How to detect the defects in glass with a Polariscope strain viewer?

How to detect the defects in glass with a Polariscope strain viewer?

Polariscope strain viewer

Glass defects can occur for a number of reasons, including contamination, mechanical damage, or chemical influences. Contamination can come from a variety of sources, including dirt, dust, or other materials that come into contact with the glass during production. Regardless of the cause, any defects on the surface of the glass can affect its appearance and performance. Thus, it is important for you to test the defects present in glass products. We at Presto Testing Instruments have come up with one of the amazing lab testing equipment known as the Polariscope strain viewer for glassThis is one of the amazing lab testing equipment that is helpful in measuring the stress and strains that will be present in the glass products during the manufacturing process. Here in this blog, we are going to provide you the information about how you can easily detect the defects in glass with the help of a Polariscope strain viewer. But before that, we will discuss the Polariscope strain viewer. 

What is a Polariscope strain viewer and for what purpose it will be used?

Presto Polariscope strain viewer is the best and highly effective device to measure residual stresses and strains. It is used during the manufacturing process to assess the potential defect found in the product. 

The Presto Strain viewer is the most accurate and reliable way to measure residual stresses and strains, making it an essential testing instrument for quality control in manufacturing. When a product is manufactured, it is often subject to residual stresses and strains. These can have a significant effect on the strength of the product and may contribute to its eventual failure. In order to prevent this from happening, it is important to carefully control the manufacturing process. This includes ensuring that the materials are of the correct quality and that they are correctly heat treated. By doing this, it is possible to minimize the residual stresses and strains that appear on the product, helping to ensure its long-term success. This lab testing instrument is widely used in detecting the failure present in your products

Purpose of Polariscope strain viewer

Photo-elasticity is a major phenomenon that occurs in PET, Preforms, and Glass Products. Photo-elasticity means the change in the refractive index of the material when there is non-uniform strain distribution throughout the material. Photo-elasticity can be a great problem for the manufacturers of PET and glass products as this is a great flaw in the quality of the products.

Presto’s Adjustable Glass in Plastic Strain Viewer – Polariscope (PSPL-G20) is manufactured with wooden materials to provide an extended service life and accurate quality testing procedures. The testing instrument is provided with a smooth and attractive finish in brown color. The instrument is also provided with an instruction manual and a copy of the standard. Detect the glass strain with the help of a strain viewer for glass.

Below we have listed the features you will get with the Presto Polariscope glass strain viewer. 

Features of Presto Polariscope glass strain viewer

  • This device is simple to operate and easy to understand
  • The strain and stress are effectively measured for glass products.
  • The equipment is provided with the calibration certificate traceable to NABL labs
  • The machine has high-quality optics that provides a clear and sharp view.
  • Two light intensities were offered: Monochromatic light and Sodium Lamp.
  • Sharper and clearer optical viewing experience.
  • Standard Template for viewing a sample at 45º and 90 º angles.
  • Large Viewing glass area.

Technical Specifications of Presto Polariscope glass strain viewer

  • Working Space: 290mm and 440mm (Adjustable)
  • Diameter of Viewing Field: 190mm
  • Power Supply: Single Phase, 220V-240V, 50 Hz
  • Option of tilting the viewing area: Up to 180 degrees
  • Outer Body Construction: Wooden
  • Light Source: 2 Pin Fluorescent 9W cool white lamps.

With these features and technical specifications, it will be easy for you to determine the stress and strain present in the glass product. You can efficiently check the quality of glass products with a Polariscope strain viewer. Now, we will discuss how you can easily test the glass defects with the help of this lab testing instrument.

Steps to conduct the test using Polariscope strain viewer

If you want to commence the test easily then you need to follow some essential steps. Here we have listed those steps below:

  • Plugin the mains lead to an electrical socket of 3 pin-5 Amp configuration.
  • Clean the viewing area and test the platform.
  • Put the sample to be tested on the sample placement area by maintaining the center with respect to the viewing glass with its principal stress P in the horizontal or vertical direction. (The background of the viewer will be violet-red in color).
  • Put on the light source to test the sample.
  • Manually analyze the sample. It will reveal colors and these can be equivalent to optical retardation, in degrees.

In this way, you can easily test the sample with the help of a Polariscope strain viewer for Glass. Whenever you conduct the test using this testing instrument, then you should clean the viewing area and test the platform using a soft cloth. 

In this way, you can easily test the strains present in the glass with the help of a Polariscope strain viewer. If you want a live demo for this lab testing equipment, give us a call at +91-9210 903 903 or email us at Our team of technical experts will consult you regarding all your queries.