Abstract: Certain disclosed embodiments provide sensing devices of the type useable to obtain measurements from a plurality of positions of a substrate, such as in a well, body of water, soil, snow pack, or ice pack. In a particular implementation, the sensing device includes a housing having a length. A plurality of digital sensors are disposed at a plurality of positions along the length of the housing. A communication bus is in communication with each of the plurality of sensors. A data collection or transmission device is in communication with the communication bus. Further implementations provide sensing devices having a housing formed from a plurality of modular sections. Sensors are disposed in at least one of the modular sections. Also disclosed are networks formed from a plurality of the disclosed devices.

Abstract: Photoacoustic instruments and their methods of use are disclosed. Certain disclosed photoacoustic instruments include a resonator cavity, an acoustic detector, a laser, an optical power detector, and a scattering detector. Further disclosed photoacoustic instruments include a resonator cavity, an acoustic detector, an optical power detector, a plurality of laser beams, each laser beam having a different wavelength, and, optionally, a scattering detector.

Abstract: A sensor system comprises a first sensor, a second sensor, and circuitry. The first sensor collects non-frozen liquid with a first collection efficiency, but does not collect frozen liquid. The second sensor collects non-frozen liquid with a second collection efficiency and also collects frozen liquid. The first collection efficiency and the second collection efficiency are substantially equivalent. The circuitry maintains the first sensor and the second sensor at a substantially constant temperature. The circuitry determines a measurement of the frozen liquid based on maintaining the first sensor and the second sensor at the substantially constant temperature. In some examples, multiple sensor systems can be used in combination to improve the accuracy of the measurement.

Abstract: The embodiments of the invention are directed to a new apparatus and method of measuring the water content using time domain reflectometry (TDR), or electrical conductivity in deep soil levels. to. The method uses flat, flexible, waveguides attached to a flexible sleeve filled with a filling material which press the flexible waveguides against an irregularly shaped interior borehole wall.

Abstract: An apparatus for measuring soil stability of a test surface comprising a housing defining an interior chamber, the housing having an open bottom wherein the housing is configured to be placed over the test surface proximate the open bottom. A means for generating wind shear disposed in the interior chamber, the wind shear generating means configured to generate wind shear proximate the test surface and at least one particle monitor in communication with the interior chamber.

Abstract: The embodiments of the invention are directed to a new apparatus and method of measuring the water content using time domain reflectometry (TDR), or electrical conductivity in deep soil levels to. The method uses flat, flexible, waveguides attached to a flexible sleeve filled with a filling material which press the flexible waveguides against an irregularly shaped interior borehole wall.

Abstract: A photoacoustic sensor that measures carbon black particles emitted in the exhaust gas of a vehicle traveling on a road or being tested on a dynamometer or engine stand. The sensor includes an acoustic waveguide and a pump mounted to an outlet of the waveguide. The pump pulls the gas through the waveguide. A critical orifice is mounted between the pump and the outlet. The critical orifice prevents noise generated by the pump from entering the waveguide. Optical windows are mounted at opposite ends of the waveguide. A modulated source of light is located adjacent one of the windows and irradiates the waveguide. A microphone is attached to the waveguide. The microphone detects an acoustic signal generated by absorption of the light by the particles in the gas. The acoustic signal is proportional to the mass concentration of particles in the gas. The microphone generates an electrical signal proportional to the acoustic signal.

Abstract: An apparatus for measuring particles in an exhaust gas of a vehicle. A transmitter is adapted to provide a source of ultraviolet radiation. The radiation travels through the gas and impinges upon the particles in the gas generating a backscattered radiation. The transmitter also generates a timing signal. A receiver is located in proximity of the transmitter. The receiver is adapted to receive the backscattered radiation and to generate a backscattered signal indicative of the quantity of particles entrained in the gas. A data system is connected to the receiver, the data system is adapted to receive the timing signal and the backscattered signal as an input and to calculate a quantity of particles in the gas at a location from the transmitter.

Abstract: A winter precipitation measuring system for quantifying the precipitation rate of winter precipitation at a given point on the Earth's surface. The winter precipitation measuring system includes an elongated tube, a thermal plate within the elongated tube, and a method and apparatus for maintaining the thermal plate at a substantially constant temperature relative to a reference plate and for determining a precipitation rate in response to the difference in power consumption required to maintain the thermal plate at a substantially constant temperature.