Automatic Drying Unit (ADU)

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Product Brochure

The Automatic Drying Unit (ADU) provides a rapid drying method for compacted asphalt road cores that come from the jobsite wet and must be quickly analyzed for density. This equipment is ideal for same-day analysis of road cores to acquire data for correlation purposes, or to know if the asphalt placed that day meets specifications.

The ADU takes the place of drying the core samples in front of a fan or in a low temperature drying oven for several hours. The typical drying time is between 10 and 20 minutes, saving you hours of waiting. The core density can easily be determined within 30 minutes of arriving in the laboratory. The ADU can also dry loose aggregate or asphalt by using the bag provided with the unit.

Pushing the start button activates the vacuum pump, which draws the air out of the sample chamber. After the air is evacuated, the water is then drawn out of the sample. The attached heating mechanism keeps the sample close to room temperature.

User Friendly Interface and Simple One-Button Operation

The ADU is user friendly with a large, easy-to-read display and an audible alert that indicates when sample drying is finished. The menu driven operation provides clear, concise instructions from device setup to sample drying. To operate the ADU, just place the sample into the chamber, press the button, and wait for the beep.

The ADU Model 5151 complies with ASTM standard D7227 and AASHTO R79.


Cold Moisture Trap collects moisture to prevent damage to the pump.

Data Storage and Output automatically stores 20 data records and 4 calibration records

Regulates Chamber/Sample Temperature – prevents degrading of sample due to low or high drying temperature

Large Sample Chamber accommodates large samples up to 150 mm diameter and 8.5″ height

Aggregate and Loose Asphalt Drying – with provided sample holder, loose samples can be dried quickly

Service Alerts – automatically notifies when routine mainenance is required

Takes Up Less Lab Space – pump can be placed on a shelf or in a cabinet


Size 25″ W x 10″ D x 12″ H
(63.5 x 25.4 x 30.5 cm)
Shipping Dimensions (ADU) 30” W x 20” D x 20” H
(76.2 x 50.5 x 50.8 cm)
Shipping Dimensions (Pump) 22” W x 16” D x 16” D
(55.9 x 40.6 x 40.6 cm)
Weight 23 lbs (10.4 kg)
Shipping Weight ADU – 50 lbs (22.7 kg)
Pump – 35 lbs (15.9 kg)
Storage Temperature -55 to 85°C (-67 to 185°F)
Operating Temperature 2 to 38°C (55 to 101°F)
Measure Units Pressure reported in RVQ
Drying Time Moisture content dependant; 10-20 minutes average
Power 120 VAC
Calibration Internal pressure calibration performed daily
Serial Port 9-pin male RS232
Connector 8 data bit, 1 stop bit, no parity
Baud Rate 9600
Warranty One-year limited warranty


The Automatic Drying Unit gives you these proven advantages:

  • Dry cores and loose aggregate in less than 30 minutes
  • One-button operation
  • Self-driven and easy-to-follow software
  • Simple maintenance with annual reminders
  • All data is easily accessible
  • Forty years of Troxler experience and a twelve month warranty give you the confidence you need in your field testing equipment