The Development Of Digital γ Spectrometer Based On PDA And Bluetooth

Fieldγ-ray spectrometry is using the portableγspectrometer int the filed directly to measure the content of U, Th, K in the rocks'surface, soil, ore. And obtaining the information of relevant nuclide. It is widely applied to geological mapping, radioactive minerals and non-radioactive mineral exploration, hydrogeology and engineering geology exploration, the monitoring of construction materials and environmental and so on.Since theγspectrometer needs to collect the signal of filed spectrum and process the measuring data, the demand to the apparatus'portable, practical, operational applications is highly. The previous portableγspectrometer is highly power consumption, slowly data processing speed, and only through cable can the host be communicated with the probe, operational hardly. To these question, the author developed a digitalγspectrometer base on PDA and Bluetooth: using PDA as the host to acquire and process the measuring data, and the probe is designed to a digital one-body, the detector, amplifier, embedded Bluetooth module and multi-channel analyzer are integrated together in the probe, it communicate with PDA via Bluetooth. In the PDA base Windows Mobile system using embedded Visual C++ language to developγspectrometer application software, realize wireless communication with the probe, complete the corresponding spectral data analysis and processing, and GPS functionality.This paper derived from the "863 Program" Major research project—"the research of aerialγ-ray spectrum exploration systems", is to provide a portable, fast, intelligentγspectrometer equipment for carrying out method experiments of the aerialγ-ray spectrum measurement on the ground. On the basis of work of the predecessors, this paper made some improvements to the traditional portable multi-channelγspectrometer and the achievements and innovation of the paper are as follows:1. The Bluetooth low-power technology is applied to spectrometer, realizing wireless transmission, can effectively avoid the cable failure of the traditional spectrometer;2. It's the first time for domestic spectrometer to achieve the real-time GPS geographic information collection records;3. Using intelligent stable spectrum, can effectively inhibit the spectrum of the impact of drift;4. Greatly enhance the spectrometer's capability of the data processing and speed, and also greatly increased the equipment's portability and operability; 5. The Apparatus is low-power consumption, the battery can work continuously 25 hours;6. Compared with similarγspectrum application software, the software discussed in the paper is characterized by the following achievements:1) Using sliding discrete convolution transform function to smooth spectrum,the effect of spectrum smoothing is better;2) Using 512 channel for spectrum analysis, is effectively to reduce the spectrum of the statistical fluctuation, the effect of spectrum analysis is better;3) For different proportion of the content of U, Th, K, using three kinds of energy calibration models, ensuring the accuracy of data analysis;4) Support the function of nuclide identification, it is convenient for user to detection the radioactive sources;5) Real-timely storage measurement data in the 2G memory card;6) The user interface based on windows mobile system, support for touch screen operation, greatly facilitate users of equipment and analysis of spectrum data.For some nuclear measurement field, sometimes the presence of electromagnetic interference, strong radiation and high-level radioactive and etc., with Bluetooth technology, user can remotely control the apparatus through PDA, so as to avoid radioactive radiation to the human body and inhalation of internal exposure on site measurement, this madeγspectrometer based on PDA and Bluetooth to have good practical value and application prospect.Through testing and actual using, the weight of theγspectrometer based on PDA and Bluetooth <2.7kg, power consumption <1.4W, the energy resolution is less than 8.6% (@0.661MeV 137Cs), the analytical error of U, Th, K are K<5%, U<7%, Th<5%, and the drift of characteristic peak≦±1 channel. The performance of apparatus is stable and reliable, easily operation, accurate measurement, and it can be applied to all kinds of substances'measurement ofγspectrum indoor or in the field. And the apparatus has been small-scale produced and popularized and applied.