Troxler NTO
6–3
6. CALI
BRA
TION
EQUIPMENT NEEDED
The following equipment is required to determine an ACF to adjust
the %AC measurements:
♦
Troxler NTO Asphalt Content Ignition Oven
♦
Safety equipment - including but not limited to heat-resistant
gloves and face shield
♦
External scale precise to
±
0.1 g
♦
Drying oven that can maintain 105
°
C (221
°
F) per ASTM
D 6307,
Standard Test Method for Asphalt Content of Hot-Mix
Asphalt by Ignition Method
♦
Stainless steel mixing bowl and assorted spoons and spatulas
♦
Sample basket assembly (provided)
♦
Aggregate correction factor form (see sample in Figure 6–1)
PREPARING CORRECTION SAMPLES
See the safety warnings in Chapter 2. Refer to Figure 6–1 on the
following page for a sample form for recording and calculating data.
To prepare correction samples, follow the steps below:
1.
Ensure that the oven is properly set up for ignition (see Chapter
4) with an ACF of 0.0%. See page 6–8 for instructions on
changing the ACF, if necessary.
2.
Begin testing using the
Default
burn profile (see page 5–9), then
select one of the optional profiles, if necessary.
3.
To ensure the accuracy of the ACF calculations, allow the oven
temperature to reach an equilibrium point. Allow at least 120 –
150 minutes for a 120 V ac (Model 4730) unit or 60 – 90
minutes for a 240 V ac (Model 4731) unit.
NOTE
To ensure consistent, repeatable results, Troxler
recommends allowing the oven chamber to reach 400
°
C
(750
°
F) for a 120 V ac (Model 4730) unit or 375
°
C
(707
°
F) for a 240 V ac (Model 4731) unit before burning
a sample.
Summary of Contents for NTO 4730
Page 10: ...x LIST OF TABLES Table Title Page 4 1 Oven Keys 4 3 5 1 Recommended Minimum Burn Times 5 6...
Page 30: ...2 10 NOTES...
Page 90: ...5 36 NOTES...
Page 110: ...6 20 NOTES...
Page 136: ...Appendix A 16 NOTES...
Page 148: ...Appendix C 6 NOTES...
Page 156: ...Index 8 NOTES...