Rolling Thin Film Oven
Compliant with AASHTO, ASTM, EN and CTM testing standards
Super accurate P.I.D. controller
Double walled temperature cabinet
Invented, designed and manufactured in California
The industry standard since testing began

The Superpave PG binder specification looked for tests which would closely simulate field performance. Hotmix asphalt binder experiences significant aging during the manufacturing and laying process. Investigating this phenomenon within a laboratory environment, with a repeatable and simple test is very useful within the design process.

The Rolling Thin Film Oven (RTFO) test is used to measure the effect of heat and air on a moving film of semi-solid asphalt binder. The results of this treatment are determined from measurements of the binder properties before and after the test.

Repeatability of the test is directly related to the accuracy with which the oven temperature can be maintained and the reproducibility of the thermal rise time of the system. The invention of RTFO by James Cox & Sons led to the present day AASHTO, ASTM and EN standards for Rolling Thin Film Oven test (RTFOT).

  • Invented, designed and manufactured in California
  • Super accurate P.I.D. controller
  • Low thermal mass RTD
  • Over temperature safety cut-out
  • Double walled temperature cabinet
  • Unique temperature control suppression
  • Made in California

ConstructionDouble-walled construction
16-gauge welded steel exterior
18-gauge corrosion resistant stainless steel interior
Insulation mm (inch)89 mm (3.5) of high density fiberglass insulation
ControllerProgrammable microprocessor UL listed
Temperature DisplayMeasured Temperature – 4 digit red LEDs
Temperature Set Point – 4 digit green LEDs
Thermal ProtectionPrevents oven from overheating in the event of control failure
Temperature RangeAmbient to 200°C (390°F)
VentsDouble exhaust vents for dissipation of expended volatile from specimen
Air Flow AdjustmentNeedle valve (long taper)
Air Pressure GaugeRange 0 – 100 psi
Heat Exchanger5/16 inch diamete copper tube
Electrical SupplyCS0325-1060: 1 Ph 208-230 V 60 Hz
CS0325-1061: 1 Ph 208-230 V 60 Hz
CS0325-1062: 1 Ph 208-230 V 60 Hz
(With Digital Flowmeter)
CS0325-1063: 1 Ph 208-230 V 60 Hz
(With Digital Flowmeter – International)
CS0325-1050: 1 Ph 208-230 V 50 Hz
CS-0325-1051: 1 Ph 208-230 V 50 Hz
(With Digital Flowmeter – International)
Dimensions (WxDxH) mm (inch)1016 x 660 x 915 (40 x 26 x 36)
Estimated Weight Kg (lbs)173 (380)

Years of Experience Supplying Research Equipment

The Rolling thin film oven was first developed by James Cox. James (Jim) Cox initially worked as a design engineer developing products to test asphalt for highway construction. He worked with engineers from Shell Oil and they modified a Blue M Convection oven, that is where inner liner design that is still in use came from. James left to set up his own business, originally working from his garage in Sacramento. Later Jim set up “James Cox & Sons”. The invention of Rolling Thin Film Oven (RTFO) by Cox & Sons led to the present day AASHTO, ASTM and EN standards for Rolling Thin Film Oven test.
Invention of RTFO


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