Fabric Analyser - Specifications

Multi-purpose Fabric Analyser (G50)

Image resolution of 5-100µm pixels suitable for geological or glaciology samples with 50mm objective lens. Other magnifications are optional.
Incorporates polariser filters, quarter wave plate, RGB LEDs for illumination about vertical axis, white LEDs illumination for inclined axes.
Acquisition time 50s for 200x200 output pixels, 4min for 1000x1000 output pixels using a 1GHz PC system.
Section thickness 0.2 to 1mm for ice, standard 20 to 100um for quartz or apatite, less than 30um for calcite.
The camera is a Prosilica GE 2040 machine vision camera.
The stage is 100x100mm computer controlled and you can define the area where you want to undertake analysis.
Dark Field illumination identifies boundaries, fluid inclusions, etc.
Scanned images stored on CDs or DVDs can be analysed by anyone who has a copy of the INVESTIGATOR free-ware.

NB. this has been superseeded by the G50 v5.4 instrument but operates on same principal and is described in Wilson et al. 2007.

Options of using 10x, 25x or 40x, and 100x lenses.
With standard lens system you have option of producing images with resolution of:-
- 0.3mm (300µm) field of view
- resolution of 0.5µm for individual pixel (NB. wavelength of light is 0.5µm)
With 100x objective lens, field of view is 0.1mm (100µm) and detailed analysis in 5µm diameter grains - the resolution is 0.2µm per individual pixel - can be undertaken (NB. It should be noticed that a normal thin section is 30µm thick, using this technique thickness is NOT critical).
Light source is an array of nine individual LEDs. This light source and the fabric analysis is controlled by algorithms that specifically relate to this system.
Over 300 images are produced over any selected area. These are combined by the computer to produce an AVA diagram and this is the starting point for the fabric analysis.
Every pixel that makes up the AVA is then used to produce a Schmidt scatter diagram. For example, 200,000 unique c-axes (each pixel) can then be plotted on a Schmidt diagram in 15 seconds.
Two options for fabric analysis, INVESTIGATOR analysis of scanned images or in-situ (real-time) analysis of selected areas which can be applied to in-situ experimental observations.