Recognizing the need for an improved method of measuring the density of thin layer asphalt overlays, Troxler developed the first true thin layer density gauge, the 4640-B Surface Thin Layer Density Gauge.

Designed to measure the density of thin asphalt and concrete layers from 2.5 to 10 cm (1 - 4 inches), the Troxler Model 4640-B Thin Layer Density Gauge accurately measures the overlay density without influence from underlying material. No nomographs or manual corrections are required in order to compute the true density of the overlay. With onsite results available in as little as one minute, the Model 4640-B can provide the user with test results when they are needed, not hours after compaction has been completed.

Special Functions

• Automatic standard count comparison and storage
• Data storage of 750 records for later viewing, printing, and/or downloading
• Determination of the count time for selected precision
• Field offsets of density and a special calibration function
• Calculator mode
• Diagnostics and self-test modes
• Simple data transfer to a portable device using the free Troxler App

The Troxler Model 4640-B Thin Layer Density Gauge complies with ASTM D2950 and AASHTO T 355.