Automatic constant energy penetrometer

The GTR790 mk3 is a tracked constant energy dynamic penetrometer. The successor to the GTR790MK1, it is equipped with electric starting and entirely hydraulic mast adjustment.

Its simple design makes it a very reliable machine which is easy to maintain. The adjustable dynamic probing system enables testing in DPL, DPM, DPH DPSH-A configuration, in accordance with the NF P 22476-2 standard. This device is also frequently used in SPT configuration with a dropping mass drop height of 75cm.

This penetrometer can be equipped with a data acquisition system and data processing software which allows test parameters to be recorded. Due to its data acquisition system, this assembly is also widely used for compaction control (NF P94 063 standard) and meets the “Cofrac” requirements. The software supplied with the catalogue of soils issued by CER in Rouen makes this the most widely used constant energy machine for compaction control.

The success of this device is also due to the design of its dynamic probing system which is equipped with a motor system that is not supported by the drive rod. Apart from this advantage, the support on the drive rod during driving is very limited (in accordance with the requirements of the standards). Moreover, movement of the hammer is free over the whole height of the mast, its travel per blow is not limited.

Applications :
– Compaction control in accordance with NFP94-063
– Dynamic penetrometer soil investigation in accordance with EN 22476-2
– Sampling by probing in accordance with EN 22476-3

Dynamic probing system

Weight of dropping mass (adjustable):
Drop height:
Lifting system:
Blow frequency:
Travel per blow:
Dynamic probing system weight:

63.5 kg (10+20+20+13,5)
75cm, 50cm
Hydraulic via chain
15 – 30 blows/min
Entire height of the mast


Lifting system:
Lateral adjustment:
Stabilisation / support:

Hydraulic jack
Hydraulic jack
Hydraulic mast movement

Chassis / carrier

Drive mechanism:

Hydraulic, 2 speeds, proportional controls
Honda 12 hp hydraulic petrol engine
Orometer, 12V socket, headlight, tow ball



Hydraulic, automatic
10 tonnes


Transport mode (mm):
Working mode (mm):

L2450, l800, H1450
L2450, l800, H2200



Diameter 32mm
Fixed or lost cone, 20 cm²
Core, window sampler, SPT

Data acquisition (optional)


MSbox V2

Recording unit with GPS, can be connected to a PC/tablet via USB or Bluetooth, MSlog software for data processing, creation of reports: Geolocalisation of tests, reference curves for compaction control, insertion of documents into the report, automatic calculation of anomaly types.

Recording unit with 7» color screen, full azerty keyboard, GPS, WIFI and integrated camera. Allows a direct display of the penetrogram with the reference curves, the automatic calculation of anomaly types, the geolocation and the taking of photo for each test, an internet connection for sending the data. Delivered with Mslog software for PC data processing and creation of reports

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