Skip links

Inertron is a mass properties measurement device. It accurately computes mass , center of gravity, moments and products of inertia (MCI). In less than a few minutes rather than several days for classic methods.

  • Accuracy: 0.1% of sensor’s full scale
  • Easily scalable up or down: 10kg, 100kg, 1000kg, 10 000kg
  • Easy to move close to object
  • Plug and play (230V)


A top plate stands on a hexapod which legs are attached to eccentric gears linked together by a central gear.
The object to measure is clamped to the plate.
The central gear is driven by a single motor, creating a totally reproductible periodic kinematic.
The 6 hexapod legs carry axial force transducers which measurements are sampled on pre defined positions during each cycle.

For each angular position:

  • The 6 force sensors allow to compute the plate and object forces torsor
  • T = P + a . v² . MCI where
    • P is the weight torsor
    • a . v². MCI is the Inertia torsor , proportional to MCI and square v as of angular speed

Measuring T for 2 different angular speeds, P and MCI can be computed

Measurement only takes a few minutes. It yields the complete object MCI:

  • Mass
  • Center of gravity coordinates in plate’s referential
  • Inertia matrix : complete with moments and products

A specific interface between the plate and the object may be necessary. In which case, a deadweight measurement with the interface but no object can be subtracted from the complete measurement

  • Inertron is equipped with geometry and force sensors that define the product limit: mass of the object * height of its center of gravity.
  • We offer three standard configurations: Inertron 1.5-100, Inertron 3-1000 and Inertron 5-5000.
  • For each standard configuration, two operating points are given as an example which allow the full scale of the force sensors to be used:
  • For each configuration, it is possible to reduce the capacity of the sensors if better precision is desired for lower masses.
  • Inertron ensures a very good relative accuracy for masses 10 times lighter than maximal masses of each configuration
  • For other masses or heights of CDG, a personalized definition is possible on specifications.

Measurement accuracy

  • 240 samples per cycle for each of the 6 transducers
  • Automatic angular speed adjustement to maximize transducer’s range usage without overload:
    • Low for heavy objects
    • High for light objects


  • 2 rotational speed setpoints each with 10 cycles = 240x6x2x10 = 28 800 recorded force values
  • Each MCI is a linear combination of all the measured forces
  • The signal to noise ratio is thus improved by two orders of magnitude ( 20dB)
  • The measurement principle automatically filters out solid and aerodynamic friction


  • 0.1% of sensors ’ full scale
  • Successive measurements of reference object configurations over the measuring range are used to calibrate the device.

  • By measuring the largest possible set of reference object configurations, we can:

    • Check forces to MCI linearity

    • Compute uncertainty of measured MCI, allowing Inertron accuracy evaluation

Key features

  • Dimensions are proportional to measured object (weight)
  • Easily scalable up or down: 10 / 100 / 1.000 / 10.000 kg
  • Inertron can operate upside down to measure objects held from the top
  • All axes in a single measurement
  • Smaller models can easily move to the object to measure and are powered v i a single 230V socket
Inertron boat
  • Significantly reduced measurement time
  • Failed transducers: Inertron can still run with a slightly degraded accuracy E.g.: 2 failed transducers over 6 ~ 20 % accuracy loss
  • Continuous signal analysis allows backlash detection
  • No risk to tested object
  • Patented, designed, manufactured and maintained in France

Do you have a plan?

Contact Us


Hydraulic generation
Hydraulic generation
Electronic modules
Electronic modules
Return to top of page