GDS Hall Effect Local Strain Transducers

Product Code : GDSHE

On Sample Hall Effect Transducers (HE) are very light and easy to handle, therefore can be mounted to the sample for small strain measurement with minimal disturbance to the sample.

Small strain stiffness values are becoming more commonly required by consultants due to the parameters required for FE models.  It has been recognised for many years that small strain measurement is more representative to the operational strain, and that the small strain stiffness curve is required for any advanced modelling of the soil. Need advice choosing the right transducer, view our options table here.

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Key features Benefits to the user
Axial and radial deformation measured directly on the triaxial test specimen: Removes bedding errors or “end effects”.
Light compact semiconductor chip: The Hall Effect semiconductor chip is very light, has compact assembly and is compensated against changes in ambient temperature and changes in DC voltage supply.
Accurate determination of soil stiffness: True soil strains can be masked by deflections which originate in the compliances of the loading system and load measuring system. Such equipment compliance errors add to a variety of sample bedding effects to give a poor definition of the stress strain behaviour of the material under test, particularly over the small strain range.
Small strain measurement: Recent work has demonstrated that soils can be equally as brittle as rocks and that an understanding of their behaviour at levels of shear strain below 0.05% is very important.
Measurement is taken in the middle third of the sample which is less restrained than the end zones: Therefore, it is highly desirable that radial and axial deformations are measured locally in this region if realistic deformation moduli are to be found.
Displacement Range

+/-3.0mm

Pressure Range (MPa)

Up to 2000kPa

Sample Sizes

38mm, 50mm,70mm,76mm, 100mm,150mm, custom

Weight Approx (kg)

: Radial Caliper Weight, 38mm caliper = 24g, 70mm caliper = 46g, : Axial Apparatus Weight (1 off) = 16g, : Transducer Weight (1 off encapsulated Hall Effect Chip) = 5g