首先確定比對(dui)和驗(yan)(yan)證(zheng)試(shi)驗(yan)(yan)類(lei)型,比對(dui)和驗(yan)(yan)證(zheng)試(shi)驗(yan)(yan)的類(lei)型要(yao)根據產品項(xiang)目的實際情況、儀器設備(bei)情況及比對(dui)和驗(yan)(yan)證(zheng)試(shi)驗(yan)(yan)的目的來確定。進行比對(dui)和試(shi)驗(yan)(yan)的產品應(ying)是經常檢(jian)驗(yan)(yan)、比較(jiao)容易(yi)獲得(de)的樣品。比對(dui)和驗(yan)(yan)證(zheng)試(shi)驗(yan)(yan)的項(xiang)目應(ying)是比較(jiao)穩定、定量的項(xiang)目。