2.303RT/F伏(fu),此值(zhi)隨測量電(dian)(dian)(dian)(dian)池(chi)中溶液的(de)(de)(de)溫度不同(tong)而變動(dong)(dong),所(suo)以pH計(ji)上都裝有(you)(you)溫度補償(chang)旋鈕,調節它(ta)可(ke)使(shi)(shi)每(mei)一(yi)pH間隔的(de)(de)(de)電(dian)(dian)(dian)(dian)動(dong)(dong)勢(shi)改變值(zhi)正好相(xiang)當(dang)于(yu)測量溫度應有(you)(you)的(de)(de)(de)變動(dong)(dong)值(zhi)。pH計(ji)上還(huan)裝有(you)(you)定位調節器,其(qi)作用(yong)是在電(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)動(dong)(dong)勢(shi)上加(jia)一(yi)個適當(dang)電(dian)(dian)(dian)(dian)壓,使(shi)(shi)pH計(ji)讀數與標準pH值(zhi)一(yi)致。這(zhe)樣,溶液的(de)(de)(de)pH值(zhi)直接在儀表上顯示(shi)出(chu)來。pH計(ji)的(de)(de)(de)一(yi)般測量范圍(wei)是pH0~14,并備有(you)(you)±mV擋以擴展使(shi)(shi)用(yong)范圍(wei)。
二、ph計有哪些種類
現在市面上流通的酸度計(ji)(ji)主要為實驗室酸度計(ji)(ji)、工業pH計(ji)(ji)、便攜式pH計(ji)(ji)和筆式酸度計(ji)(ji)四大類。
1、實驗室(shi)pH計(ji),一般(ban)為臺式儀器,具有精度高、重復性(xing)好、響應快、功(gong)能(neng)全、操作簡單等特點。如果為智能(neng)化儀器,一般(ban)還具有打印輸(shu)出(chu)、數(shu)據處理等功(gong)能(neng)。
2、工業(ye)pH計(ji),主要用于(yu)工業(ye)流程的連續測量,要求電(dian)極的長(chang)期(qi)穩定性(xing)(xing)好,儀表不僅要有測量顯示功能,還(huan)要有報警(jing)和(he)控制功能,以及方便安裝(zhuang)、清洗、抗干擾性(xing)(xing)能好等(deng)優勢。
3、便(bian)(bian)攜(xie)式(shi)pH計,主要用于現場(chang)測試和野(ye)外測量,要求附件配(pei)置齊全、方(fang)便(bian)(bian)攜(xie)帶(dai),一般電源內置,方(fang)便(bian)(bian)移動測量。儀器的顯示要滿足戶外不同光(guang)線條(tiao)件下的讀數。
4、筆式酸度計,筆(bi)式酸度計(ji)是方便用(yong)戶(hu)攜帶,在現場或野(ye)外操(cao)作(zuo)而設計(ji)的。可同(tong)時顯示PH值(zhi)和(he)溫度值(zhi),該儀(yi)器適(shi)用(yong)于(yu)自來水(shui)水(shui)源(yuan)的監測(ce),水(shui)族、水(shui)產、養殖、環(huan)保(bao)、印(yin)染、電鍍、飲料行業及(ji)科研單(dan)位等對水(shui)質、PH值(zhi)的測(ce)定。