What Is a Universal Test Machine?
A modern Universal Test Machine (UTM) is a highly accurate, precision-measurement device used to apply tension and compression forces to a variety of materials, parts, and finished products. Modern UTM’s can apply these forces at very precise speeds and due to advances in technology many other parameters can now be incorporated into a test procedure. Measurement parameters such as Stress and Strain, break detection, yield point, elongation, load holding, cycle testing, and many other procedures are now common on Universal Test Machines.
However, not all Universal Test Machines are created equally. Some Universal Test Machines can apply a wide range of test parameters to samples while others may only be capable of applying a single test parameter. For example, not all Universal Test Machines are able to measure Stress, Strain, or Yield Point, so careful consideration should be given to what calculations are important to your test procedure as you evaluate different UTM’s.
The sample being tested on a Universal Test Machine can range from the most advanced synthetic fiber or metal alloy to a finished part or product from any industry. Practically any part or component that will fit on a Universal Test Machine can likely be tested. If samples do not fit on a standard Universal Test Machine having a UTM custom built is common and often the only way to properly test large samples.
History of Universal Test Machines
UTMs have been around for well over 150-years and have played an integral part in the evolution of new materials as well as finished parts and products from every industry. Development was largely driven by the Industrial Revolution of the mid-1800’s and the increasing use of iron and steel in industrial applications.
While the UTM began as tool to measure the strength of Iron and Steel, it has evolved into a tool to measure the strength and material properties of many other materials such as plastic, rubber, fabric, wood, and composite materials such as Nylon or Kevlar. Just like the microscope revolutionized biology when it was invented, the UTM helped revolutionize a new field of Engineering known as Materials Science. This field of science has evolved into a combination of many fields devoted to the study and understanding of new and existing materials.
The Role of a Universal Test Machine
Once a new material, product or part is developed one of the first questions asked is, how strong is this new part or material? This fundamental question is the essence of why the UTM was developed and why they are still used so frequently across so many different industries. Like all instruments used in scientific measurement, the UTM began as a simple device that has evolved into a highly complex system of components, some of which are unique to a specific material, product or test standard.
The basic components of a modern UTM include
- Test Frame
- Load Cell
- Cross Head
- Strain measurement device (if this measurement is required)
- Data Recording and output device which has evolved to mean software
- Grips & Fixtures used to hold the sample for testing
Careful attention should be given to each component so that accurate, reliable, and repeatable testing can be performed.
How to Determine the Proper Test Procedures
In most cases the test procedure you choose to implement will be based upon a published test standard, or a set of specifications that have been developed internally based on proper R&D, quality control and statistical analysis.
There are literally thousands of test standards available for consideration when one factors in the different governing bodies and variations that exist between each. Specific standards exist for certain materials such as Steel, Plastic, Rubber, Wood, Paper and Composites. Test standards are very detailed and govern such things as sample size, sample preparation, test speed, calculations to be determined, test frame specifications, accuracy requirements, and many other variables to ensure accurate and repeatable testing procedures.
Most test standards are developed by a committee of industry professionals with varying backgrounds. Standards are reviewed by committees on a frequent basis and they are updated regularly. Some of the more common test standards are published by the following organizations, but several industry-specific organizations also publish standards. Examples are listed below.
- ACI - American Concrete Institute
- ANSI - American National Standards Institute
- API - American Petroleum Institute
- ASTM - American Society for Testing and Materials
- BSI - British Standards institute
- CEN - The European Committee for Standardization
- DIN - German Institute for Standardization
- GB – Chinese Test Standards
- ISO - International Organization for Standardization
- JIS - Japanese Industrial Standards
- TAPPI - The Technical Association of Pulp and Paper Industry
Why United Testing Systems?
United Testing Systems has been manufacturing Universal Test Machines since 1964. Our experienced engineers and sales staff can provide you with detailed information on which test system will work best for your particular needs and challenges. Capabilities and prices of Universal Test Machines vary widely across our industry and United prides itself on being able to save our customers tens of thousands of dollars versus our competition.