Thermal Expansion and Its Effect on the Normal Force for a Modified Force Rebalance Transducer
Carl R. Schultesiz, G B. McKenna
Prior work in this laboratory [Niemiec, et al, J. Rheology, 40, 323-334 (1996)] showed that anomalous normal forces could arise in rotary shear measurements when thermal expansion of the force rebalance transducer (FHT) superimposed a squeezing flow on the shear flow. Transducer heating results from the current to the magnetic coils in the FRT necessary to counteract the applied torque. Partly due to this work, the manufacturer redesigned the transducer by replacing stainless steel components with Invar, an alloy with a very low coefficient of thermal expansion. Tests on the new transducer show that the thermal expansion is significantly reduced. The behavior of the new transducer is described.
force rebalance transducer, rheometer, thermal expansion
and McKenna, G.
Thermal Expansion and Its Effect on the Normal Force for a Modified Force Rebalance Transducer, SPE ANTEC Proceedings, New York, NY, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=851520
(Accessed December 10, 2023)