In:
Vadose Zone Journal, Wiley, Vol. 18, No. 1 ( 2019-01)
Abstract:
Core Ideas Effects of air pressure on heat dissipation sensors previously unknown are quantified. Effects of air pressure are repeatable and consistent, therefore they can be removed. Changes in heat dissipation sensor calibration reduces error and decreases time of procedure. Heat dissipation sensors (HDSs) infer soil matric potential based on the measured rate of temperature rise from a heat source. The process for calibrating these sensors may use a pressure plate apparatus (PPA) to remove water to a certain calibration point that is controlled by pressure. Conventionally, the pressure within the PPA is released before the temperature change calibration points are measured (Δ T 0 ). This conventional HDS calibration approach can take several weeks. We propose that the equilibrated temperature change at pressure (Δ T p ) can be corrected empirically to the value at zero pressure. Based on measurements of 14 HDSs between 0.02 and 0.1 MPa, Δ T p was on average 6.2% larger than Δ T 0 . After pressure correction, using an empirical equation, the difference between the corrected Δ T p and Δ T 0 was only 0.28%. These results demonstrate that this empirical approach provides sufficient accuracy to achieve HDS calibration without performing a PPA pressure release.
Type of Medium:
Online Resource
ISSN:
1539-1663
,
1539-1663
DOI:
10.2136/vzj2019.05.0052
Language:
English
Publisher:
Wiley
Publication Date:
2019
detail.hit.zdb_id:
2088189-7
