Category: Mechanical Testing

Measurements and Controls Mechanical Testing

Vision Gauge Digital Optical Comparator | Optical Comparator Measurement | Digital Optical Comparator Machine

By magnaparthi on 29/06/202008/03/2021

Vision Gauge Digital Optical Comparator / Profile Projector

The Vision Gauge Digital Optical Comparator is “The Fastest, Easiest, Most Accurate Way to Compare a Part to a CAD File. Vision Gauge Digital Optical Comparators are very robust. They are perfect for both the shop floor and the Quality Control lab. Standard 12″ travel X-axis stage with 0.5 micron resolution encoder and protective bellows around the 6” travel Y-axis column. All 3 axes (X, Y and Z) have high-accuracy crossed roller movements for optimal linearity and positional repeatability and high load carrying capability. Hard chrome plated X-axis stage, made of hardened tooling steel and with dual industry-standard dovetail grooves for easy part fixturing.

Vision Gauge Digital Optical Comparators are complete, ready-to-run Windows-based solutions and are delivered network-ready. They are available in both horizontal and vertical configurations. They have industry standard dovetail mounting grooves for easy part fixturing.

Vision Gauge Digital Optical Comparators are available with transmitted (i.e. back) and / or reflected (i.e. front) illumination. All illumination is LED-based for very stable and repeatable illumination conditions over a very long life (no more bulbs to replace!). Furthermore, the illumination is programmable and computer-controlled. Everything is done through a single simple an d intuitive software interface.

Vision Gauge Digital Optical Comparators have power focus. They are available in industry standard 5X, 10X, 20X, 50X and 100X optical configurations. They are available in both single and multi-mag configurations.

Vision Gauge Digital Optical Comparators and extremely easy to use. They are a “drop in” replacement for traditional optical comparators. An optional high-resolution LASER module is also available for depth & height measurements. Motorized fixtures and extended travels are also available.

What is a Profile Projector or Vision Gauge Digital Optical Comparator?

A Digital optical comparator or Machine Vision or Profile Projector is a comparator that tests products for defects and inadequate compliance using optics. This method can be managed electronically by the automated optical comparator, saving time and eliminating the need to manually collect data.

How Vision Gauge Works?

The concept behind an optical comparator can be compared to that of an old-school overhead projector. Remember those common transparent plastic transparencies projected on a projector in the classroom? In reality, an overhead projector can be used to create a basic comparator device.

You might try this little experiment if you can still find an overhead projector around the school, college, or office premises. To begin, position any two-dimensional component on the projector’s stage and project the image onto a large piece of paper pinned to the wall. A pen may be used to draw the shadow that is projected on the page. This pen outline serves as a baseline from which all subsequent items put on the stage can be measured.

They aren’t the same if the pieces don’t fit the drawing. As a result, the pen outline serves as a comparator template. We can’t even use an overhead projector to inspect pieces in practice. Overhead projectors are often position in a static, motionless location. The scale of the reference picture on the wall changes if the projection distance changes slightly as a result of the projector being disturbed or shifted, and your pen drawing becomes inaccurate.

The main idea behind an optical comparator for quality control is to take the overhead projector principle and bundle it all within a box so that the optical distance between the component and the panel is set, known, and can be calibrated.

Using a screen overlay or cross hairs as a reference point for projected points or edges, measurements of the component can be taken directly off the screen based on the known magnification of the lenses. The operator centers a point of interest on the cross hairs, then shifts the picture and records another point. Taking several points allows features like circles, slots, radii, and edges to be analytically constructed—typically using a microprocessor-based digital display.

Types of Vision Gauge

1D Vision Gauge
2D Vision Gauge
3D Vision Gauge
Area scan vs Line scan

1D Vision Gauge:

Instead of looking at the entire picture at once, a 1D vision gauge analyses a digital signal one line at a time. This methodology is widely used to identify and classify defects in continuous-process materials such as paper, metals, plastics, and other non-woven sheet or roll products.

2D Vision Gauge

Many popular inspection cameras conduct area scans involving the capture of 2D snapshots in different resolutions. Another form of line scan for 2D computer vision creates a 2D image line by line.

3D Vision Gauge

3D machine vision systems usually consist of several cameras or one or more laser displacement sensors which offers component orientation knowledge to the robot and they are positioned at different locations and traingulation position in 3D Space.

Area scan vs Line scan

Line scan systems include many distinct advantages over area scan systems in many industrial applications. Inspecting round or cylindrical parts, for example, can necessarily require the use of multiple area scan cameras to cover the entire part surface. Rotating the section in front of a single line scan camera, on the other hand, unwraps the image and captures the entire surface.

For example, once the camera has to look through the roller on a conveyor to see the bottom of the component, line scanning systems fit more easily into confined situations. In general, line scan cameras have a much higher resolution than conventional cameras. Line scan systems are well-suited for products in continuous motion because they involve moving parts to build the image.

Benefits of Vision Gauge:

Produce a very high contrast image with very sharp edge profiles so that there is no problem viewing it in full daylight.
Are much more accurate
Allow the user to be much more productive and get more work done with a single machine
Have “Auto Pass / Fail”
Can compute and display the part’s deviation from nominal and compare it to bi-directional tolerances
Work directly with the CAD data so that no overlays / templates / Mylars are required
Can be used to collect images (either with or without the CAD data overlay and with or without annotations), measurements and data .
Can also carry out fully automated measurements (like a video CMM)
Have a smaller footprint and use less floor space
Can be moved much more easily and without requiring re-calibration (i.e. “rolling cart” configuration is standard)
Have a much greater optical depth of field, i.e. “everything is in focus all at once”
Have a longer optical working distance ( i.e. more clearance between the part and the lens)
Allow you to compare a part to its CAD data beyond the optical field-of-view ! (because the CAD data tracks the part and follows the stage motion )
Have LED illumination for very stable illumination over a 10 year life. No more bulbs to change

Mechanical Engineering Mechanical Testing

MECHANICAL TESTING | Mechanical Testing of Materials | Mechanical Testing of Metals | Mechanical Testing of Welds | Mechanical Testing Facilities | Load & Tensile Test | Mechanical Testing Machine

By magnaparthi on 25/05/2020

Various tests:

Tensile Test:

A tensile test, also known as a tension test, tests a material’s strength. It’s a mechanical test where a pulling force is applied to a material from both sides until the sample changes its shape or breaks. It’s is a common and important test that provides a variety of information about the material being tested, including the elongation, yield point, tensile strength, and ultimate strength of the material. Tensile tests are commonly performed on substances such as metals, plastics, wood, and ceramics.

Tensile testing systems use a number of different units of measurement. The International System of Units, or SI, recommends the use of either Pascals (Pa) or Newtons per square meter (N/m²) for describing tensile strength. In the United States, many engineers measure tensile strength in kilo-pound per square inch (KSI).

Tensile test with electronic extensometer

This instrument is to be used on Tensile or Universal testing machines to find out Proof stress & Young’s modulus values. In case of many brittle materials such as high carbon steels, alloy steels, light aluminium & magnesium alloys, it is difficult to get yield values. For such materials stress corresponding to a certain allowable amount of plastic deformation is termed as proof stress say 0.1% or 0.2% proof stress. The measuring range is up to 5mm & resolution is 0.001mm.

Tensile testing at elevated temperature.

High temperature tensile testing is a procedure to test the properties of a material at above room temperature. It will determine the following parameters:

Tensile strength (breaking strength)
Yield strength
Elongation
Reduction of area

Specialist testing, measurement and control equipment is required to perform this test.
The results of such a test will provide a good indication of the static load bearing capacity of the material and therefore establishes the suitability of a material for its intended purpose.

Tensile test on Tor steel Bars

TOR steel is one of the best grade of steel used in concrete reinforced. It’s a kind of high adherence steel. Other types of steel are used for less resistance concrete. Thermo mechanically Treated (TMT) bars are a type of corrosion resistant steel reinforcing bar used in concrete construction.

Bend test on plates

A bend test is used to determine whether a specific piece of metal in question will break or fracture under pressure. This is important in the construction of any project using metal, otherwise the building or the item being made could collapse from the immense pressure exerted on it. Every piece of metal made cannot be tested, therefore certain pieces are tested and if they pass, the other pieces are made using the same process. The results of a bend test are reported differently depending on the type of material tested. There is no standard method for reporting the durability that applies to all materials, rather each group has its own set by which it is judged and compared to other metals in that group.

The bend test is essentially measuring a metal’s ductility. Ductility defines how easily a metal can bend without breaking. The higher the ductility of a metal, the more it can bend without breaking or becoming deformed from its original shape. This is important because certain metals must handle pressure without snapping yet still be ductile enough to bend slightly and not lose their support or shape. Copper and steel are two metals that have a high ductility and do well under pressure.

Bend test on pipes

Bending tests are carried out to ensure that a metal has sufficient ductility to stand bending without fracturing. A standard specimen is bent through a specified arc and in the case of strip, the direction of grain flow is noted and whether the bend is with or across the grain.

Bend Test on Tor steel

The purpose is to make certain the weld and the base metal are properly fused, and that the weld metal and the heat affected zone (HAZ) have appropriate mechanical properties

Re-Bend test on Tor steel

The purpose of re-bend test is to measure the effect of strain ageing on steel. Strain ageing has embrittlement effect which takes place after cold deformation by diffusion of nitrogen in steel. Hence, there is limitation stated in some design codes to restrict the nitrogen content of steel to 0.012%.

Nick Break Test

The NICK-BREAK TEST is useful for determining the internal quality of the weld metal. This test reveals various internal defects (if present), such as slag inclusions, gas pockets, lack of fusion, and oxidized or burned metal. To accomplish the nick-break test for checking a butt weld, you must first flame-cut the test specimens from a sample weld.

Posted in: bend Test, Load & Tensile Test, Mechanical Testing Facilities, Mechanical Testing Machine, Mechanical Testing of Materials, Mechanical Testing of Metals, Mechanical Testing of Welds, Nick break test, rebend test, test on bars, test on plates, test on sheets