With no method available for direct measurement of flow in open channel, hydrometrists use velocity and/or level (stage) as an indirect method of monitoring discharge. In most cases this requires a rating calibration in order to produce either stage-discharge or index velocity relationships, by conducting a series of current-meter gauging exercises. Similar calibration techniques are used if electronic velocity measurement systems e.g Doppler or transit time meters are installed, or whether a weir, flume or natural section is being rated. In all cases it is important to minimise the uncertainties involved in both the measurement and flow conversion process and this is where Hydro-Logic’s unparalleled experience in field hydrometry really counts. Our expertise extends to the following technologies:
- Calibration using current-meter gauging
- ADCP and transit-time meter specialists
- MCERTS inspection and audit
- Uncertainty analysis and theory
- Index velocity ratings for horizontal ADCP devices
- Weir crest-tappings for non-modular flow computations
- Gauging weir fish-pass design feasibility
- Review of ratings for networks
- Extension of ratings for flood flows
- Training courses in rating development.
