StratoTest 4100

Road layer thickness measurement StratoTest 4100

A measuring device conceived for rough use on a construction site to gauge the thickness of all non-metallic layers in the context of construction work, like bituminous mixtures (asphalt), blast furnace slag, concrete etc.

The measuring process is non-destructive and TP D-StB 12 approved (Technical testing regulations applicable for calculating surface thickness in road construction) to gauge individual and total thickness of layers in road construction.

Use of the device in road constructions typically involves placing aluminium foil at the base of an asphalt layer yet to be applied. The foil gets packed in by the gravel mix and thus does not hamper the process of inter-layer bonding. Decades of experience have shown that the foils do not affect the stability of the asphalt layers.

Unlike the core drill method, this does not damage the construction layer.

The measuring reflectors can be located by a bar graph display on the measuring device or acoustically by the headphone included in the delivery.

There are three kinds of probes available for special applications in the construction sector:

  • N 100ST
    Up to 100 mm to measure the covering layer in road construction
  • N 400ST
    Measuring range between 0 and 400 mm to measure the base and covering layers in road construction
  • N 800ST
    Measuring range between 0 and 800 mm for landfill caps.


Non-destructive thickness measurement of non-magnetic layers in the field of construction, e.g.:

  • Asphalt, slag, gravel and concrete layers in road construction
  • Concrete layers in landfill construction work


  • Non-destructive measurement
  • TP D-StB 12 approved
  • Measuring range up to 800 mm
  • Direct display of thickness
  • Unlimited measurements repeatedly at the same spot
  • Easy location of the measuring reflectors

Scope of Delivery

  • StratoTest 4100 device
  • Measuring probe N 400ST
  • Foldable dolly for measuring
  • Calibration plate
  • Headphone
  • 9 V bloc battery, type 6LR61
  • Plastic carrying case
Property Value
Measuring principle
eddy current testing
Measurable layers
all non-metallic road layer materials
aluminium foils or sheets of different sizes
Measuring range
0 ... 40 cm N400ST standard probe
0 ... 10 cm N100ST optional probe
0 ... 80 cm N800ST optional probe
0.1 cm: 0 ... 30 cm
0.2 cm: 30 ... 35 cm
0.4 cm: 35 ... 40 cm
Tolerance of standard probe
Reflectors Measuring range / (cm) Tolerance

0.7 m x 0.3 m

1.0 m x 0.3 m

0 ... 30 ± (0.1 cm +2 % of reading)
30 ... 35 ± 2 % of reading
35 ... 40 ± 3 % of reading

0.6 m x 0.6 m

1.0 m x 1.0 m steel

0 ... -30 ± (0.1 cm +2 % of reading)
30 ... 35 ± 2 % of reading
35 ... 40 ± 2 % of reading
digital on LCD
Data memory

DIRECT mode: approx. 500 single readings and statistical values

SITE mode: approx. 6,000 single readings incl. statistics

5 site memories available with 300 stations each

4 measuring spots per station

5 layer material types per measuring spot

Power supply
1 x 9 V alkaline battery
~ 20 hours
Ambient temperature
gauge: 0 °C - 50 °C
probe: 0 °C - 70 °C

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Need technical advice?

You are working with a manufacturing process requiring special measuring methods and tools? It will be our pleasure to advise you on possible solutions!
Please feel free to contact us on:

Phone: +49 221 75204-0
Fax: +49 221 75204-67
Mail: info(at)

or using the -> contact form

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