Galvaanilise elemendiga mahulise niiskuse anduri integreerimine pinnase penetratsioonitakistuse mõõtmisesse
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Kuupäev
2026
Kättesaadavus
08.09.2026
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Penetratsioonitakistuse (Pr) mõõtmine on oluline mulla tihenemise ja läbilaskvuse
hindamisel, kuid Pr sõltub tugevalt mulla niiskusest. Seetõttu on Pr-andmete
tõlgendamine märksa usaldusväärsem, kui niiskust mõõdetakse samal ajal ja samas
mullakihis. Lisaks eeldab maastikuläbitavuse usaldusväärne hindamine nii mulla niiskuse
kui ka penetratsioonitakistuse arvesse võtmist. Käesoleva töö eesmärk oli välja töötada
tehniline lahendus mulla penetratsioonitakistuse mõõtmiseks, kus galvaanilise
elemendiga mahulise niiskuse andur on integreeritud mulla penetratsioonitakistuse
mõõtmisesse. Seade määras samaaegselt koonusele mõjuva rõhu, mõõtesügavuse
(laseranduriga), mahulise niiskuse (Cu–Zn elektroodipaariga) ning mõõtekoha asukoha
(GNSS-i abil). Niiskusandur on neutraalne mulla mineraalse osa mõju suhtes niiskuse
mõõtmisel, samas kui teiste alternatiivsete mõõtmismeetodite puhul mõjutab see mulla
niiskusandmeid märkimisväärselt. Galvaanilise niiskusanduri kalibreerimine viidi läbi
laboritingimustes (VWC 5–50%), tuginedes gravimeetrilisele võrdlusmeetodile. Seos oli
madalama niiskuse juures ligikaudu lineaarne ja kõrgema niiskuse juures mittelineaarne.
Soolsuse mõju katse näitas, et TDR-il põhinev võrdlusseade andis soolases mullas
niiskuse tugevalt ülehinnatud näidu, samas kui galvaaniliselelemendil põhinev mõõtmine
jäi gravimeetrilise meetodiga võrreldes realistlikku vahemikku. Tulemused näitavad, et
galvaanilise anduriga integreeritud Pr-mõõtmine loob praktilise eelduse Pr- ja
niiskusprofiilide samaaegseks kogumiseks ning on kasulik tingimustes, kus dielektrilisi
meetodeid mõjutavad soolsusest või mineraalsusest tulenevad häiringud.
Soil penetration resistance (Pr) measurement is important for assessing compaction and permeability; however, Pr is heavily dependent on soil moisture. Therefore, the interpretation of Pr data is significantly more reliable if moisture is measured simultaneously and in the same soil layer. In addition, reliable assessment of permeability requires consideration of both soil moisture and penetration resistance. The aim of this work was to develop a technical solution for measuring soil penetration resistance, where a volumetric moisture sensor with a galvanic cell is integrated into the soil penetration resistance measurement. The device simultaneously determined the penetration resistance acting on the cone, the measurement depth (with a laser sensor), the volumetric moisture (Cu–Zn electrode pair), and the location of the measurement site (GNSS). The moisture sensor was found to be neutral to the influence of the mineral part of the soil on moisture measurement, which in the case of other alternative measurement methods significantly affects the soil moisture measurement data. The calibration of the galvanic moisture sensor was performed under laboratory conditions (VWC 5–50%) based on a gravimetric reference. The relationship was approximately linear at lower moistures and nonlinear at higher moistures. The salinity effect test indicated that the TDR-based reference device gave a strongly overestimated moisture reading in saline soil, while the galvanic cellbased measurement remained within a realistic range compared to the gravimetric method. The results indicate that Pr measurement integrated with a galvanic sensor creates a practical prerequisite for the simultaneous collection of Pr and moisture profiles and is useful in conditions where dielectric methods are affected by salinity or minerality interference.
Soil penetration resistance (Pr) measurement is important for assessing compaction and permeability; however, Pr is heavily dependent on soil moisture. Therefore, the interpretation of Pr data is significantly more reliable if moisture is measured simultaneously and in the same soil layer. In addition, reliable assessment of permeability requires consideration of both soil moisture and penetration resistance. The aim of this work was to develop a technical solution for measuring soil penetration resistance, where a volumetric moisture sensor with a galvanic cell is integrated into the soil penetration resistance measurement. The device simultaneously determined the penetration resistance acting on the cone, the measurement depth (with a laser sensor), the volumetric moisture (Cu–Zn electrode pair), and the location of the measurement site (GNSS). The moisture sensor was found to be neutral to the influence of the mineral part of the soil on moisture measurement, which in the case of other alternative measurement methods significantly affects the soil moisture measurement data. The calibration of the galvanic moisture sensor was performed under laboratory conditions (VWC 5–50%) based on a gravimetric reference. The relationship was approximately linear at lower moistures and nonlinear at higher moistures. The salinity effect test indicated that the TDR-based reference device gave a strongly overestimated moisture reading in saline soil, while the galvanic cellbased measurement remained within a realistic range compared to the gravimetric method. The results indicate that Pr measurement integrated with a galvanic sensor creates a practical prerequisite for the simultaneous collection of Pr and moisture profiles and is useful in conditions where dielectric methods are affected by salinity or minerality interference.
Kirjeldus
Magistritöö
Tootmistehnika õppekaval
Märksõnad
magistritööd, penetratsioonitakistus, mullaniiskus, galvaaniline element, soolsus, penetromeeter