Preproduction and current models of the miniature Wright peak flow meter have been compared with the standard Wright peak flow meter on normal and abnormal subjects. Early problems in production appear to have been overcome, and the current model agrees to within 3% with the standard peak flow meter, which is as close as the agreement between two standard instruments. The new mini-meter may be ...

Ocean current is one of the most important parameters in ocean observation, and measurement based on electromagnetic induction becoming more because its advantages such as simple structure high accuracy. However, it difficult to detect weak signals a complex marine environment. In this paper, an scheme lock-in amplification technology proposed. Key technologies evaluation induced intensity, ove...