Analysis of a Portable, One Hundred Ampere Pulse Test Current Microhmmeter

Publication Year:
Usage 46
Downloads 43
Abstract Views 3
Repository URL:
Allred, John Marshall
Florida Technological University
Electric measurements; Ohmmeters
thesis / dissertation description
This report is an analysis of the Model RT-2 Microhmmeter which is a portable apparatus using a pulse current power source in the measurement of load resistances in the microhm range. The need for accurately measuring resistances in the microhm range is quite real for testing electrical power circuit breaker contact resistance. Both during acceptance checking within the manufacturing process and in the field for preventative maintenance, contact resistance must be accurately determined. Before the invention of the Model RT-2 Micrometer, no device existed which could accurately measure resistances in the microhm range that was readily transported by an unaided individual. The design of the Model RT-2 Microhmmeter is based on a specification set derived from user requirements, and ANSI C37.09. In addition, a weight limit of 25 pounds for the portable apparatus was imposed by the designer which included the weight of the self-contained power source. This paper suggests changes that will result in both weight and power consumption savings. A major change in the high current power supply circuit is suggested that will allow the microhmmeter to be a more versatile piece of test equipment. The Model RT-2 Microhmmeter is operational and has been successfully proven in the field. By using the portable microhmmeter, the reduction in the amount of time required to determine contact resistance can result in appreciable cost savings to the user.