Research Of Time-To-Count Radiometer Based On ARM

With the rapid development of semiconductor technology and the improvement of the chip design level,the capability of ARM Microprocessor has been improved greatly,while its marked prices fall much than before.Embedded systems have been widely penetrated into various fields from scientific research to daily life due for their unique advantages.This article mainly concern about the research of Time-To-Count method with ARM7 LPC2132 microprocessor and G-M detector.ARM structure is based on the reduced instruction set computer(RISC)principle,its instruction set and related decoding mechanism much simpler than complex instruction set computer. Use a small,low-cost ARM microprocessor can achieve very high Instruction throughput and real-time interrupt response.Based on the ARM7TDMI-S nuclear, LPC2132 microprocessors frequency can reach 60MHz.This frequency for Time-To-Count technology is very favorable.By using the timing/counter-pin capture function in LPC2132 microprocessor,the numbers in TC register can be read directly,it is meant we no longer need to call interrupt functions,thus greatly reduce the time the software impurities.This paper is based on my brother Lu Jun' research "Preliminary Research of Time-To-Count measurement method" which is based on MCS-51 system,I have developed the Time-To-Count radiation measurement system greatly by using the high-speed ARM microprocessor.I demonstrate further that High-speed ARM microprocessor chip can greatly improve the measurement range of the G-M detectors with accuracy.At first,this paper will discuss the G-M detector which was used in conventional, and then point out the limits contrast with the G-M detector which was used in Time-To-Count way.I will explain the theory of Time-To-Count,and the feasibility of the Time-To-Count theory used in radiation measurement.Then I will talk about the Time-To-Count radiometer which is based on ARM7 LPC2132 microprocessor,the design of interface circuit of the Time-To-Count radiometer.As the result,I have got the more expanse measurement range and more precision than my big brother's Time-To-Count radiometer which base on MSC-51 SCM.The range of radiometer based on ARM can detect theγray form 20μR/h to 1R/h contrast with before whose range of detection only can be form20μR/h to 30mR/h,and all of the numbers as the results from the experiment have a good linearity Therefore,how we can reduce the impurity time in radiation measurement and how we can precise measure time before count start are the most factors for the capability of radiometer.Experiment with three different models of J33 G-M detectors respectively,as a counter detection devices,in 100μR/h to 1R/h in the radiation field to test.Measuring each measuring five points from the average,with the exposure that the rate of increased radiation measurements of the error between the real value also will be increased.If the measurement error in the 10 percent limit to the extent,this range of equipment for 20μR/h to 1R/h,range span of nearly six orders of magnitude.If the J33 G-M detector was used to the conventional pulse measurement,the range is about 50μR/h to 5000μR/h,fully embodies the use of Time-To-Count method of measuring radiation to the superiority of strength,but also from another angle with the response counting the time before gradually decreasing,impurities in the proportion of time in which more and more,the impact on the measurement results will become more and more serious,as far as possible,the reduction of impurities in time Time-To-Count method of measuring radiation measurement in particular high-intensity Radiation is the key.I used oscilloscope radiation detection equipment this time around impurities 6.5μS,so in calculating the value of the timer when the impurities in less time,before the count can increase the precision of the time.Through experiments that,in the K-value equipment calibration,the exposure rate should be lower down the conditions and measured the time before the exact count is required in a higher rate of exposure under the conditions through the calibration equipment to test.This is because the exposure rate is low,counting the time before the larger impurities time on the measurement results of the impact was not obvious,data lines slope more stable, suitable for the calibration factor determining K-value,and in the exposure rate is higher,Counting time before the small hours of impurities greater impact on the results of the survey,it is clear the online reflected in the data,which can be a very good response to the performance of equipment and range.Results show that the Time-To-Count measurement methods have the most crucial aspect is how to count the time before an accurate measurement.After the large number of experimental data analysis,by counting the time before the time of impurities in impurities can be divided into hardware and software impurities time to time,and time-based software impurities,through the optimization of procedures reasonable,software impurities time to improve the procedures adopted Reduce,oreven math can be used to offset the compensation method,which can be more precise count before time,to be more accurate radiation intensity.For the radiation device, the user can select a different mode of operation to be measured,when the weak radiation,usually measured by the required number of ways,in the radiation field stronger,we should choose the timing measurement methods.Because,when the radiation field weaker,if measured by the required number of ways,will waste a lot of time to collect enough pulse.When the radiation field stronger,because a lot of radiation particles,have a pulse on the high frequency,the required number of measurements will increase the measurement errors,was elected by regular measurement of the way,due to the relatively longer time,so records on the number of particles The relative increase,thereby improving the measurement precision instruments.The research paper by domestic and foreign advanced nuclear radiation measurement instruments of development the status quo,that the current total as of nuclear radiation measurement technology-Time-To-Count theory and its application. The article first demonstration of the principle of the theory of new technologies,and then based on this principle,the combination of high-speed processors ARM7 LPC2132,the G-M detector to detect components for the Time-To-Count radiation meter design.Papers to the experimental method proves Time-To-Count nuclear radiation measurement principles of the scientific method,the radiation for the range and accuracy than the previous pulse to count based on the theory of MCS-51 nuclear radiation meter.The instrument has a wide range,high precision,easy to operate, user-friendly advantages.Users can regularly on the calibration equipment,electronic components to reduce because of the aging equipment on the low impact of the performance parameters,through Time-To-Count the measurement method used,can greatly broaden the range of G-M detector.On the equipment used in the J33 G-M detector,G-M detectors reference linear range of about 50μR/h to 5000μR/h,With the Time-To-Count measurement methods,combining high-speed microprocessors ARM7 LPC2132 the range of Time-To-Count radiometer is 20μR/h to 1R/h.The error allowed within the framework of the nuclear radiation-range than ever before based on the MCS-51 radiation-raising by nearly 200 times,and accuracy than the traditional method to count the pulse,measuring the results of the linear level is better than traditional method.The life of G-M detector was greatly extended.To sum up, this paper has achieved the following results.In this paper,at home and abroad Time-To-Count method of analysis of the status quo,that the Time-To-Count the basic principles of measurement methods,and Time-To-Count the ways theory analysis,derived by counting the time before and the two Adjacent radiation particles time interval,the relationship between mathematics from the perspective of the demonstration Time-To-Count the scientific method.The article described in detail based on the ARM 7 LPC2132 Time-To-Count radiation meter hardware design, software programming process,through high-speed microprocessor LPC2132 use, based on the successful completion of the MCS-51 SCM Time-To-Count meter improvements.To improve the wide range of radiation machines,high precision,easy to operate,user-friendly features.According to the paper summarized the results Time-To-Count technology in a few key factors,such as:the frequency of the processor,counting the time before,impurity time,the number of sampling and measurement of time,The article focus on the composition of the impurity time and the reasons why introduction impurity time,the article has a study guide for domestic nuclear radiation measuring research.