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Abstract The calibration test had been carried out to improve the accuracy of Time Domain Reflectometry (TDR) sensor measurements. The effect of dry density，structure properties and soil texture on soil-water content measured with the TDR sensor is explored，and the related mathematic correction models are established，on the basis of the comparative analysis of soil-water content of Q3 loess and paleosol measured by TDR sensor and oven-drying method. The test results indicate that，the use of the factory-supplied parameters resulted in overestimation of soil-water content compared to the oven-drying soil-water content，and the effect of dry density variation on the sensor measurements should not be neglected；The correction model of TDR sensor soil-water contents is established by considering the effect of dry density. It is proved that the correcting results of using the correction model is superior to the cubic fitting equation of regression analysis between θv and θw determined in the laboratory，and when the volumetric water content range is from 9.2% to 39.9%，the adjusted soil-water content is within 2%，and within 3% when the volumetric water content range is from 39.9% to 46.3%. No statistically significant difference of soil-water contents was observed between the undisturbed and the remoulded samples，and therefore the calibration test in laborary can substitute for in situ test；there are notable differences between loess and paleosol in soil texture and therefore the calibration model should be established respectively.
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2015, Vol. 34 
