RoadReader Model 3430/3440 Moisture-Density Gauge

About Troxler Products

Troxler Electronic Laboratories, Inc. is a world leader in the manufacturing of testing/quality control measurement equipment for the construction industry. We are recognized worldwide as the industry standard for Nuclear Moisture/Density Gauges. In addition to nuclear gauges, Troxler is also a leader in the production of Gyratory Compactors and Asphalt Ignition Ovens. Troxler continues to set new product standards of quality and precision in the construction industry. For a complete list of Troxler equipment, please review this Products section.

The Troxler nuclear moisture density gauges are used by many contractors, engineers, and highway departments for compaction control of soil aggregate, concrete, and full depth asphalt. The gauges meet or exceed the ASTM standards D6938, D2950, and C1040. The operator selects the density measurement mode, backscatter, or direct transmission based on the material type and the thickness of the layer being measured.

These updated gauges offer new standard features and many optional new features. The owner can customize the gauge to meet their testing needs.

The Model 3430 is the simplest and most economical gauge offered by Troxler. This gauge offers many features, including:

  • Improved operation and reliability with updated electronics
  • Fast recharge with NiMH batteries
  • Easier to read in all lighting situations with an enlarged backlit display screen - 8mm characters

Optional features for the Model 3430 include:

  • Remote start keypad near the handle
  • Alkaline batteries for backup use
  • External beeper
  • Software, keypad, and manual in Spanish and French
  • Data storage
  • USB port


The Model 3440 is for users who want user-friendly features. Along with the standard features provided in the Model 3430, the Model 3440 provides additional features including:

  • Automatic depth function
  • USB port for data transfer
  • Data storage (1000 readings)
  • Alkaline battery backup

Optional features offered for the Model 3440 include:

  • GPS location
  • Remote start keypad near the handle
  • Backlit keypad
  • External beeper
  • Software, keypad, and manual in Spanish and French

Both models offer:

  • Density measurement capability in backscatter or direct transmission mode
  • Moisture measurement in backscatter mode to allow quick, non-destructive testing of soil, asphalt and concrete materials
  • Direct readout of test results (wet density, dry density, moisture, % moisture, % voids, and % compaction)
  • Multiple count time options (15 seconds, 1 minute, 4 minutes)
  • User-friendly menus and keypads
  • Options of 12”/2”, 12”/1” and 8”/2” depth measurement capability
  • 18 month warranty

For information on the legacy 3430 and 3440 Gauges, refer to the Documents TAB.


Measurement Specifications

Direct Transmission (150 mm)


.25 min

1 min

4 min

Precision kg/m3 (pcf)

±6.8 (±0.42)

±3.4 (±0.21)

±1.7 (±0.11)

Composition error (kg/m3)




Surface error (kg/m3)
(100% Void)




Backscatter (98%, 100 mm)

Precision (kg/m3)




Composition error (kg/m3)




Surface error (kg/m3)
(100% Void)




Surface error (kg/m3)
(100% Void)




Moisture at 240 kg/m3

Precision (kg/m3)




Surface error (kg/m3)
(1.25 mm, 100% void, kg/m3)




Mechanical Specifications

Gauge Size (including handles)

12” - 23.5”x9”x14.5”
(59cm x 22.9cm x 36cm)
8” - 19.5” height (49.5cm)

Shipping Case Size

29.4” x 13.9” x 16.5”

(75cm x 35cm x 42cm)


Shipping Weight

83lbs (37.6kg)


31lbs (14.1kg)

Operating Temperature

Ambient: 32 to 158oF (0 to 70oC)


350°F (175°C) for 15 minutes

Storage Temperature

-70 to 185°F (-55 to 85°C)

Radiological Specifications

Gamma Source

0.30 GBq (8mCi) ± 10% Cs-137

Neutron Source

1.48 GBq (40mCi) ± 10% Am-241:Be

Source Housing

Stainless steel, encapsulated

Surface Dose Rate

(5cm) 19 mrem/hr maximum, neutron and gamma

Shipping Case

DOT 7A, Type A, Yellow II label, TI=0.3

Electrical Specifications

Main Power Source

5C NiMH (Rechargeable Pack)

Backup Power Source

5 AA Alkaline Batteries – 3440
Optional - 3430

Stored Power

4 Ampere hours

Battery Recharge Time

3 hours maximum, auto cutoff

Charge Source

110/220 VAC, 50 or 60 Hz or 12-14 VDC

Current Consumption Average

35 mA

Time Before Auto Shutdown

5 hours of inactivity


4 x 20 Alphanumeric


30 key sealed membrane – 3440
10 key sealed membrane – 3430



Model 3430 Options:

  • Remote start keypad near the handle
  • External Beeper
  • Data Storage (100 readings)
  • USB port for data transfer
  • Alkaline battery backup feature
  • Spanish and French language options

Model 3440 Options:

  • Remote start keypad on the handle
  • External beeper
  • Backlit keypad for low light conditions
  • GPS locations for measurements
  • Spanish and French language options


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