Abstract: A measuring apparatus for a concrete structure includes an eddy current sensor configured to contact the concrete structure; a ground penetrating radar (GPR) sensor configured to contact the concrete structure; at least one memory storing one or more instructions; and a controller operably connected to the eddy current sensor, the GPR sensor, and the at least one memory, wherein the one or more instructions, when executed by the controller, cause the apparatus to: provide a first input signal to the eddy current sensor and a second input signal to the GPR sensor, obtain a first moisture content of a portion of the concrete structure based on an output of the eddy current sensor, obtain a second moisture content of the portion of the concrete structure based on an output of the GPR sensor, and obtain a final moisture content of the portion of the concrete structure based on at least one of the first moisture content and the second moisture content.

Abstract: A damper for an exhaust duct of an exhaust line of a semiconductor fabrication apparatus includes a damper body to be inserted into a fixing hole in the exhaust duct in a first direction, the damper body having a diameter substantially the same as a diameter of the fixing hole, and plural push buckles. The push buckles are provided on a distal end of the damper body along an outer circumferential surface of the damper body and spaced apart from each other around a circumference of the damper body, the push buckles being resilient and movable with respect to the outer circumferential surface along a second direction perpendicular to the first direction. When the push buckles have passed through the fixing hole in the first direction, the push buckles prevent a return movement through the fixing hole in a direction opposite to the first direction.

Abstract: A strain measuring device includes a first sensing optical fiber disposed on a surface of a measurement target. A second sensing optical fiber is spaced apart from the first sensing optical fiber and arranged parallel to the first sensing optical fiber. The second sensing optical fiber is spaced apart from the surface of the measurement target. An optical fiber guide has an inner cavity. The optical fiber guide is bonded to the surface of the measurement target to be positioned on the surface of the measurement target. The second sensing optical fiber is disposed in the inner cavity. A controller receives measured values from the first sensing optical fiber and the second sensing optical fiber. The first sensing optical fiber and the second sensing optical fiber include optical fibers for measuring strain.

Abstract: A damper for an exhaust duct of an exhaust line of a semiconductor fabrication apparatus includes a damper body to be inserted into a fixing hole in the exhaust duct in a first direction, the damper body having a diameter substantially the same as a diameter of the fixing hole, and plural push buckles. The push buckles are provided on a distal end of the damper body along an outer circumferential surface of the damper body and spaced apart from each other around a circumference of the damper body, the push buckles being resilient and movable with respect to the outer circumferential surface along a second direction perpendicular to the first direction. When the push buckles have passed through the fixing hole in the first direction, the push buckles prevent a return movement through the fixing hole in a direction opposite to the first direction.