3results about How to "Avoid chirping" patented technology

The utility model discloses a crack sensing sensor based on optical fiber sensing, and belongs to the technical field of civil structure health monitoring. The problems that the testing precision of an existing crack measuring device is extremely prone to being interfered by the surrounding environment, and the measuring precision is low are solved. The optical fiber grating sensor comprises a mounting shell, a cantilever beam and an optical fiber grating, the mounting shell is of a cavity structure with a fixed connecting end and a stretching movable end, and the fixed connecting end and the stretching movable end can slide relatively; the cantilever beam is of a long-strip-shaped structure with elastic deformation and resilience capacity, the cantilever beam is horizontally arranged in a cavity of the installation shell, the length direction of the cantilever beam is the same as the moving direction of the stretching movable end, the tip end of the cantilever beam is fixedly connected to the fixed connecting end, and the tail end of the cantilever beam abuts against the stretching movable end and is in a bent state. The fiber bragg grating is installed on the cantilever beam, and the length direction of the fiber bragg grating is consistent with the length direction of the cantilever beam. The device is mainly used for measuring cracks in the road surface and the roadbed.

The invention relates to the technical field of optical fiber sensing, in particular to a fiber bragg grating low-temperature sensor and a preparation method and a monitoring method thereof, and the fiber bragg grating low-temperature sensor makes use of the characteristics that a polyether-ether-ketone material is large in thermal expansion coefficient and has good adaptability in a frozen soil environment, so that the sensitivity enhancement effect of the packaged sensor is obvious; the device can well resist frozen soil freezing and thawing, water erosion and other influences, realizes long-term stable and high-precision temperature measurement, and is simple in structure and easy to process; according to the preparation method, the extra pressure stress acting on the fiber bragg grating in the cooling process after the thermosetting adhesive is heated and cured is counteracted through enough tensile stress, the chirp phenomenon caused by full-pasting packaging can be effectively avoided, good thermal coupling between the substrate and the fiber bragg grating is achieved, the use reliability is improved, and the service life is prolonged; the monitoring method adopts a specific mounting mode to realize good contact between the base and the mounting position, and the base can freely expand and retract under the action of temperature, so that the requirement of high longitudinal resolution of the temperature gradient of the frozen earth stratum is met.

The utility model relates to record player technical field, concretely relates to a black record player and record player suit. Black record player includes: support plate, is provided with record arm subassembly and turntable subassembly on the support plate, bottom plate, the bottom plate sets up in the support plate side away from record arm subassembly, damping component, the damping component includes the first damping module group and the second damping module group that connect each other, the first damping module group is connected with the bottom plate, the second damping module group connects between the support plate with the bottom plate, wherein, the first damping module group is used for and the contact of placing platform. Adopt above -mentioned form, can reduce the influence of vibration to tone quality, promote the experience feeling when playing.