Abstract:
The main purpose of this work is to present the modifications and improvements performed on the 10kN deadweight machine installed at the Force, Torque and Hardness Laboratory of the National Institute of Metrology, Standardization and Industrial Quality – INMETRO. This work is also an extension of a previous IMEKO paper [1] where this same machine has been characterized. A series of modifications were implemented in the machine along the years. These modifications consisted mainly of switching the loading frame from two columns one to a set of three columns. Also, the installation of a mass leveling and centralization system was performed and an automatic supporting for its loading frame was installed . The data acquisition system , which was previously done manually by readings of the digital display of the machine is now done through a computer using a dedicated software. This software is able to control and manage the movement of the loads according the standards ASTM E 74.[2], NBR 6674 [3] and ISO 376 [4]. After these modifications, the measurement uncertainty was evaluated and compared to the previous value for that machine. It could be then observed a significant decrease on this value of about 90% from the previous value obtained. The modifications in the machine also lead to a series of tests performed and the Best Measurement Capability(BMC) was then determined.
