Accuracy analysis of iron content of galvanized coating using an X-ray fluorescence spectrometer with an L-spectrum

The accuracy(repeatability and reproducibility) of the iron content analysis of galvanized coating using an X-ray fluorescence spectrometer with an L-spectrum is not better than that of flame atomic absorption spectrometry, sometimes it exceeds the quality control limit.Influences, such as current, voltage, equipment(internal circulating water, 10%CH4+90%Ar, and vacuum) checking, instrument monitoring, sample cleaning, and oper-ators, were investigated by means of 6-sigma and lean operations to improve accuracy.

Potential Applications of X-ray Fluorescence Core Scanner in Elemental Analyses of the Muddy Sediments on the Coastal Shelves of China and in Ecological Study

Large areas of muddy sediments on the coastal shelves of China provide important samples for studying climate and ecological changes. Analysis of a large number of such samples, which is essential for systematic study on environmental information recorded in mud areas because of complicated sedimentary environment and variable sedimentary rate, requires a fast and economical method. In this study, we investigated the potential of X-ray fluorescence core scanner （XRFS）, a fast analytical instrument for measuring the elemental concentrations of muddy sediments, and observed a significant correlation between the element concentrations of muddy sediments determined by regular X-ray fluorescence spectrometer （XRF） and XRFS, respectively. The correlations are mainly determined by excitation energy of elements, but also influenced by solubility of element ions. Furthermore, we found a striking link between A1 concentrations and marine-originated organic carbon （MOC）, a proxy of marine primary productivity. This indicates that MOC is partly controlled by sedimentary characteristics. Therefore, XRFS method has a good potential in fast analysis of a large number of muddy sediment samples, and it can also be used to calibrate MOC in ecological study of coastal seas.

Application of a Portable XRF Spectrometer for <i>In-Situ</i>and Nondestructive Investigation of Pigments in Two 15th Century Icons

A simple portable X-Ray Fluorescence (XRF) spectrometer was successfully used for in-situ and nondestructive identification of the painting materials in two 15th century icons from the Onufri Museum in Beart, Albania. The spectrometer is based on a low power X-ray tube, a thermoelectrically cooled Si PIN detector and the spectrum acquisition system. It was assembled and adjusted at our laboratory for the investigation of the icons. A small number of pigments were clearly identified by X-Ray Fluorescence (XRF) measurements in both icons. This includes Lead white for the white color, gold and yellow ochre for the yellow color, red lead, cinnabar and red ochre for the red color, as well as cooper based pigments for the green color. At the same time, the investigation raised some new questions that need further investigations by the use of additional analytical techniques. The results show that in both icons are used similar pigments, which are in accordance with the Byzantine icon painting tradition.

手持式X射线荧光光谱仪测定进口矿产品中有害元素

为在云南边境口岸充分应用快速检测技术,利用手持式X射线荧光光谱仪(XRF)对标准样品及进口矿产品进行了定性、半定量测定,确定了矿产品中各种元素成分及其含量,与标准样品认证值以及实验室化学分析法测定结果相比较,验证了手持XRF对矿产品中元素分析的准确性。结果显示,手持XRF仪测定10种标准样品含量与认定值相符;检测不同矿区进口矿石中化学元素的含量可初步识别矿石种类;测定铁矿中As元素含量,有80%样品检测结果在重复性要求的允许范围内,与化学法结果相近。能够对多种类矿产品进行快速识别和品质评价,并对海关进口矿产品口岸监管的快速查验工作发挥有效作用。

手持式X射线荧光光谱仪用于现场合金牌号鉴别的误差控制探讨

手持式X射线荧光光谱仪可用于金属加工、使用、回收等各领域材料牌号鉴别,因此成为现场材料管理的有效手段。但当对材料中Mn、Ti、V等合金成分不大于0.5%的牌号鉴别时,却得不到准确的牌号信息,给现场检测人员带来了极大的困扰。为控制现场鉴别误差,实验将手持式X射线荧光光谱仪鉴别条件优化为电压25kV,检测时间25s,样品检测面积20mm×20mm,表面粗糙度Ra6.3,5m内无强磁干扰的实验条件;对6组含Cr、Ni、Mo、Mn、Ti、V的合金样品进行检测和记录,发现Mn、Ti、V检测结果与标准规定值之间存在较大偏差,而Cr、Ni、Mo结果在标准范围内,数据稳定;因此实验选取Cr、Ni、Mo为指标元素,将指标元素检测结果作为牌号鉴别依据,确定牌号正确与否。对两节未知牌号的合金钢管,采用手持式XRF进行牌号鉴别,同时与电感耦合等离子体原子发射光谱(ICP-AES)的Cr、Ni、Mo测定值进行对照,现场检测结果与ICP-AES的结果吻合较好,完全能满足合金牌号鉴别的需要。

手持式X-射线荧光光谱仪在金属材料检测中的应用

系统评述手持式X-射线荧光光谱仪的发展过程,详细比较、分析其辐射情况,探讨金属材料状态对检测的影响。综合基本参数法、自动选择模式测试金属材料的数据,提取检测结果,与认定值或其他方法的分析结果基本吻合。

Proximal sensor-enhanced soil mapping in complex soil-landscape areas of Brazil

Portable X-ray fluorescence(pXRF) spectrometry and magnetic susceptibility(MS) via magnetometer have been increasingly used with terrain variables for digital soil mapping. However, this methodology is still emerging in many countries with tropical soils. The objective of this study was to use proximal soil sensor data associated with terrain variables at varying spatial resolutions to predict soil classes using the Random Forest(RF) algorithm. The study was conducted on a 316-ha area featuring highly variable soil classes and complex soil-landscape relationships in Minas Gerais State, Brazil. The overall accuracy and Kappa index were evaluated using soils that were classified at 118 sites, with 90 being used for modeling and 28 for validation. Digital elevation models(DEMs) were created at 5-, 10-, 20-, and 30-m resolutions using contour lines from two sources. The resulting DEMs were processed to generate 12 terrain variables. Total Fe, Ti, and SiO_(2) contents were obtained using pXRF, with MS determined via a magnetometer. Soil class prediction was performed using the RF algorithm. The quality of the soil maps improved when using only the five most important covariates and combining proximal sensor data with terrain variables at different spatial resolutions. The finest spatial resolution did not always provide the most accurate maps. The high soil complexity in the area prevented highly accurate predictions. The most important variables influencing the soil mapping were MS, Fe, and Ti. Proximal sensor data associated with terrain information were successfully used to map Brazilian soils at variable spatial resolutions.