Troxler NTO 4730 - Calculating an ACF

Troxler NTO 6–7
6. CALIBRATION
CALCULATING AN ACF
1. Using the following equation, calculate and record the aggregate
correction factor for each correction sample:
ACF =%AC
0
– %AC
T
where: ACF = Aggregate correction factor
%AC
0
= Asphalt content of sample as determined by the
oven
%AC
T
= True asphalt content
2. Determine the average ACF value (ACF
AVG
) as follows:
f If the difference between the two ACF values is less than
0.15%, then average the two values.
f If the difference between the two ACF values is greater than
0.15%, then prepare two additional correction samples.
Discard the high and low ACF values, then average the two
remaining values.
3. Enter the ACF as described in the Create ACF sectio
n on page
6–10. The oven will automatically
adjust the asphalt content
measurements using the active ACF.