According to IEC60112 clause 12.2,if the behaviour of the material is unknown,a screening test shall start with at least three specimens at a maximum starting voltage of 300V with a minimum of 50 drops.If the material withstands the initial test without tracking failure and without a persistent flame,always using three specimens,increase the test voltage by 100V steps until a tracking failure or a persistent flame occurs.Then reduce the test voltage by 50V,and Mwishowe ongeza au punguza voltage ya mtihani na 25V kutambua kiwango cha juu cha mtihani kwa uamuzi wa index ya ufuatiliaji wa kulinganisha. Ikiwa nyenzo zinashindwa kwenye voltage ya mtihani wa awali, punguza voltage ya mtihani na 100 V na ufuate utaratibu huo wa iterative kwa uamuzi wa index ya kulinganisha, kila wakati ukitumia vielelezo vitatu.
Utaratibu huu ni muhimu kwa sababu vifaa vingine vinaweza kuhimili voltages kubwa za mtihani, lakini inashindwa kwa voltages za mtihani wa chini.
Vifaa vya mtihani wa Ufuatiliaji wa ZLT, voltage ya mtihani inaweza kubadilishwa, ni vifaa vya upimaji wa hali ya juu.
