Photo Elastic Transmission Polariscope Model MT 142

Sci-tech Photo Elastic Transmission Polariscope Model MT 142   is used to conduct photo-elastic experiments on plane, transparent plastic models. The models are subjected to load by external forces, and they are radiated by circular polarised light. An analyser analyses the light penetrating the body.

  The experimental setup comprises the separate components: a light source, two linear polarising filters (polariser and analyser), two quarter-wave filters and a frame in which the models are attached and subjected to load. The light source optionally permits coloured stress patterns with white light or a light/dark representation with monochromatic light.   The polariser includes a polarising filter and a quarter-wave plate and generates circular polarised light. Behind the model is a second quarter-wave plate (perpendicular to the first one), which is combined with a second polarising filter. These form the analyser. The filters are mounted on rotating bearings and fitted with angle scales.   Various polycarbonate models are mounted inside the frame. A load application device applies bending, tensile or compressive load to the model through a spindle. Stresses and strains occurring in the model are identifiable as bright spots, visualising the distribution of stress. The order of the dark isochromats is analysed to determine the principal stress differential. A wide selection of models such as notched bars, a wrench and a model-roller bearing or a rack-and-pinion is available as accessories. These ensure the implementation of comprehensive experiments. It is also possible to investigate your own models.

Size: 90cm x 70cm x 80cm (LxWxH)
Weight: 60 kg

Item Description

Features

  • Monochromatic or white light
  • Generate stress patterns with linear or circular polarised light
  • Models for specific problems can be prepared by the user

Photoelasticity is a proven method of analysing and recording mechanical stresses and strains in components. It is used both for quantitative measurements and for demonstrating complex stress states. The components used are models made of a transparent, photo-elastically sensitive plastic, which becomes optically birefringent under mechanical load.

Sci-tech Photo Elastic Transmission Polariscope Model MT 142   is used to conduct photo-elastic experiments on plane, transparent plastic models. The models are subjected to load by external forces, and they are radiated by circular polarised light. An analyser analyses the light penetrating the body.

The experimental setup comprises the separate components: a light source, two linear polarising filters (polariser and analyser), two quarter-wave filters and a frame in which the models are attached and subjected to load. The light source optionally permits coloured stress patterns with white light or a light/dark representation with monochromatic light.

The polariser includes a polarising filter and a quarter-wave plate and generates circular polarised light. Behind the model is a second quarter-wave plate (perpendicular to the first one), which is combined with a second polarising filter. These form the analyser. The filters are mounted on rotating bearings and fitted with angle scales.

Various polycarbonate models are mounted inside the frame. A load application device applies bending, tensile or compressive load to the model through a spindle. Stresses and strains occurring in the model are identifiable as bright spots, visualising the distribution of stress. The order of the dark isochromats is analysed to determine the principal stress differential.

A wide selection of models such as notched bars, a wrench and a model-roller bearing or a rack-and-pinion is available as accessories. These ensure the implementation of comprehensive experiments. It is also possible to investigate your own models.

Technical Specifications

Specifications

  1. Produce the mechanical stress curves through photo-elastic experiments
  2. 2 linear polarising filters (polariser and analyser)
  3. 2 quarter-wave filters for generating circular polarised light
  4. All filters have 360° angle scale and indicate the main optical axis
  5. Filters mounted on roller bearings and can be pivoted
  6. White light produced by a fluorescent tube and two incandescent bulbs
  7. Monochromatic light (yellow) generated by sodium vapour lamp
  8. Frame cross-members can be vertically adjusted
  9. Pressure or tensile forces generated by a threaded spindle
  10. Finished polycarbonate models available as accessories for the demonstration

  

Technical Specifications

Light source

lamp box with white diffuser for white light

  • 1 fluorescent tube TL-E 32W/33 (colour: 33)
  • 2 incandescent bulbs, candle lamp, frosted E14, 230V, 25W

for monochromatic light (yellow)

  • 1 sodium vapour lamp SOX 35, 35W

Filter, mounted in glass, diameter: Ø 425mm

  • 2 polarising filters (dark olive)
  • 2 quarter-wave filters (uncoloured)

Frame: WxH: 600x750mm

Mains supply: 230V, 50Hz, 1 phase

 

Experiment Possibilities

  1. Generate plane stress states in various models under load: bending, tensile load and compressive load
  2. Investigate stress distributions with linear or circular polarised light
  3. Interpret photo-elastic fringe patterns: stress concentrations, zero points, neutral strands, areas of constant stress and stress gradients
  4. Graphically and computationally determine the stresses

Model Number

MT 142