Material Testing Laboratory Equipment

RoadReader Nuclear Density Gauges (UTS-1050)

SKU: UTS-1050 Categories: ,

Compacted Road Base and Sub-base Soils

CodeUTS-1050 (Model 3440P)
StandardsASTM D 2950, C 1040, D 6938


  • The Troxler RoadReader nuclear moisture / density gauges are used by many contractors, engineers and highway departments for compaction control of soil, aggregate, concrete and full asphalt.
  • The ASTM standards numbers D 2922, D 3017, D 2950 and C 1040 are met or exceeded by these gauges. Two test models are available for density determination: Direct transmission and Backscatter.
  • The operator selects the mode depending on the material type and thickness of the layer being tested.
  • The model 3430 is available with keypad, display and operator’s manual in languages and is the simplest most economical gauge offered by Troxler.
  • The Model 3440 provides 30 special functions, storage of up to 1000 test records, an 18-month warranty and many more options that make it simple to operate and a necessity for all technicians.
Three Test Modes:
  • Backscatter is rapid and non-destructive.
  • The gamma source and detectors remain inside the gauge which rests on the surface of the test material.
  • Gamma rays enter the test material and those scattered through the material and reaching the detectors are counted.
  • Backscatter is primarily used to determine density on layers of asphalt and concrete approximately 4″ thick.
  • The gamma source is positioned at a specific depth within the test material by insertion into an access hole.
  • Gamma rays are transmitted through the test material to detectors located within the gauge.
  • The average density between the gamma source and the detectors is then determined.
  • Errors resulting from surface roughness and chemical composition of the test material are greatly reduced and gauge accuracy is improved.
  • Direct transmission is used for testing lifts of soil, aggregate, asphalts and concrete up to 12″ depth.
  • The moisture measurement is non-destructive with the neutron source and detector located inside the gauge just above the surface of the test material.
  • Fast neutrons enter the test material and are slowed after colliding with the hydrogen atoms present.
  • The helium 3 detector in the gauge counts the number of thermalized (slowed) neutrons which relates directly to the amount of moisture in the sample.

Both Models Offer:

  • Direct readout of wet density, dry density, moisture, %moisture, %voids and %compaction.
  • Lightweight
  • Powered by rechargeable nicad batteries or backup alkaline batteries
  • Prompts user through steps of operation
  • Software allows for moisture, density and trench offsets
3440 Features:
  • Data storage- stores up to 1000 complete test records which can be downloaded to a printer or computer.
  • Extended storage-gauge allows notes to be stored with test record.
  • Automatic indexing-eliminates a major source of operator error by automatically sensing depth of measurement.
  • 30 special functions provided-self test and service programs, selected precision and field calibration for special materials.
  • Calculator mode with storage.
  • Nomograph method for measurement of asphalt overlays.
Measurement (U.S. Customary Units)
Direct Transmission Density (6″) Pcf=lb/ft315 sec.1 min.4 min.
Precision at 120 pcf±0.42 pcf±0.21 pcf±0.11 pcf
Composition error at 120 pcf±1.25 pcf±1.25 pcf±1.25 pcf
Surface error (0.05″, 100% Void)-1.1 pcf-1.1 pcf-1.1 pcf
Backscatter (98%) (4″)15 sec.1 min.4 min.
Precision at 120 pcf±1.00 pcf±0.50 pcf±0.25 pcf
Composition error at 120 pcf±2.50 pcf±2.50 pcf±2.50 pcf
Surface error (0.05″, 100% Void)-4.7 pcf-4.7 pcf-4.7 pcf
Moisture at 15 pcf15 sec.1 min.4 min.
Precision at 15 pcf±0.64 pcf±0.32 pcf±0.16 pcf
Surface error (0.05″, 100% Void) Depth of measurement

@ 15 pcf (8.45″)


-1.12 pcf


-1.12 pcf


-1.12 pcf



Measurement (S.I.  Units)
Direct Transmission Density-150mm15 sec.1 min.4 min.
Precision at 2000 kg/m3±6.8 kg/m3±3.4 kg/m3±1.7 kg/m3
Composition error at 2000 kg/m3±20.0 kg/m3±20.0 kg/m3±20.0 kg/m3
Surface error (1.25mm, 100% Void)-17.0 kg/m3-17.0 kg/m3-17.0 kg/m3
Backscatter (98%) (100mm)15 sec.1 min.4 min.
Precision at 2000 kg/m3±16.0 kg/m3±8.0 kg/m3±4.0 kg/m3
Composition error at 2000 kg/m3±40.0 kg/m3±40.0 kg/m3±40.0 kg/m3
Surface error (1.25mm, 100% Void)-75.0 kg/m3-75.0 kg/m3-75.0 kg/m3
Moisture15 sec.1 min.4 min.
Precision at 250 kg/m3±10.3 kg/m3±5.1 kg/m3±2.6 kg/m3
Surface error (1.25mm, 100% Void)

Meas. Depth @ 250 kg/m3 – 212.5mm

-18.0 kg/m3-18.0 kg/m3-18.0 kg/m3


Gamma Source8 mCi ±10% Cs-137
Neutron Source0.060 mCi ±10% Cf-252 or

40 mCi ±10% Am-241: Be

Source HousingStainless Steel Encapsulation
ShieldingTungsten, lead and cadmium
Surface Dose Rates19 mrem/hr max., neutron and gamma
Source Rod MaterialStainless Steel
Shipping CaseDOT 7A, Type A Yellow label II, Tl=0.3
CaseHigh Impact Plastic: 75L x 35W x 42 T in.
Vibration Test0.1 in. (2.5 mm) @ 12.5 hz
Drop Test300 mm on 25 mm diameter steel ball
Operating Temp:Ambient: 14 to 158°F (-10 to 70°C) Surface: 350°F (175°C)
Storage Temp.-70 to 185°F (-55 to 85°C)
Weight29 lbs. (13.2 kg)
Shipping Weight90 lbs. (40.8 kgs) w/case
Available Models8″ or 12″ index rod with 1″ or 2″ increments

(200- or 300-mm index rod with 25- or 50-mm increments)

Time Accuracy and Stability0.005%, 0.0002% / °C
Power Supply Stability0.01% / °C
Stored Power30-watt hours
Battery Recharge Time14-16 hours (automatic cutoff)
Charger110/220 V ac, 50-60 Hz or 12-14 V dc
Readout2 x 16 alpha-numeric liquid crystal display
·         Gauge returns to Gauge Ready (power saving mode) after two minutes of inactivity, except in standard, stat test, drift test, and in nomograph programs when a 30-minute delay is provided.

·         After 5 hours of inactivity, gauge performs complete power shut-down.

·         Battery packs are fully protected against overcharge and over discharge.

·         Emergency Use – Capable of operation with D size alkaline batteries.

Due to the continuous development of our products, the goods supplied may vary in detail to that illustrated on this Website.


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