Exposure of instrument has small or infrequence influence on measurement Class 2 class2 Exposure of instrument leads to high uncertainty or regular invalid measurements Class 4 class4 Exposure of instrument leads to increased uncertainty or occasional invalid measurements Class 3 class3 Exposure of instrument leads to invalid measurements Class 5 class5 Exposure of instrument Classification unknown unknown unknown 2 Exposure of instrument 2019-11-21T09:02:19.489Z None of the codes in the table are applicable in the context of this particular observation inapplicable inapplicable Exposure of instrument allows reference level measurements Class 1 class1