Grading Standard

Surface Temperature Class

μ + SD ≤ T_i

High temperature region (HT)

μ + 0.5SD ≤ T_i < μ + SD

Secondary high temperature region (SHT)

μ − 0.5SD ≤ T_i < μ + 0.5SD

Middle temperature region (MT)

μ − SD ≤ T_i < μ − 0.5SD

Secondary low temperature region (SLT)

T_i < μ − SD

Low temperature region (LT)