A review of literature indicated that the relationship between Log aT and T-Td is
linear when T-Td is between -15 and 35C and Td is between -15 and 5C (25). In this
study, the temperature of interest was between -10 and 20 C, and T-Td falls between -15
and 35C. Linear regression was performed for equation 4.1 within this temperature
range, which resulted in the following equation for the shift factor:
log a, = -0.175(T- Tef) (4.3)
This equation can be used regardless of whether T>Td or T