In this paper, the liquid level measurement of sealed air-condition compressor is introduced and an ultrasonic testing system based on virtual instrument is developed.

The state's top-level celadon-glazed dish, a masterpiece of Ge kiln porcelain from the Song Dynasty, was squeezed by a testing instrument due to human error, the museum said in a statement on Sunday.

With integration of DDS and computer technology, the tone burst instrument is well designed to meet the new testing standard of the sound level meter.