一、ph計是什么意思
ph計是測量pH值的儀器。
ph計是專(zhuan)為使(shi)(shi)(shi)用(yong)離子選擇電(dian)(dian)(dian)極(ji)而(er)(er)設計(ji)(ji)的(de)(de)(de)一(yi)種(zhong)精密(mi)的(de)(de)(de)電(dian)(dian)(dian)子毫伏計(ji)(ji)。由于(yu)pH指示電(dian)(dian)(dian)極(ji)的(de)(de)(de)電(dian)(dian)(dian)位隨溶液(ye)pH值(zhi)(zhi)(zhi)(zhi)的(de)(de)(de)變(bian)化而(er)(er)變(bian)化,所以(yi)當(dang)pH指示電(dian)(dian)(dian)極(ji)(如(ru)pH玻璃電(dian)(dian)(dian)極(ji))和參比電(dian)(dian)(dian)極(ji)(如(ru)飽和甘汞電(dian)(dian)(dian)極(ji))浸在(zai)溶液(ye)中(zhong)構成測(ce)量(liang)電(dian)(dian)(dian)池(chi)(chi)時,所產(chan)生的(de)(de)(de)電(dian)(dian)(dian)動(dong)(dong)勢與(yu)溶液(ye)的(de)(de)(de)pH值(zhi)(zhi)(zhi)(zhi)有關(guan)。pH計(ji)(ji)將電(dian)(dian)(dian)動(dong)(dong)勢輸出轉(zhuan)換(huan)成pH讀(du)數,每一(yi)pH間隔相(xiang)當(dang)于(yu)2.303RT/F伏,此值(zhi)(zhi)(zhi)(zhi)隨測(ce)量(liang)電(dian)(dian)(dian)池(chi)(chi)中(zhong)溶液(ye)的(de)(de)(de)溫(wen)度不同而(er)(er)變(bian)動(dong)(dong),所以(yi)pH計(ji)(ji)上都(dou)裝(zhuang)有溫(wen)度補償旋鈕,調節它(ta)可(ke)使(shi)(shi)(shi)每一(yi)pH間隔的(de)(de)(de)電(dian)(dian)(dian)動(dong)(dong)勢改變(bian)值(zhi)(zhi)(zhi)(zhi)正好(hao)相(xiang)當(dang)于(yu)測(ce)量(liang)溫(wen)度應有的(de)(de)(de)變(bian)動(dong)(dong)值(zhi)(zhi)(zhi)(zhi)。pH計(ji)(ji)上還裝(zhuang)有定位調節器(qi),其作用(yong)是在(zai)電(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)動(dong)(dong)勢上加一(yi)個適當(dang)電(dian)(dian)(dian)壓,使(shi)(shi)(shi)pH計(ji)(ji)讀(du)數與(yu)標(biao)準(zhun)pH值(zhi)(zhi)(zhi)(zhi)一(yi)致(zhi)。這樣,溶液(ye)的(de)(de)(de)pH值(zhi)(zhi)(zhi)(zhi)直接在(zai)儀表(biao)上顯示出來。pH計(ji)(ji)的(de)(de)(de)一(yi)般測(ce)量(liang)范圍是pH0~14,并備有±mV擋(dang)以(yi)擴展使(shi)(shi)(shi)用(yong)范圍。
二、ph計有哪些種類
現在(zai)市面上流(liu)通的酸度(du)計(ji)(ji)主要(yao)為實(shi)驗室酸度(du)計(ji)(ji)、工業pH計(ji)(ji)、便攜式pH計(ji)(ji)和筆式酸度(du)計(ji)(ji)四大類。
1、實驗室pH計,一(yi)般(ban)(ban)為(wei)(wei)臺式儀器,具有(you)精度高、重復性(xing)好、響(xiang)應(ying)快、功(gong)能(neng)全、操作(zuo)簡單(dan)等(deng)特點。如果為(wei)(wei)智能(neng)化儀器,一(yi)般(ban)(ban)還具有(you)打(da)印輸出、數據處理(li)等(deng)功(gong)能(neng)。
2、工(gong)業pH計,主(zhu)要用于工(gong)業流程(cheng)的連續測(ce)量(liang),要求(qiu)電極的長(chang)期穩(wen)定性好,儀表不僅要有(you)測(ce)量(liang)顯(xian)示功(gong)能,還(huan)要有(you)報警和(he)控(kong)制(zhi)功(gong)能,以及方(fang)便(bian)安裝、清洗、抗干擾性能好等(deng)優勢。
3、便攜式(shi)pH計(ji),主要用于現(xian)場測試和(he)野外測量,要求(qiu)附件配置齊(qi)全(quan)、方便攜帶,一般電(dian)源內置,方便移(yi)動測量。儀器的(de)(de)顯(xian)示要滿足戶外不(bu)同(tong)光(guang)線條(tiao)件下(xia)的(de)(de)讀數(shu)。
4、筆式酸度計,筆式酸度計(ji)是(shi)方便用(yong)戶攜帶(dai),在現場或野(ye)外操(cao)作而設計(ji)的。可同(tong)時(shi)顯示PH值和溫(wen)度值,該儀器適用(yong)于自來水(shui)水(shui)源的監(jian)測(ce)(ce),水(shui)族、水(shui)產(chan)、養殖、環(huan)保、印(yin)染、電鍍、飲(yin)料行業及科研單位等對水(shui)質、PH值的測(ce)(ce)定。