Design of a Transition Resistance Measurement System
Sotu, Onome (2015)
Sotu, Onome
Hämeen ammattikorkeakoulu
2015
All rights reserved
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-2015052610295
https://urn.fi/URN:NBN:fi:amk-2015052610295
Tiivistelmä
ABSTRACT
The method described in the SFS-ISO 18594 Standard was implemented to design a transition resistance measurement system. Ohutlevykeskus, a partner of HAMK University of Applied Sciences and specialized in re-search, development and manufacturing to improve the competitiveness of Finnish sheet metal products, was the commissioning organisation of this thesis work. The transition resistance measurement system would meet the needs of ohutlevykeskus’ customers in the quantitative measurement of the surface conditions, as well as determine and ensure an acceptable standard of surface cleanliness of steel and aluminium products.
Limitations in the availability of reference models resulted in the conceptualization of a new and genuine design. The design consisted of a mechanical system which was assembled into a ZWICK/ROEL Z050 tensile test machine. The assembly was made up of a lower and upper structure of identical parts where the sheet whose resistance is measured is placed on a support between the electrodes. The major components of the assembly in-cluded the base-parts, electrode adaptor holders and electrodes with a final weight of 20.5kg
The design analysis revealed major bearing stress (up to 8.5MPa) located on the base-parts holding the electrodes. A material selection process, based on the stress calculations, electrical properties, and costs was con-ducted and nylon 6 (PA6) was selected as the material for the base-parts.
The resistance measurement circuit was designed using the Kelvin resistant measurement technique with the help of either a AEMC 6250 or Megger DLRO 10X micro-ohmmeter.
The designs were accepted as well as the technical documentation and a prototype of the system is being manufactured.
Keywords Transition resistance, measurement, design, spot welding, contact.
Pages 29 p. + appendices 1p.
The method described in the SFS-ISO 18594 Standard was implemented to design a transition resistance measurement system. Ohutlevykeskus, a partner of HAMK University of Applied Sciences and specialized in re-search, development and manufacturing to improve the competitiveness of Finnish sheet metal products, was the commissioning organisation of this thesis work. The transition resistance measurement system would meet the needs of ohutlevykeskus’ customers in the quantitative measurement of the surface conditions, as well as determine and ensure an acceptable standard of surface cleanliness of steel and aluminium products.
Limitations in the availability of reference models resulted in the conceptualization of a new and genuine design. The design consisted of a mechanical system which was assembled into a ZWICK/ROEL Z050 tensile test machine. The assembly was made up of a lower and upper structure of identical parts where the sheet whose resistance is measured is placed on a support between the electrodes. The major components of the assembly in-cluded the base-parts, electrode adaptor holders and electrodes with a final weight of 20.5kg
The design analysis revealed major bearing stress (up to 8.5MPa) located on the base-parts holding the electrodes. A material selection process, based on the stress calculations, electrical properties, and costs was con-ducted and nylon 6 (PA6) was selected as the material for the base-parts.
The resistance measurement circuit was designed using the Kelvin resistant measurement technique with the help of either a AEMC 6250 or Megger DLRO 10X micro-ohmmeter.
The designs were accepted as well as the technical documentation and a prototype of the system is being manufactured.
Keywords Transition resistance, measurement, design, spot welding, contact.
Pages 29 p. + appendices 1p.