Error Analysis of the Oscillating Cup Method for Viscosity Measurements of Molten Salts

Abstract

The errors in viscosity measurements by the oscillating cup method were calculated as a function of the limit of accuracy imposed by the uncertainty in determining the constants of the oscillating system R, I, T0, δ0 and the limit of precision resulting from errors in determining the experimental parameters δ , T , h, ρ. Thus, by evaluating the fractional error of each of the parameters and implicitly its distinct contribution to the total standard error, it was established that the “meniscus error” Δh, which is difficult to be controlled or avoided, represents the major source of imprecision of oscillating cup viscometers.

Mathematical Models in High-Temperature Viscometry: A Review

“…where Bn is the Bingham number; κ and m are the flow consistency and the behavior indexes, respectively; We is the Weissenberg number; γ is the slip parameter; µ and µ are the dynamic polymer and solvent viscosities; σ is the second invariant of σ; the biviscosity model [40] is used in (15) and k σ is the model coefficient; the values of σ, P, etc., are dimensionless ones in contrast to (1)-( 9); the parameter γ ∈ [0, 1] [41], and the affine motion is for γ = 1 and the slip increases as γ decreases; the Maxwell model responds to (16) with γ = 1 and µ /µ ∼ 0; m < 1 for shear-thinning fluids and m > 1 for shear-thickening fluids.…”

“…Viscometric data on metal melts contain enough contradictions (e.g., the review in [13]), and the question of their reasons is a principal one for condensed matter physics. Experimental uncertainty and error analysis are the main problems for this method [14][15][16]. Furthermore, the study of the non-Newtonian behavior of metal melts is actively discussed in experiments with serially produced rotational viscometers [17,18].…”