REAN
Multipurpose X-ray fluorescence energy dispersive spectrometer
- High speed of analysis
- Detection limits from 1 ppm (10-4%)
- Analysis of elements from 6С to 92U simultaneously
- Possibility of non-destructive analysis of large samples
- Analysis automation (autosampler for up to 144 samples)
TECHNICAL DESCRIPTION
Purpose
The instrument is intended for rapid non-destructive elemental X-ray fluorescence analysis of solid, liquid and powder substances. It is possible to measure prepared monolithic, powder and tablet-pressed samples as well as the samples of any shape and size without any preliminary preparation. The elements from 6С to 92U are analyzed simultaneously.
Features
- Multipurpose X-ray fluorescence spectrometer
- Elements from 6С to 92U are analyzed simultaneously
- The range of determination of chemical elements content: from 1 ppm to 100%
- Liquid and solid samples of various shapes and unlimited sizes
- Measurements in air, in vacuum and the atmosphere of helium
- Illuminator and video camera for visual inspection of the measurement area
- Automatic change of primary radiation filters
- Automatic sample changer for up to 144 samples
- Automatic qualitative and quantitative analysis
- Quantitative analysis by means of the fundamental parameters method without the use of standard samples
Operation principle
The operation principle of the analyzer is based on the excitation of sample atoms and subsequent detection of the X-ray fluorescence spectrum of the material under study. The energies of the characteristic lines of the spectrum correspond to chemical elements contained in the sample, and their intensities are proportional to concentrations of the corresponding elements.
An X-ray tube with a side window is used as a source of primary X-ray radiation. If necessary, one of the primary radiation filters is automatically installed between the sample and the X-ray tube. The filters are used to increase the sensitivity of the spectrometer for certain elements. Depending on the object and task, it is possible to change the primary radiation collimators in order to form an irradiation spot of the required size. When the sample is irradiated with X-rays, the atoms of the analyte are excited, which causes the emission of secondary characteristic radiation. Fluorescent radiation is detected by a silicon drift detector cooled by Peltier elements. The signal from the detector is processed by an electronic circuit and converted into a spectrum. The positions of the peaks in the spectrum correspond to the characteristic lines of the elements, and the peak heights (areas) are proportional to the radiation intensity.
The X-ray tube and the detector are located under the sample, which makes it possible to fix the distance between the sample and the detector and improve the reproducibility of the measurement results. Samples in cuvettes are placed in a measurement chamber. Single-sample cuvettes (42 mm in diameter) can be automatically rotated to average the result over the surface of the sample. Large samples that do not fit in cuvettes can be placed on the top panel of the instrument after removing the automatic sample changer and the upper part of the measurement chamber. In this case, a special insert is used that does not allow the object to fall into the measurement chamber, and a protective screen is installed on the upper panel of the analyzer. For visual inspection of the analysis area, an illuminator and a video camera are installed in the instrument.
To determine “light” elements (from 6С to 20Ca), air is pumped out of the measurement chamber by a fore-vacuum pump. If it is impossible to carry out measurements in vacuum, for example, as in the case of analysis of liquid and large-sized samples (with the upper part of the measurement chamber removed), the measurements are carried out in the atmosphere of helium.
Automatic installation of the cuvettes into the measurement chamber is performed by a sample changer (optional). The sample changer is an automated three-axis manipulator. Cuvettes with samples are installed on removable trays. At the same time, 2 sample trays can be installed in the instrument. The trays can hold cuvettes of various sizes from 10 to 40 mm in diameter. The maximum capacity of the autosampler is 144 samples.
The analyzer is linked with a computer. The instrument control is carried out using special software. Various operating modes of the software make it possible to measure and process spectral information for both routine analysis and scientific research.
Delivery package of the analyzer
The base package includes:
- analyzer (analytical unit)
- set of cuvettes and cuvette holders
- software for working with the spectrometer
- set of test samples
- set of holders for microobjects
- set of spare tools and accessories
Additional options:
- automatic sample changer
- computer
- printer
- vacuum system
- helium gas system
- protective screen for working without the upper part of the measurement chamber
- special cuvettes and holders for samples of non-standard sizes
TECHNICAL CHARACTERISTICS OF THE SPECTROMETER
| X-ray tube type | Side-window type |
| Maximum rating of X-ray tube power supply | Ua up to 50 kV; Ia up to 1 mА; P up to 50 VA |
| X-ray tube anode material | Rh (Mo, W, Ag - optional, to be agreed with the customer) |
| X-ray tube primary radiation filtering parameters |
Automatic installation and change of 10 filters:
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| X-ray collimation | From 1 mm to 8 mm |
| Detector | Silicon drift detector with electric cooling |
| Spectral information measurement channels |
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| Energy range | 1 — 40 keV |
| Energy resolution | < 130 eV (on the MnKα line) |
| Sample loading |
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| Cuvette inner diameter |
Single-sample cuvette – ∅ 42 mm (can be changed on customer request) Cuvettes for 2, 3, 6 samples – ∅ 20, 16 и 10 mm respectively Sample holder for microobjects – ∅ 1 mm, inserted into ∅ 10 mm cuvette |
| Sample chamber atmosphere |
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| Radiation safety | The instrument is freed from radiation control in accordance with corresponding certificate |
| Power consumption (220 V) |
Without fore-vacuum pump – up to 500 W With fore-vacuum pump* — up to 1000 W |
| Analytical unit dimensions | 555 × 565 × 265 mm |
| Analytical unit weight | 46 kg |
| Personal computer interface | USB |
| Operating system support |
Windows |
* — additional options
MAIN FUNCTIONS OF THE SPECTROMETER SOFTWARE
| Spectrometer control |
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| Base of standard samples |
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| Qualitative analysis |
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| Spectrum processing |
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| Spectrum comparison |
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| Methods of quantitative analysis |
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| Matrix effects evaluation | Available |
| Package processing of multiple spectra | Available |
| Creation of reports on measurement results | Available |
| Recalculation of measurement results on compounds | Available |
| Spectrum search |
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| Database of materials | Available, with the ability to add new materials |
METROLOGICAL PARAMETERS OF THE SPECTROMETER
| Range of analyzed elements | 11Na (Kα) — 92U (Lα) (optionally — from 6С (Kα), to be agreed with the customer) |
| Spectral range | 1 — 40 keV |
| Energy resolution on the MnKα line | < 130 eV |
| Maximum concentration of analyzed elements | 100% |
| Minimum concentration of analyzed elements | From 0.0001% to 0.03% — depending on the matrix |
| Long-term stability of the analyzer (relative standard deviation of the output signal) | Less than 0.3% |
| Inherent instrument error | Less than 0.3% |
| Sample analysis time | From 5 s |
SOFTWARE DESCRIPTION
The software provides the ability to manage the instrument, control the measurement process and analyze the acquired spectral information. Various implemented modes of the software make it convenient both for routine analysis by laboratory assistants and for various studies by high-level specialists.
The software interface is divided into two user parts: measurement mode and expert mode.
Measurement mode
In this mode, programs for conducting a series of measurements are set and the main parameters are defined: current and voltage of the X-ray tube, exposure time, the necessary primary radiation filter, sample rotation, and turning on the fore-vacuum pump or purging the measurement chamber with helium. Parameters can be automatically loaded and quantitative analysis performed using previously saved measurement methodologies.
By means of a video camera, the required investigation area on the sample is selected. Also in this mode, control over the main components of the instrument is performed.
The measurement mode makes it possible to edit and fill in the bases of standard samples, which are used to build calibration graphs for quantitative analysis.
Also, in the measurement mode, the energy scale is calibrated and the instrument metrological verification is carried out.
Implemented separately is quick analysis mode. Using this mode, the user can measure any samples with one click of a button, without thinking about the choice of parameters for measurements and processing of spectra. During the measurements, in real time mode, a unique algorithm is applied which makes it possible to automatically calculate concentrations of detected elements and also search for the most probable grade of material.
Expert mode
This mode is intended for processing the acquired spectral information, as well as for developing methodologies for the rapid analysis of samples.
The spectra acquired using the measurement mode can be mathematically processed in various ways. When carrying out qualitative analysis (which is possible in automatic mode), the lines of elements are marked with chemical symbols. When doing so, the escape peaks and double peaks are taken into account.
Spectra can be compared with each other, subtracted, added and averaged. The search for measured spectra that are most similar to the current one is also possible. The background component is modeled in various ways to increase the accuracy of the analysis.
For quantitative analysis, several calculation methods are available: linear regression, the Lucas-Tooth method with and without alpha correction, and the standard-background method based on incoherently scattered radiation measurements. Additionally, the methodology editor is provided which makes it possible to create custom formulas for calculating concentrations which take into account errors in standard samples for individual elements. In the absence of standard samples, the standardless method of fundamental parameters can be used.
The developed analysis methodologies are saved for serial measurements. The methodologies include all measurement parameters, selected standard samples, formulas for calculating concentrations including ones that take into account errors in standard samples for individual elements, and also some other parameters.
Using package processing of spectra, fast processing of similar spectra in the same way is possible.
The expert mode also includes functions for recalculating measurement results onto compounds, calculating detection limits, editing the base of standard samples and other auxiliary functions.
The results of measurement processing and calculation of concentrations can be output in the form of custom reports.
SOFTWARE FEATURES
The measurement mode makes it possible to carry out:
- control of the main instrument components
- metrological verification of the instrument
- energy scale calibration
- setting measurement parameters: current and voltage of the X-ray tube, exposure time, installation of primary filters, sample rotation and use of vacuum, if necessary
- creation of measurement series programs
- autosampler control
- editing of the base of standard samples
- automatic measurement and calculation of concentrations according to developed analysis methodologies
- rapid standardless quantitative analysis
Algorithms and programs for mathematical processing and modeling of spectra and background include:
- qualitative analysis (possible in automatic mode)
- comparison, subtraction and averaging of spectra
- various methods for modeling spectra and background
- taking into account escape peaks and double peaks
- semiquantitative analysis by means of the fundamental parameters method (standardless)
- quantitative methods for calculating concentrations: linear regression, the Lucas-Tooth method with and without alpha correction, the standard-background method based on incoherently scattered radiation measurements
- methodology editor with the ability to create custom formulas and take into account errors in standard samples for individual elements
- creation of automatic measurement methodologies with a full description of measurement parameters, mathematical processing of spectra and calculation options
- ability to add software modules to solve specific problems (specialized analysis methodologies, identification, sorting, grading, etc.)