Tru-Blue II Digital Rockwell and Superficial Hardness Tester
Since 1984, United has manufactured computer-controlled closed loop Rockwell testers. Our second generation Rockwell tester, the Tru-Blue II is the lowest priced US manufactured closed loop tester that meets ASTM E18, ISO 6508 specifications and NIST recommendations. The Tru-Blue II comes standard with a direct certification of the hardware calibration with NIST traceability and a one-year indirect calibration for customer specified hardness scales. Along with a user friendly control panel, the tester can be put into operation without the need for an initial on-site calibration or manufacturer's assistance! Having no dead weights, pivot points and knife edges to move out of adjustment, the Tru-Blue II can be moved to a new location without having to be re-calibrated. When mounted on United's optional mobile stand, the Tru-Blue II becomes portable for use in different departments.
The importance of NIST Traceable Closed Loop Testing
A TRUE "CLOSED LOOP" hardness testing system like the Tru Blue II, offers a good sound approach for performing tests and virtually eliminating operator influence. This tester precisely controls all aspects of the test cycle. In addition to providing uniformity of testing, it provides the ability to automatically and electronically record each hardness test. Test reporting and data acquisition is accomplished by a printer and/or an IBM compatible computer. Using United's proven computer storage technology, records are easy to maintain and access. Like most of the mechanical testers made in the United States from around 1930 to recent years the United Tester can not have its calibration altered in the field, making it highly reliable and trustworthy. Below is a graph indicating the precise loading operations at HRC.