Demagnetization of instrument transformers before calibration

Calibration of Instrument Current Transformers with Atypical Secondary Current

− Methods enabling a determination of errors εI and δI for a high transformation ratio difference between a standard and tested instrument current transformers (ICT) are described in this article. A widespread method uses an automatic transformer test set for the measurement of a difference between a standard and tested ICT. A method transforming secondary currents to voltages and an indirect m...

Ferroresonance in Power and Instrument Transformers

This chapter describes the fundamental concepts of ferroresonance phenomenon and analyzes its symptoms and the consequences in transformers and power systems. Due to its nonlinear nature, the ferroresonance phenomenon can result in multiple oscillating modes which can be characterized based on the concepts of the nonlinear dynamic systems, e.g., Poincare map. Among numerous system configuration...

Inductive Voltage Transformers Calibration by the Parameters

The accuracy class of an IVT – Inductive Voltage Transformer – is typically assessed in laboratory installations either by comparing with another IVT presenting greater accuracy and traceable to a national laboratory or by using a capacitive divider. Calibration in the field using internal parameters is considered herein, using results obtained from typical open and short circuit tests and wind...

Lc-ms Instrument Calibration

As analytical and bioanalytical methods must be validated before using them for routine sample analysis and after changing method parameters (see Chapter 8), instruments such as liquid chromatography coupled with mass spectrometry (LCMS) or tandem mass spectrometry (LC-MS/MS), which are utilized to perform the analysis, should be calibrated and qualified. In addition, an instrument’s performanc...

Instrument Calibration Report