Abstract: Specialized test equipment (STE) for aerospace product should be accurate, reliable and traceable, and it is recognized by both STE manufacturers and users.  Five traditional methods for calibrating STE are described. Because most STE have characteristics of operating complexity, excessive parameters and bad mobility, traditional STE calibrating methods are complicated, low efficient and expensive. A new method that portable and multifunctional calibrating instrument is applied to the field STE calibrating is introduced, and it is proved by two cases. At last uncertainty of the new STE calibrating method is analyzed.

Key words: Portable meter, Multifunctional calibrating instrument, Specialized test equipment, Uncertainty¹, Field calibration