A hardness tester can be referred to as an instrument that measures the hardness of a specimen, normally by determining the impact on its surface through the use of a diamond, hard steel or carbide indenter.
Every tester makes use of a standardized technique of measurement. The measurement principles of the majority of the tester instruments are founded on either the computation associated with the force of rebound after hitting the tested specimen or the penetration of a diamond pyramid indentor onto the specimen being tested. Each tester is unique and has its advantages and enables accurate measurement of specimen hardness as per its technical specifications.
Types of Hardness Testing Instruments
Rockwell Hardness Testers: This is a tester for calculating the hardness of metallic and polymer items. The tester is utilized in indentation testing techniques and the indenter is usually either a hard steel ball or a conical diamond.
Macro and Micro-Vickers Hardness Testing Instruments: For the micro and macro-Vickers testers, a square-based pyramid diamond is utilized. An optical measurement system is used. For the macro-Vickers testers, loads used range from 5-50 kgs whereas for the micro-Vickers testers loads of between 10-1000 grm is used.
Brinell Hardness Testing Instruments: These testers are used in measuring the hardness of specimens that coarse or with a rough surface such as the castings. These testers use higher test loads of up to 3000 kgf.
Universal Hardness Testing Instruments: As indicated by their name, these testers can be used to measure the hardness of Vickers, Brinell, and Rockwell scales. Because of its adaptability, this tester comes with various kinds of indentor and measuring techniques of the imprints left.