Hioki RM2610, Instruction Manual

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About the reduction factor
8.1 About the reduction factor
In iterative calculations performed as part of an inverse problem analysis, calculations exhibit
unstable convergence if the initial value differs greatly from the solution (making it more likely to
encounter an error in which the interface resistance or composite layer volume resistivity is reported
as a negative value).
As shown by the line labeled “Large reduction factor” in the graph, a calculation error results when
the iterative calculation is subject to excessive correction, resulting in a negative resistance value.
Adjusting the reduction factor in such cases may stabilize the iterative calculation.
The reduction factor is a parameter that regulates the magnitude of correction performed in the
iterative calculation. The initial value of 1.0 results in maximum correction. Reducing this value (it
must be greater than 0) has the effect of reducing the magnitude of correction, with the result that a
phenomenon in which iteration undergoes too much correction can be reduced as shown in the line
labeled “Small reduction factor” in the graph.
However, smaller reduction factors increase calculation times since more iteration is needed in
order for calculations to converge. Consequently, it is recommended to use the initial value of 1.0
for the reduction factor when convergence is table.
Interface resistance (composite layer volume resistivity)
Iteration number
Small reduction factor
Large reduction factor
Calculation error
(negative resistance value)
Calculation times: Longer
Calculation stability: Higher
Calculation times: Shorter
Calculation stability: Lower
Reduction factor
Small (>0) Large (≤1)