X-ray Fluorescence Spectral Element Analyzer FAQ – Infx Scientific Instruments
Energy Dispersive X-ray Fluorescence Spectrometer Analysis Q&A
1. What is X-ray fluorescence analysis?
Answer: (1) X ray is a kind of electromagnetic wave, short wavelength than uv, about 0.001 to 10 nm. X-ray irradiationAfter material above, mainly from the material can be observed in the following three kinds of X-ray. Fluorescence X-ray scattering, X-ray, through X-ray, ESI NT products use the fly thoughts are based on the first kind of fluorescence X-ray measurement, obtain the element information from the material (composition and film thickness) fluorescence X-ray method principle. Material by X ray irradiation, occurrence elements inherent in the X ray (inherent X-ray or characteristic X ray). Fluorescence X-ray device is based on the X-ray test and obtain the element information.
(2) the principle that high-energy particles (electrons or continuous X ray, etc.) and the collision of target materials, target atom of inner electrons (such as K,Layer) from become photoelectron, such as L, M, there is a hole, the atoms in the excited state, then the outer powerThe child immediately jump into the lining of the lower energy empty orbit, fill the hole. If at this time in the form of X ray radiation energy excess, is the characteristics of X-ray. When electrons are ejected from the K layer, all outer electrons can jump back to the hole formed K K layer characteristic X ray. By L, M, N. The transition layer to layer K X-ray Ka, respectively, KB, Ky. Radiation. Likewise, from L or M layer will have corresponding L or M characteristic X ray: La, LB.; Ma, MB… Ka, KB the wavelength of the radiation into the characteristics, it depends on K, L, M the energy of the electron energy layer: it can be seen that different elements with atomic structure, all the energy of the shell is different, so their characteristic X-ray wavelength is different. Usually people of X-ray called X-ray tube is the primary X-ray. By primary X-ray excitation light irradiation samples, excited state energy release of the sample is not in the form of radiation for atomic absorption internal subprime X-ray, This is the X ray fluorescence due to various elements to launch with a specific wavelength (or energy) the identity of the X-ray can use lithium and alcohol move different detectors, such as silicon half body and glaze of spectrum analyzer to determine the yuan table for and the intensity of identification line table can be used to do the yuan is reasonable
X-ray Fluorescence Spectral Element Analyzer FAQ – Infx Scientific Instruments
2. What are the advantages and disadvantages of X-ray fluorescence analyzer?
A: The advantages of X-ray fluorescence analyzer
Sensitive (1) sampling methods, such as SEA series is equipped with a large measure, most of the sample can be tested directly. Sampling can reduce the loss, for die casting has good mechanical parts can do NDT, without destroying samples.
(2) the test rate is high, can undertake a large number of sample testing in less time, the analysis results can be output directly by computer networking.
(3) the analysis faster.
(4) for pure metal can be used without the prototype analysis, analysis of accuracy can reach requirements.
(5) don’t need professional laboratory and operating personnel, and does not introduce other substances harmful to the environment
.X-ray fluorescence analyzer of faults:
(1) about non-metallic and boundary between metal and nonmetal elements is accomplished very hard accurate detection. In the measurement by the basic parameter methodTry, if the test sample to contain the elements such as C, H, O, can appear error.
(2) not as arbitration analysis method, cannot as a national certification according to test results, can’t distinguish between the element valence.(3) for alloy steel containing nonmetal elements, such as, representative samples need drawing standard curve, the accuracy of the results of the analysis is based on the prototype based on the analysis of the chemical.(4) standard curve model needs to update from time to time, change in instrument or standard sample changes, standard curve models will also change.
3. Can you tell me the wavelength fluorescence spectrometer and energy scattering model is the difference between fluorescence spectrometer?
Answer: (1) the difference between can come loose and dispersive should first from the nature of the X ray: X ray as a form of electromagnetic wave has obvious wave and grain of two sex. Wave wavelength, frequency, and reflection, refraction, diffraction, interference and other properties, particle has the properties such as quality, speed, the kinetic energy and potential energy. To research and development of two different physical properties of the wavelength of type X fluorescence spectrometer is called scattering wavelength fluorescence spectrometer, the energy X-ray fluorescence spectrometer is called scattering type fluorescence spectrometer.
(2) wavelength dispersive X-ray fluorescence spectrum, like the atomic emission \ absorption spectrometer, is the need to separate the dispersion optical systemTo distinguish different secondary fluorescence spectrum characteristic X-ray excitation, and then by the radiation detector (such as proportional counter \ semiconductorsDetection detector, etc.); Type and energy dispersive X-ray fluorescence spectrometer is not like the former need to separate the dispersion system, its secondary fluorescenceSpectral dispersion and detection are made by radiation detector according to its different energy detection and it is put in the computer or single chip microcomputer.
(3) wave scattering type of fluorescence spectrum technology is relatively mature, but because of complex structure, high prices, limited application, energy dispersionShoot type X fluorescence spectrometer structure is simple, the price is low, and because the detector technology in recent years, the increasing maturity of the performance of the spectrometer is becoming more and more close to the spectrometer. Anyway, instrument is not perfect, the most suitable is the best.
(4) the detection range of elements, wavelength is Be ~ U, and energy model is usually Na ~ U (vacuum), or Al ~ U
(5) the wavelength of more types of software, can be used in all walks of life
X-ray Fluorescence Spectral Element Analyzer FAQ – Infx Scientific Instruments
4. Use the EDXRF lead cadmium test samples in mercury bromide chromium, which elements between interference? How to remove?
A: (1) It should be clearly understood that there are many elements that interfere with fluorescence analysis, and each element to be tested will be affected by some other element. For example, arsenic interference often occurs in the process of lead analysis, and germanium and rhenium interference often occur in the process of mercury analysis.
(2) Common interference (experience)Cd: Br/Pb/Sn/someone Pb: Br/Hg: Br/Pb/Fe/Ca Cr: Cl Br: / Fe/Pb
(3) and at the same time more than two characteristic line measurement analysis. Such as Pb, it is necessary to select PbLa and PbLb test and determine the two spectral lines. In general, if Pb really up to the test results, then according to the characteristic curve of the two values should be close to, also on the reproduction chart displays the wave at the same time, if the two line one no wave or two peaks, then obviously the result of test is caused by the interference of other elements of miscalculation. If PbLa and PbLb test results of the two lines are too big, so big that curve is interference by other elements. Select test results with numerical shall prevail. Other elements can also be based on the same method. This method can be a certain degree to remove the interference between elements.
(4) in addition, the effects of coexisting elements, in ESI the fly instrument includes qualitative analysis in software menu, such as to determine the test samples containing what elements, you can use the following methods. Use Pb for example, because of the characteristics of PbLa peak interference is AsKa is larger, the Br, Bi has a small amount of overlap, and PbLb FeKa, interference of SeKb peak is bigger, and Br, Bi overlap, so if you are a test of plastic, the sample may contain Br (is possible), then we can’t use PbLb data as test results, and the need to use PbLa test data as the test results, because PbLa less affected by Br, test data is accurate. If use PbLb, data is usually large at the moment. Other elements may also be in accordance with this processing.
5. I analyze a AC line plug in the company. Use block FP method, found: Cu 55.50% zinc
33.73% Ni 9.02% Pb 0.85% Mn 0.82% Y 0.08%. Lead to measure the controlled substance, and a small amount of Y, could you tell me what is the reason, don’t know how inside the ROHS regulations. This kind of plug can contain lead, can what percentage.
Answer: (1) the ESI the fly, instrument analysis pure metal block, FP method can be used without the prototype, fully automatic, fast accurate. Copper alloy in the content of Pb in the RoHS requirement is 40000 parts per million, the plug can be up to standard. 1
(2) the brass plug lead normal, leaded brass increases can be cut, for process are common, so there is a 40000 exemption limit in ROSH.
(3) the power cord plug outer may have plating, base material is copper alloy, if separate test matrix, the data should be around 3 ~ 4 w,Just within the scope of the copper alloy saving data, and mixed together, so data can be reduced, with a physical quantity line method test of copper alloy is correct.
(4) Y (yttrium) is a rare earth element, does not generally exist in the common metal block, may be interference.
X-ray Fluorescence Spectral Element Analyzer FAQ – Infx Scientific Instruments
6. The metal coating and how PCB using XRF testing?
A: (1) To distinguish the object of concern, the two most common categories of fluorescence analyzer are film thickness analyzer and element analyzer, which are targeted atThe target is different. For example, the thickness can be measured by thin film FP method or thin film measurement line method, and the element is measured by block FP method and block physical measurement line method.
(2) To measure the thickness of the coating, it is best to buy a standard sheet file for accuracy. If you need to control harmful substances in PCB, you can powderMixed test after crushing, you can also buy an instrument with a surface scanning function, and then determine which point may have a problem after scanning, and finally determine
7. Cr levels in leather X fluorescence analysis, chemical analysis +, Cr6, what the reason is, how to deal with?A: leather tanning often join the chrome tanning agent, can gift for chromium salt into leather soft, plump, high strength, resistant storage, water resistantWash, not easy fade, tanning, damp and hot stability is good wait for a good performance. But Cr6, + is harmful to the human body and natural environment, the need to be controlled.Can Cr6, + content is obtained by X ray fluorescence analysis, by the principle of fluorescence analysis, X ray fluorescence analyzer is based on the different elements of fluorescent X-ray energy is different, the influence of element valence, ordinary analyzer cannot distinguish between valence, the measured Cr for total chromium, contains various valence state, therefore, need to accurate analysis by using chemical methods.
8. X – RAY can penetrate 5 um thick Ni plating? To detect the contents of Pb will detect matrix (fast cutting steel) containing Pb.
Answer: (1) general metal can penetrate through the 0.1 mm, 2 mm plastic can penetrate, different metal penetration, heavy metal penetration ability is poor, so the use of heavy metals such as lead to do radiation protection for Ni5um no problem at all.
(2) plating product outer even multi-layer plating, generally no more than 100 um thickness, X-ray equipment can through basic,So will detect lead in substrate, the test data will contain inside the Pb in the matrix.
(3) because can penetrate, detect the Pb in the base material at the same time, it is recommended to establish procedures when using base material instead of Fe is infiniteThick standard be revised, so the effect will be better.
(4) X – RAY nickel plating thickness measurement, probably to 30-40 um thick, can be correctly determined.
X-ray Fluorescence Spectral Element Analyzer FAQ – Infx Scientific Instruments
9. ED – standard curve of XRF method is what?
Answer: (1) the working curve method is to use standard sample to establish a standard calibration curve and the test measurement results according to this curve to calculate again. Several standard samples with known concentrations of strength, get a series of corresponding signal intensity, intensity and concentration corresponding to form a series of points to synthesize a standard curve by the software, test samples, test instruments to a signal intensity corresponding to the curve, can know the concentration of the corresponding.
(2) the standard working curve method for relative FP method accuracy is higher, but the instrument itself exists background intensity, leading to lower than the background intensity of negative samples, the accuracy of the standard and strength drift curve, the curve of the detection limit and the curve of the ceiling.
10. What the role of the collimator is mainly? And what is its structure? This is a separate parts?
Answer: (1) is the role of collimator diverge rays into parallel beam, is a series of small pieces of metal.
(2) the collimator is composed of parallel plates, the smaller the spacing and the higher the resolution, the less strength also.
(3) fiber collimator is the most basic optical device of optical fiber communication system, its role is the divergent beam into the fiberCollimating light, make its in a very small loss to optical fiber coupling.
(4) the collimator of the well type, also have round, is to restrict the X-ray corresponds to the measuring range of the sample.
11. Recently we use fluorescence analyzer cameras can’t use, can not see the part of the samples, is to open after what also don’t show, don’t know what reason be?
Answer: (1) may be a data interface is loose, can put the computer USB line to dial out to connect again, or view line CCD video card whether is loose.
(2) after completing the above steps, can restart the computer to check again.
(3) there is another possibility, the early USB cable transmission speed slow, such as transmission packet is too large or too quickly could lead to a data block, this time can be upgraded or put sample closed Windows samples again.
X-ray Fluorescence Spectral Element Analyzer FAQ – Infx Scientific Instruments
12. The problem of the uncertainty of EDXRF test?
Answer: (1) fluorescent element analysis is limited by the uniformity of the prototype preparation or difficult to sample, most can only as a quality control method, the accuracy of low relative chemical analysis.Element
(2) analysis of the method is based on the standard substance checking-measuring curve analysis of standard curve, if the actual sample weightAnd standard material not consistent, so certainly not very accurate analysis results, only for your reference.
(3) use the basic method of parameter testing metal, fruit in the test sample contains the lighter elements, such as C, H, 0 can appear error, because the instrument can’t identify these elements.
13. Our instruments models are older, have no manual, instrument need to add liquid nitrogen to cool, don’t know is used for cooling detector or light pipe.
Answer: (1) detector. Detector is a lot of more phyletic, common have direct proportion counter, commonly used in film thickness gauge, is characterized by low resolution, counting and high strength. Si (Li) detector, is characterized by high resolution, but you need to liquid nitrogen cooling. And Si (PIN) detector, electronic cooling, do not need to liquid nitrogen, but the resolution is lower, in addition, our company high-end models with SDD detector, which can realize high count rate, high resolution without liquid nitrogen refrigeration.
(2) the liquid nitrogen in the air will be sublimated, 1 liter, usually use open boot is the same, will increase the cost,Liquid nitrogen and liquid nitrogen temperature to – 196 ℃ skin contact can cause frostbite, such as vaporization under atmospheric pressure nitrogen excess, can make the oxygen partial pressure drops in the air, causing anoxia suffocate
14. Can help explain the F P quantitative analysis method.
Answer: the FP method called the English fundamental parameter method, Chinese meaning is the basic method, is XRFOn the use of a matrix correction method. Basic parameter method is the application of the theory of fluorescence X-ray intensity calculation formula and the original level of X-ray spectrum intensity distribution, mass absorption coefficient, fluorescence yield, absorption edge warp factor and basic physical constants, such as line fraction by complex mathematical operation, convert the measured intensity of a few schools are the content of elements. Based on the basic parameters of a small amount of sample method, the final result also can achieve high accuracy; Don’t even have the prototype can also be calculated. The stand or fall of FP method is to measure an important basis for the performance of instrument.
15. Fluorescence X-ray irradiation area, with the resolution of the matter? Irradiation area increases the resolution will fall?
Answer: (1) the illuminate of fluorescent area is related to the intensity of the measured. Resolution and spectral crystal, collimator, detectors, etcHave a relationship. Irradiation area can switch by collimator.
(2) the resolution is a problem of detector. For ESI the fly of the instrument, the irradiation area increases, the effect is better, for example, adjustable light spot area of X-ray system, the 1 mm spot test effect is far worse than 5 mm test results.
(3) the size of the exposure area directly affects the accuracy of the test results, under the condition of invariable in all test conditions, test area, the greater the intensity of the test is higher, and the resolution has nothing to do, directly affect the resolution only slit (collimator), crystal and detector.
X-ray Fluorescence Spectral Element Analyzer FAQ – Infx Scientific Instruments
16. EDXRF USES the method of the prototype and test repeatability, stability, and have the standards?
Answer: (1) samples from a variety of criteria to test (such as copper alloy, aluminum alloy, PVC, PE, etc.) of sample of each sample with the corresponding ways to test (e.g., copper alloy with metal FP method to test), the gap between computing and standard values. Each sample test3-5 times, take the mean, and then compared to the permissible error of instruments used can know whether qualified. Error range is only a reference on the file, can choose a most appropriate error range as our company standard of instrument the range of allowable error.
(2) in view of the EDXRF there are general principles of the semiconductor detector X-ray spectrometer, the metal coating layer thickness measurementX-ray spectrum method “and other relevant national standards, each other companies and organizations have their own internal a prototype test repeatabilityAnd stability requirements. ESI the fly instrument standard, PE materials Cd, Pb, Hg, Cr in 100 PPM relative error may not be greater than 15%, Br, Cl 1000 parts per million may relative error at the time of greater than 30%.
17 if instruments frequently in standby state (often switch machine is easy to shorten the service life of the instrument), then it will have in the deviceDamage? What are the factors the influence the service life of the instrument?
Answer: (1) standby smaller influence on device performance.
(2) the factors affecting the stability of the instrument are: temperature, humidity, voltage change, etc. Usually pay attention to the good temperature and humidity.
18. In XRF testing circuit board green oil samples to ROHS control element in how to detect?
A: the physical quantity line method, the sample in polyester film glass, pay attention to the sample weight, the best may not be less than half of the sample cup, other liquid samples are the same.
19. What are the materials of the target material and how to choose it?
A: (1) Different X-ray tubes occur X-ray energy distribution is not the same. The excitation efficiency of fluorescent X-rays depends on the energy of the absorption end of each element and the X-ray energy irradiated.
(2) On the anode, according to the purpose of different, there are tungsten, molybdenum, rhodium, chromium, copper and other types. The company in SFT (fluorescent XTungsten and molybdenum are used in the X-ray film thickness meter, and rhodium and molybdenum (SEA5000) are used in the SEA (Fluorescence X-ray Analyzer).Tungsten target is suitable for Sn and Ag and other elements that produce high energy fluorescent X-rays, and is a lamp that can be fully applied to elements above atomic number 22 (Ti). Molybdenum target is suitable for the determination of elements such as Au (especially extremely thin), because the L line can be used for excitation, so it is highly efficient in the determination of light elements such as Al. Rhodium targets are suitable when performing elemental analysis. From the point of view of characteristics, it is similar to molybdenum target, but in the determination of Zr, it can be said that the element analysis of double molybdenum target can be adapted to a wider range. Since rhodium target cannot be used for the determination of Pd, molybdenum target is the standard component in SEA5000.
X-ray Fluorescence Spectral Element Analyzer FAQ – Infx Scientific Instruments
20. A measurement in the EDXRF electroplating of Pb sample, total Pb content exceeds bid, but when you take to do chemical analysis often is undetectable, most also just tens of PPM, who can tell me what reason is this?
Answer: (1) as a result of the XRF are emitted by samples to judge the inside of the test sample fluorescence X-ray element content, to have plating samples, X-ray test results for the surface layer information, after more than chemical analysis for the sample to determine the overall, because of the influence of matrix, so the two results will have larger gap.
(3) if the plating is the introduction of harmful material, to control chemical analysis approach is more reliable.
21. At the time of sample analysis, carries on the forecast of pumping air into vacuum state, this paragraph of time special long, what reason be excuse me?
Answer: (1) of different samples of vacuum time is different, some short, some long, such as alumina samples will need longer time to pumping air into vacuum state, may be related to the surface adsorption of water. In addition, the sample should check whether the system leakage, the ability of vacuum pump is decreased.
(2) if the sample is sintered, smoking is also long show that porous structure, easy adsorption air or water. So the vacuum time is long.
22. Could you please tell me the principle of X-ray fluorescence spectrometer to measure the plating thickness, and the effect of the test?Answer: (1) using fluorescence X-ray method to calculate the per unit area of quality (target element attached quantity: g/m2) than actual quality.Can’t check out the existence of the coating in the gap. With the attached amount divided by the density of the target element (g/cm3) converted to thickness (mm)Actual plating density is different, will produce the error.
(2) measurement of thin film thickness can be used without the prototype FP method, also can choose the standard curve method, standard curve method to sample and its nominal value best cover product specifications of the upper and lower.
(3) the thickness of the test there are two main methods: emission and absorption method, the former is the strength of the coating element, which is the strength of the matrix element.
23. The instrument need regular maintenance, how to do?
Answer: (1) the instrument itself does not need to maintain frequently, can at intervals appropriate to clean screen pack.
(2) if there are any instrument mechanical failure, should contact suppliers maintenance, cannot be opened device, lest self-defeating.