Gilson Gilson HM-942 Analog Resistance Meter

The soil resistivity equipment adopts the four-electrode method developed by the National Bureau of Standards,namely the Wenner four-needle method. This test measures the average resistivity of soil to a depth equal to the spacing between electrodes (soil needle). This device is designed for the recommended standard survey of a maximum needle spacing of 20 feet (6.1 meters). The HM-940 Soil Resistivity Kit includes a soil resistivity roll with four color lead wires harnessed together,four heavy-duty soil pins,and a soil box for laboratory testing,housed in a rugged,foam-lined plastic box. The lead is inserted into the reel hub and the end is clamped with a spring. The soil pin is an 18x3/8in (457x9.5mm) stainless steel T-handle. Plexiglas soil boxes for laboratory testing have removable brass potentiometer needles and stainless steel current plates. Internal dimensions: 9x2.5x1.5in (229x64x38mm),LxWxD. Set of four soil box leads,24 inches (610mm) long. This kit does not include a soil resistivity meter; it can be used with the optional HM-942 soil resistivity meter. "," The HM-942 Soil Resistance Meter is purchased separately from the resistivity test kit. When used with the HM-940 kit,soil resistance values can be read directly from the meter's analog dial; no calculations are required. The 8-range (0.1 Ohm-1.1 Megohm) high-sensitivity meter and easy-to-read large dial are powered by traditional C-cell alkaline batteries. Rugged plastic housing,IP67 rated,measures 12x10x5 inches (310x250x125mm). Boat weight: 10 lbs (5 kg).