Determining soil moisture content by measuring the dielectric constant of the soil is not a new concept. However, determining the dielectric constant by measuring capacitance directly rather than through the use of time domain reflectometry (TDR) systems is a relatively new approach to soil moisture measurements. A unique probe assembly and a readout device that measures voltage drop and phase shift were developed and used for direct capacitance measurements. The ...
This report describes a patented method for using commercially available thermistors to make in-situ thermal conductivity measurements with commonly available thermistors to make in-situ thermal conductivity measurements with commonly available electronic equipment such as digital voltmeters. The emphasis is on the use of a single thermistor to measure the thermal conductivity of soils. Calibration techniques are explained and examples provided. Limits on this technique are discussed, including measurement range, material ...
Because of freezing point depression and isothermal springtime conditions, frost penetration measurements using temperature-sensing devices can become unreliable. In recognition of this problem two sensors that depend on changes in soil resistivity were tested. Tests were conducted under a parking area with an asphalt-concrete surface where salt was periodically applied as part of snow removal operations. For comparison, data were obtained from a resistivity probe, a thermocouple probe and a ...
The military has frequently encountered difficulty in installing and removing anchors in the field where hard frozen ground exists. This difficulty has often precluded rapid deployment of military hardware requiring anchors for their stability or support. This report gives results of a study of four commercial breaker-rock drills, a prototype hydraulic stake driver-retriever and a prototype propellant-actuated hammer which were evaluated for the driving of anchors into hard frozen ground. ...
The patent relates to a device for measurement of the volume flow of a watercourse by bridging the watercourse with a taut line and thereafter causing a floating instrumented package to traverse the watercourse, guided by said line. The instrumented package which contains means to ascertain the depth of the watercourse and separate means to measure the velocity of the watercourse, is remotely controlled from one bank of the watercourse. ...
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