A portable precision polarimeter for measuring compression at the physical edge, edge finish, or a selected location near the edge of flat and slightly curved glass.
Measure edge compression and near-edge tension in annealed, tempered, laminated, coated, and automotive glass. The portable GES-100 provides accurate, non-destructive stress measurement for plant-floor testing, laboratory inspection, and field evaluation.

Measure critical edge stress without cutting, modifying, or specially preparing the glass.

Use the instrument in a laboratory, on the production floor, or wherever the glass edge is accessible.

Read the compensator and use the supplied conversion table to determine stress in MPa, psi, or kg/cm².

Support edge-stress testing performed in accordance with ASTM C1279 and edge-compression requirements associated with ASTM C1048.
A portable precision polarimeter for measuring compression at the physical edge, edge finish, or a selected location near the edge of flat and slightly curved glass.
The standard GES-100 system includes:
– Microscope with 10× magnification
– Double-wedge compensator
– LED light source
– Edge-stress calibration plate
– Calibration certificate and stress-conversion table
– Practice sample for operator training
– Detailed operator manual
– Instrument-quality carrying case
The standard GES-100 is designed to measure compression at the glass edge using the double-wedge method. It is commonly used for heat-treated and tempered glass applications where edge compression is critical.
– 25 mm field of view
– Maximum glass thickness of 25 mm
– Standard retardation range of approximately 2,000 nm
– Optional range extender for very high stress levels
– Standard and high-sensitivity configurations available
The standard GES-100 uses a double-wedge compensator to measure compression at or near the physical glass edge. It is generally selected for tempered and heat-treated architectural glass.
Best suited for:
– Tempered architectural glass
– Edge-compression verification
– ASTM C1279 Procedure B testing
– ASTM C1048 quality-control applications
The GES-100-MWA uses a single-wedge compensator to measure both edge compression and near-edge tension. The standard configuration measures from the edge to approximately 50 mm inward, with a 100 mm version available. It is commonly selected for windshields and other automotive glazing.
Best suited for:
– Automotive windshields
– Sidelites and roof glass
– Near-edge tension measurement
– Laminated and curved automotive glazing
Either model can be supplied with a high-sensitivity measuring wedge for annealed and other low-stress glass.
The GES-100 platform can be configured for a wide range of stress levels and glass applications.
– Standard measuring wedge for heat-treated glass
– High-sensitivity wedge for annealed and low-stress glass
– Range extender for very high stress levels
– Battery-powered configuration for portable testing
– AC-powered configuration for stationary laboratory use
– GES-100-MWA version for near-edge tension measurement
Measurements can be taken at the physical edge, at the beginning of the edge finish, or a short distance inward using the extrapolation procedures described in ASTM C1279.
SEND US YOUR SAMPLES! If you are unsure which instrument is right for you or if Strainoptics can help you at all, send us samples! We will examine them and provide a feasibility report with our recommendations at no charge.