锆及锆合金中的氢含量是影响材料性能的关键因素,通过对助熔剂、称样量、分析功率、脱气功率以及仪器校准实验的探讨,建立了锆及锆合金中痕量氢的测定方法。实验使用LECO NH836氮氢分析仪进行分析,在实验过程中,采用气体分析专用石墨套...锆及锆合金中的氢含量是影响材料性能的关键因素,通过对助熔剂、称样量、分析功率、脱气功率以及仪器校准实验的探讨,建立了锆及锆合金中痕量氢的测定方法。实验使用LECO NH836氮氢分析仪进行分析,在实验过程中,采用气体分析专用石墨套坩埚,并加入0.10~0.20 g分析纯锡粒作为助熔剂。实验优化参数如下:称取0.10~0.20 g的试样、分析功率4000 W、积分时间60 s、脱气功率4500 W。经空白实验计算方法测定下限0.0000356%。根据实验方法对锆合金样品进行分析,氢含量测定结果相对标准偏差(RSD)为7.31%,进行加标回收实验回收率为95%~105%。*第一作者。#通讯作者。Hydrogen content in zirconium and zirconium alloys is a key factor affecting the material properties. A method for the determination of trace hydrogen in zirconium and zirconium alloys was established by exploring flux, weighing volume, analytical power, degassing power and instrument calibration experiments. The experiments were carried out using LECO NH836 nitrogen-hydrogen analyzer, in which a special graphite jacket crucible for gas analysis was used and 0.10~0.20 g of analytically pure tin grains were added as flux. The optimized parameters were as follows: weighing 0.10~0.20 g of specimen, analytical power of 4000 W, integration time of 60 s, degassing power of 4500 W. The lower limit of method determination was calculated as 0.0000356% after blank experiment. The zirconium alloy samples were analyzed according to the experimental method, and the relative standard deviation (RSD) of the hydrogen content was 7.31%, and the recoveries were 95%~105% in the spiked recovery experiments.展开更多
In the infrared spectrum absorbed type gas concentration sensor,voltage signal obtained from the two-channel thermopile infrared detector TPS2534 is very weak.In order to solve this problem,the authors have establishe...In the infrared spectrum absorbed type gas concentration sensor,voltage signal obtained from the two-channel thermopile infrared detector TPS2534 is very weak.In order to solve this problem,the authors have established the structure of the sensor and designed weak signal detecting circuit of the sensor based on infrared spectrum absorption principle,differential de-noising principle and weak signal detecting principle.The authors have made experiments using CH4 gas.The results show that the circuit can remove noise effectively and detect weak electrical signal obtained from the detector.展开更多
Considering that the noises resulting from low modulation frequency are serious and cannot be totally eliminated by the classic filters,a novel infrared(IR) gas concentration detection system based on the least square...Considering that the noises resulting from low modulation frequency are serious and cannot be totally eliminated by the classic filters,a novel infrared(IR) gas concentration detection system based on the least square fast transverse filtering(LS-FTF) self-adaptive modern filter structure is proposed.The principle,procedure and simulation on the LS-FTF algorithm are described.The system schematic diagram and key techniques are discussed.The procedures for the ARM7 processor,including LS-FTF and main program,are demonstrated.Comparisons between the experimental results of the detection system using the LS-FTF algorithm and those of the system without using this algorithm are performed.By using the LS-FTF algorithm,the maximum detection error is decreased from 14.3 to 5.4,and also the detection stability increases as the variation range of the relative error becomes much smaller.The proposed LS-FTF self-adaptive denoising method can be of practical value for mid-IR gas detection,especially for weak signal detection.展开更多
文摘锆及锆合金中的氢含量是影响材料性能的关键因素,通过对助熔剂、称样量、分析功率、脱气功率以及仪器校准实验的探讨,建立了锆及锆合金中痕量氢的测定方法。实验使用LECO NH836氮氢分析仪进行分析,在实验过程中,采用气体分析专用石墨套坩埚,并加入0.10~0.20 g分析纯锡粒作为助熔剂。实验优化参数如下:称取0.10~0.20 g的试样、分析功率4000 W、积分时间60 s、脱气功率4500 W。经空白实验计算方法测定下限0.0000356%。根据实验方法对锆合金样品进行分析,氢含量测定结果相对标准偏差(RSD)为7.31%,进行加标回收实验回收率为95%~105%。*第一作者。#通讯作者。Hydrogen content in zirconium and zirconium alloys is a key factor affecting the material properties. A method for the determination of trace hydrogen in zirconium and zirconium alloys was established by exploring flux, weighing volume, analytical power, degassing power and instrument calibration experiments. The experiments were carried out using LECO NH836 nitrogen-hydrogen analyzer, in which a special graphite jacket crucible for gas analysis was used and 0.10~0.20 g of analytically pure tin grains were added as flux. The optimized parameters were as follows: weighing 0.10~0.20 g of specimen, analytical power of 4000 W, integration time of 60 s, degassing power of 4500 W. The lower limit of method determination was calculated as 0.0000356% after blank experiment. The zirconium alloy samples were analyzed according to the experimental method, and the relative standard deviation (RSD) of the hydrogen content was 7.31%, and the recoveries were 95%~105% in the spiked recovery experiments.
文摘In the infrared spectrum absorbed type gas concentration sensor,voltage signal obtained from the two-channel thermopile infrared detector TPS2534 is very weak.In order to solve this problem,the authors have established the structure of the sensor and designed weak signal detecting circuit of the sensor based on infrared spectrum absorption principle,differential de-noising principle and weak signal detecting principle.The authors have made experiments using CH4 gas.The results show that the circuit can remove noise effectively and detect weak electrical signal obtained from the detector.
基金supported by the National "863" Project of China (Nos. 2007AA06Z112,2007AA03Z446 and 2009AA03Z442)the National Natural Science Foundation of China (No.61077074)the Science and Technology Department of Jilin Province of China (Nos. 20070709 and 20090422)
文摘Considering that the noises resulting from low modulation frequency are serious and cannot be totally eliminated by the classic filters,a novel infrared(IR) gas concentration detection system based on the least square fast transverse filtering(LS-FTF) self-adaptive modern filter structure is proposed.The principle,procedure and simulation on the LS-FTF algorithm are described.The system schematic diagram and key techniques are discussed.The procedures for the ARM7 processor,including LS-FTF and main program,are demonstrated.Comparisons between the experimental results of the detection system using the LS-FTF algorithm and those of the system without using this algorithm are performed.By using the LS-FTF algorithm,the maximum detection error is decreased from 14.3 to 5.4,and also the detection stability increases as the variation range of the relative error becomes much smaller.The proposed LS-FTF self-adaptive denoising method can be of practical value for mid-IR gas detection,especially for weak signal detection.
