This Soil Resistivity equipment utilizes the four electrode method developed by the National Bureau of Standards known as the Wenner 4-pin Method. The test determines the average resistivity of the soil to a depth equal to the spacing between electrodes (soil pins). This kit is designed for the maximum pin spacing of 20ft (6.1m) recommended for a standard survey.

HM-940 Soil Resistivity Kit consists of the Soil Resistivity Reel with four color-coded lead wires harnessed together, four Heavy Duty Soil Pins, and a Soil Box with leads for laboratory testing, housed in a sturdy, foam-lined plastic case. Lead wires plug into the reel hub and terminate with spring-loaded clamps at the opposite end. Soil Pins are 18x3/8in (457x9.5mm) stainless steel with T-handles. The plexiglas Soil Box for laboratory testing has removable potential pins of brass and current plates of stainless steel. HMA-672 Inside Dimensions: 9x2.5x1.5in (229x64x38mm), LxWxD. Set of four Soil Box Lead wires are 24in (610mm) in length. A soil resistivity meter is not included in this kit; it is designed to be used with the HM-942 Soil Resistance Meter, purchased separately. Est. Ship Wt.: 14lb (6kg).

HM-942 Soil Resistance Meter is purchased separately from the Resistivity Kit. When used together with the HM-940 kit, soil resistance values can be read directly from the analog dial of the meter; no calculations are necessary. The high sensitivity meter with eight ranges (0.1ohm-1.1megaohm) and a large dial for easy readability is powered by conventional C-cell alkaline batteries. A rugged weatherproof plastic case is IP67 rated, and measures 12x10x5in (310x250x125mm). Est. Ship Wt.: 10lb (5kg).