Method for measuring wall thickness of protective pipes for protecting contact thermometer utilized in process measurement technology, involves determining material thickness of protective pipe from resonant frequency of pipe

摘要

The method involves removing a temperature probe, and guiding a round metallic rod (2) into a protective pipe (1) for electrically conductive bottom contact. Alternating voltage of variable frequency is applied at the rod and at the protective pipe at height of a connecting head. Resonant frequency of the protective pipe is determined by determining the frequency of the alternating voltage. Material thickness of the pipe is determined from the resonant frequency. The determined resonant frequency is compared with computed resonant frequency to determine the thickness.