Design Of Detection System For 32 Channel Temperature Field By Acoustic Method

The system shows that the designed system can run normally according to the design idea. Temperature field measurement technique based on acoustic propagation time, to calculate the temperature distribution of the measured area. Built on the primary function of intermediate temperature, the technique gets the advantages of wide temperature measurement range, large measuring range, non-contact and non-interfering with the measured object.Research on grain temperature monitoring as background. In the process of grain storage, when the occurrence of fungi and insect pests, resulting in local temperature rise, we also say that is the hot appear. Because the grain temperature change is postponed, the measurement time is lowly. In the process of acoustic propagation time measurement, allowed a large amount of data acquisition, using time consuming but anti-noise capability of delay estimation algorithm and repeated measurement, to ensure that the measurement data with high signal to noise ratio.At present, the research on the temperature field measurement technology in the domestic acoustic method is generally performed on the two-dimensional level. Nonetheless, in some occasions, such as the temperature of the storage of food monitoring, it is necessary in order to carry out three-dimensional temperature field reconstruction. In order to reflect the larger area, this paper designed a 32 channels aural method of temperature field detection system. The hardware composition and software design of the system is adopted in detail in this paper. The hardware of the system is mainly composed of cabinet PXIe-1082, controller PXIe-8135, data acquisition module PXIe-4461, PXIe-4497, multiplexer switch PXIe-2575 and acoustic transceiver array. The system software is produced by LabVIEW, which controls the hardware modules to collaborate with a view to complete the transmission, reception, data acquisition, data storage and the calculation of the time of acoustic wave propagation.The location of the transceiver and the effective path of the sound wave are a direct result of the reconstruction accuracy of the temperature distribution in the tested area. To this end, this paper makes a simulation study on the acoustic CT reconstruction of three-dimensional temperature field. 30 acoustic transceivers are assigned to two different ways on the periphery of the measured area with / without a transceiver on a regional vertex. Section of the measured area is seen as 1000 and 1500 pixels in two ways. On the model temperature field of about two thousand distinct hot spots, the simulation data are reconstructed. The quality of temperature field reconstruction is assessed by the mean square error, hot spot temperature error and hot spot position error. Reconstruction results show that the layout of the transceiver and the measured area will get to make a greater impact on the quality of the reconstruction. Better reconstruction effect can be achieved by the receiver in the region vertex setting. Choosing appropriate filtering parameters can improve the anti noise ability of the system.The system needs to show that the designed system can run normally according to the design idea.