A procedure for resolving thermal artifacts in pressure transducers

作者：Moore Mitchell F; Vasconcelos Jose G^*; Zech Wesley C; Soares Elis P

来源：Flow Measurement and Instrumentation, 2016, 52: 219-226.

DOI：10.1016/j.flowmeasinst.2016.10.010

• Pressure transducer
• Temperature effects
• Pressure head
• Measurement error
• Stream flow

Many watershed studies rely on pressure transducers to measure and report stream and groundwater levels in order to characterize the hydrology of the region. The accuracy of pressure transducers in some applications have recently been questioned in studies reporting artificially exaggerated high or low pressure readings that cannot be explained by daily hydrological fluctuations. In a watershed field investigation, data analyses have revealed, for some sensors, patterns of artificial changes in stream and groundwater levels as a function of water and atmospheric temperature. These patterns do not follow the expected variation that could be caused by natural phenomena (i.e. changes in head caused by evapotranspiration). Laboratory analyses of temperature induced artificial pressure changes reproduces this error and yielded functional relationships for thermal artifact corrections. Using these relationships, stream and groundwater levels can be back-calculated yielding a more accurate watershed hydrologic characterization. By removing the thermal artifacts from laboratory and field data, errors are reduced by up to 65% (laboratory) and 81% (field data). The developed procedure can be used in other settings where pressure transducers are used, such as studies in rainfall/runoff variations, runoff measurements in urban settings, and the impacts of new development in rural watersheds.

• 出版日期2016-12