Abstract: A structural displacement sensor that includes an arched member having two ends, where each end is attached to a fastening member. In an embodiment of the invention, the fastening members are configured to be attached to a structure. Further, a strain gauge is attached to the arched member, and the strain gauge is operatively connected to a signal processing device. In an embodiment, the arched member and strain gauge are configured to measure a displacement of the structure based on the amount of strain detected on the strain gauge.

Abstract: A scour sensor and method of detecting scour in the bed of a body of water as well as a sensor and method for determining the subgrade modulus of a subgrade are provided. The scour sensor includes an elongated rod that can be driven into the bed of a body of water such that a portion of the rod is cantilevered from the bed into the water. The rod has a known dynamic characteristic that is variable depending on the amount of the rod that is embedded in the subgrade. In one implementation, the known characteristic is the natural frequency of the rod. The scour sensor further includes a sensor element for monitoring a dynamic characteristic of the rod. Methods of using and calibrating a scour sensor are also provided. Further, the sensor may be used to determine a subgrade modulus of the subgrade.

Abstract: A structural displacement sensor that includes an arched member having two ends, where each end is attached to a fastening member. In an embodiment of the invention, the fastening members are configured to be attached to a structure. Further, a strain gauge is attached to the arched member, and the strain gauge is operatively connected to a signal processing device. In an embodiment, the arched member and strain gauge are configured to measure a displacement of the structure based on the amount of strain detected on the strain gauge.

Abstract: A scour sensor and method of detecting scour in the bed of a body of water as well as a sensor and method for determining the subgrade modulus of a subgrade are provided. The scour sensor includes an elongated rod that can be driven into the bed of a body of water such that a portion of the rod is cantilevered from the bed into the water. The rod has a known dynamic characteristic that is variable depending on the amount of the rod that is embedded in the subgrade. In one implementation, the known characteristic is the natural frequency of the rod. The scour sensor further includes a sensor element for monitoring a dynamic characteristic of the rod. Methods of using and calibrating a scour sensor are also provided. Further, the sensor may be used to determine a subgrade modulus of the subgrade.

Abstract: A device for measuring entrained air in concrete, includes a needle tube for insertion into the concrete, the needle tube having a distal end; an optical fiber extending through the needle tube to the distal end, with the end of the optical fiber and the distal end of the needle tube being ground to have a sharp conical angle; a laser diode which produces laser light; a coupling device which supplied the laser light from the laser diode to the optical fiber and which separates the light reflected back through the optical fiber; and a photodetector which converts the received light from the coupling device to an electrical signal corresponding to the intensity of the reflected light.