मृदा प्रतिरोधकता

नये स्थानों पर ग्राउण्डिंग प्रणाली (grounding system ) की समुचित डिजाइन करने के लिये वहाँ की मृदा प्रतिरोधकता (Soil Resistivity) का ज्ञान अति आवश्यक है। विभिन्न स्थानों पर मृदा की प्रतिरोधकता में बहुत अन्तर पाया जाता है, जिसके लिये नमी, ताप, तथा मृदा का रसायनिक संरचना का लग-अलग होना मुख्य कारण हैं। मृदा प्रतिरोधकता के सामान्य मान ये हैं- सामान्य मान : 10 से 1000 (Ω-m) असामान्य मान : 1 up to 10000 (Ω-m) मृदा प्रतिरोधकता का मापन विनर विधि (Wenner method) 4 pins The Wenner four-pin method, as shown in figure above, is the most commonly used technique for soil resistivity measurements.Two-dimensional Simulation of the Wenner Method with the Boundary Element Method - Influence of the Layering Discretization Rodrigo Dias Simone dos S. Hoefel Edmondo G. de A. Costa Jose A. M. Carrer Luiz A. de Lacerda Mecánica Computacional XXIX 2255–2266 15 November 2010http://www.csgi.unifi.it/~restauro/Prospezione%20geofisica_12.pdf Metodi di prospezione Geofisica University of Florence 18 अप्रैल 2016 https://web.archive.org/web/20120425092256/http://www.csgi.unifi.it/~restauro/Prospezione%20geofisica_12.pdf 25 अप्रैल 2012 dead http://www.voltimum.it/techarea.php?dyntype=hs&hsid=153&hpid=375 Guida alla realizzazione dell'impianto di terra Voltimum 18 अप्रैल 2016 https://archive.today/20130218142819/http://www.voltimum.it/techarea.php?dyntype=hs&hsid=153&hpid=375 18 फ़रवरी 2013 dead http://pangea.stanford.edu/research/groups/sfmf/docs/DCResistivity_Notes.pdf Tutorial : 2-D and 3-D electrical imaging survey M. H. Loke Stanford University 18 अप्रैल 2016 https://web.archive.org/web/20151222191411/https://pangea.stanford.edu/research/groups/sfmf/docs/DCResistivity_Notes.pdf 22 दिसंबर 2015 dead Using the Wenner method, the apparent soil resistivity value is: Analisi di impianti di terra a frequenza industriale: confronto tra indagine sperimentale e simulazione numerica Roberto Andolfato Lorenzo Fellin Roberto Turri Energia Elettrica Milan 74 2 123–134 http://webcache.googleusercontent.com/search?q=cache%3AEBYk5ipwnvUJ%3Awww.sintingegneria.com%2Findex.php%3Foption%3Dcom_phocadownload&view=category&download=5%3Al-energia-elettrica&id=5%3Apublications&Itemid=40&lang=it+andolfato+wenner+metodo&cd=3&hl=en&ct=clnk&gl=uk 4 March 1997 15 जून 2020 https://web.archive.org/web/20200213180137/http://webcache.googleusercontent.com/search?q=cache%3AEBYk5ipwnvUJ%3Awww.sintingegneria.com%2Findex.php%3Foption%3Dcom_phocadownload&view=category&download=5%3Al-energia-elettrica&id=5%3Apublications&Itemid=40&lang=it+andolfato+wenner+metodo&cd=3&hl=en&ct=clnk&gl=uk 13 फ़रवरी 2020 dead where ρE = measured apparent soil resistivity (Ωm) a = electrode spacing (m) b = depth of the electrodes (m) RW = Wenner resistance measured as "V/I" in Figure (Ω) If b is small compared to a, as is the case of probes penetrating the ground only for a short distance (as normally happens), the previous equation can be reduced to: स्लम्बर्गर विधि (Schlumberger method) Schl 4 pins In the Schlumberger method the distance between the voltages probe is a and the distances from voltages probe and currents probe are c (see figure above)। Using the Schlumberger method, if b is small compared to a and c, and c>2a, the apparent soil resistivity value is: where ρE = measured apparent soil resistivity (Ωm) a = electrode spacing (m) b = depth of the electrodes (m) c = electrode spacing (m) RS = Schlumberger resistance measured as "V/I" in Figure (Ω) इन्हें भी देखें भू-संपर्कन (grounding) श्रेणी:शक्ति प्रणाली श्रेणी:मृदा