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 ) 已获实验所认可计划认可或正申请认可资格的实验所,须让其测试或测量设备定期接受校正,而校正工作须由有能力的校正机构执行,使测量能溯源至国际单位制。