Calibration of Tweezer Meters Enabling Sub 1 pF and Sub 10 nH
The importance of calibration for two-wire measurement setups is reaffirmed. For tweezer meters, this issue is critical due to the higher offset values, which can be as large as 19 nH.
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Authored By:
Michael S. Obrecht, Ph.D.
Siborg Systems Inc
Ontario, Canada
Summary
The increasing popularity of tweezer meters has highlighted the need for calibration tools to mitigate the inherent parasitic capacitance and inductance in test leads. Due to their similar mechanical design, most tweezer meters face the same limitations when measuring very small capacitance and inductance values, caused by these parasitic.
Properly compensating for parasitic effects is crucial for enhancing measurement accuracy and extending the measurement range. Parasitic capacitance can reach up to 0.3 pF, while parasitic inductance can exceed 15 nH, making accurate measurement of small components nearly impossible. These parasitics are influenced by the distance between the test leads - parasitic capacitance increases as the distance decreases, while parasitic inductance increases as the distance grows. A straightforward but effective calibration method is available to address these issues.
Conclusions
The importance of proper calibration for two-wire measurement setups is reaffirmed. For tweezer meters, this issue is even more critical due to the potentially higher offset values, which can be as large as 19 nH.
Initially Published in the SMTA Proceedings
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