Laboratories accredited or seeking accreditation under hoklas are required to have their testing and measuring equipment regularly calibrated by a competent calibration organisation to obtain measurement traceability to the international system of units ( si ) 已獲實(shí)驗(yàn)所認(rèn)可計(jì)劃認(rèn)可或正申請認(rèn)可資格的實(shí)驗(yàn)所,須讓其測試或測量設(shè)備定期接受校正,而校正工作須由有能力的校正機(jī)構(gòu)執(zhí)行,使測量能溯源至國際單位制。