Abstract
Cross correlation techniques are becoming widely used for pipeline flow velocity measurement. Usually a polarity cross correlation method is employed because of its simplicity, but at the expense of losing information compared with a direct cross correlation method. This paper describes a direct cross correlator based on a Transputer1 which uses 8-bit data in the calculations. To reduce the discrimination error, a quadratic curve is fitted to three sample points around the cross correlation peak, and the delay time is interpolated. The cross correlation software is highly intelligent with automatic selection of transducer type, circuit gain, sampling frequency and pre-delay. Experiment results show that the cross correlation peak can be positioned in the middle of the correlation delay range by means of one of two automatic functions, and the measurement accuracy is 1%.
Original language | English |
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Pages (from-to) | 77-84 |
Number of pages | 8 |
Journal | Flow Measurement and Instrumentation |
Volume | 8 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1998 |
Keywords
- Cross correlation
- Velocity measurement
- Instrumentation Design