This essay provides a summary of “Advances in the Heat-Pulse Technique: Improvements in Measuring Soil Thermal Properties” recently appearing in Methods of Soil Analysis. Series

Horton, Robert

Liu, Gang

Lu, Yili

Ren, Tusheng

Wen, Minmin

English

This essay provides a summary of “Advances in the Heat-Pulse Technique: Improvements in Measuring Soil Thermal Properties” recently appearing in Methods of Soil Analysis. Series.This summary is published as Wen, Minmin, Gang Liu, Robert Horton, Yili Lu, and Tusheng Ren. "Summary of Advances in the Heat-Pulse Technique: Improvements in Measuring Soil Thermal Properties." Soil Science Society of America Journal (2018). doi: 10.2136/sssaj2018.02.0067.</p

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Soil Science Society of America Journal  Soil Sci. Soc. Am. J.  doi:10.2136/sssaj2018.02.0067 Received 5 Feb. 2018.  Accepted 28 Mar. 2018.  *Corresponding author (liug@cau.edu.cn). © Soil Science Society of America. This is an open access article distributed under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)Summary of Advances in the Heat-Pulse Technique: Improvements in Measuring Soil Thermal PropertiesMethods SummaryThis essay provides a summary of “Advances in the Heat-Pulse Technique: Improvements in Measuring Soil Thermal Properties” recently appearing in Methods of Soil Analysis. Series.Abbreviations: DPHP, dual probe heat pulse.The dual probe heat-pulse (DPHP) technique is used widely for in situ de-termination of soil thermal properties. Soil thermal properties, including thermal diffusivity (a), thermal conductivity (l), and volumetric heat capacity (C), have important influences on soil heat and mass transfer processes. Special care is needed to obtain accurate DPHP measurements in field soil, be-cause of potential problems of probe deflections, finite probe properties, thermal contact resistance, and influence of the soil–air interface. In a chapter of the recent Methods of Soil Analysis, the authors present a review of the theory, instrumenta-tion, and procedures needed for the DPHP sensor to obtain accurate in situ soil thermal property measurements (Liu et al., 2017).Probe-to-probe spacing, r, of a DPHP sensor is usually determined by cali-brating the sensor in a material with known heat capacity. Unfortunately, when a DPHP sensor is inserted into soil, the probes are likely to deflect (see Fig. 1), which changes the value of r. Uncertainties in r lead to erroneous determination of soil thermal properties derived from DPHP measurements. A novel strategy for determining in situ r values is available, which leads to accurate estimates of soil thermal properties. In addition to accounting for DPHP probe deflections, finite probe properties, thermal contact resistance, and influence of the soil-air interface must also be considered. Methods to account for each of these potential problems are described in detail, and the benefits derived from employing these methods lead to improvements in thermal property determinations.RefeRenceSLiu, G., M. Wen, X. Chang, T. Ren, and R. Horton. 2013. A self-calibrated dual probe heat pulse sensor for in situ calibrating the probe spacing. Soil Sci. Soc. Am. J. 77:417–421. doi:10.2136/sssaj2012.0434nLiu, G., Y. Lu, M. Wen, T. Ren, and R. Horton. 2017. Advances in the Heat-Pulse Technique: Improvements in Measuring Soil Thermal Properties. Methods of Soil Analysis 2. doi:10.2136/msa2015.0028Minmin Wen Gang Liu* Dep. of Soil and Water College of Resources and Environment China Agricultural Univ. Beijing 100193, PR ChinaRobert HortonDep. of Agronomy  Iowa State Univ. Ames, IA 50011Yili Lu Tusheng RenDep. of Soil and Water College of Resources and Environment China Agricultural Univ. Beijing 100193, PR Chinacore Ideas•	The dual probe heat-pulse (DPHP) method is used to measure soil thermal properties.•	Special care is needed to obtain accurate DPHP measurements in field soil.•	A review of theory, instrumentation and procedures needed is presented for DPHP.fig. 1. Schematic of the in situ probe spacing correcting heat pulse sensor with outward deflection of the temperature probe (modified from Liu et al., 2013), where ri is the deflected probe spacing of the ith thermistor; ri0 is the initial probe spacing of the ith thermistor; Δri is the displacement of the ith thermistor; li is the distance from the ith thermistor to the sensor body surface; and q is the deflected angle.Published online July 26, 2018

Summary of Advances in the Heat-Pulse Technique: Improvements in Measuring Soil Thermal Properties

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Summary of Advances in the Heat-Pulse Technique: Improvements in Measuring Soil Thermal Properties

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