Niton Handheld Alloy AnalyzerAs a key equipment for rapid detection of alloy element composition and content, the accuracy of its detection results directly affects material sorting, quality control, and engineering safety. To ensure that the metrological performance of the equipment meets the requirements, it is necessary to strictly follow this calibration specification for operation. This specification is applicable to the regular calibration and daily calibration verification work of the Niton series handheld alloy analyzer.
1、 Core preparation requirements before calibration
1. Personnel and Qualification Requirements
Calibration personnel need to have instrument operation qualifications, be familiar with the working principle of the Newton analyzer (X-ray fluorescence spectroscopy) and relevant standards such as the "Calibration Specification for X-ray Fluorescence Spectroscopy Analysis Instruments", and master the calibration process and emergency response measures.
If it is a third-party calibration, the executing personnel must hold relevant project calibration qualification certificates issued by legal metrology technical institutions to ensure that the calibration behavior is legal and effective.
2. Preparation of equipment and standard materials
Verify instrument information: Record the analyzer model, serial number, last calibration date, and historical calibration data. Check the appearance of the instrument for any damage, display screen for normal operation, and ensure sufficient battery power (or connect an external power source to ensure stable power supply).
Selection of standard materials: Standard alloy samples that have been certified by national metrology must be used. The types and content ranges of elements in the standard materials should cover the commonly used detection range of the instrument and match the tested alloy matrix (such as iron-based, aluminum based, copper based, etc. corresponding to specialized standard samples); The standard substance must be within its validity period, with no surface damage such as rust, oil stains, scratches, etc., and stored in accordance with requirements (such as sealing against moisture and avoiding direct sunlight).
Preparation of auxiliary tools: Prepare a cleaning cloth, anhydrous ethanol, a dedicated calibration bracket (if available), a temperature and humidity meter, and a calibration record form to ensure that the calibration environment temperature and humidity meet the requirements (usually temperature 15-30 ℃, relative humidity ≤ 75%, no strong electromagnetic interference, vibration, and dust).
3. Instrument pre-processing
Turn on the instrument and preheat it according to the instructions (usually 15-30 minutes) to ensure stable internal temperature and avoid temperature fluctuations affecting calibration accuracy.
Dip a small amount of anhydrous ethanol into a cleaning cloth to wipe the instrument detection window (X-ray emission and reception window) and the surface of the standard substance, remove stains and dust, and wait for the ethanol to completely evaporate before proceeding with subsequent operations.
2、 Core calibration operation process
1. Calibration mode selection and parameter setting
Enter the instrument calibration interface, select the corresponding calibration mode (such as general alloy mode, specific element precision mode) according to the detection requirements, confirm the calibration unit (such as mass percentage%), detection time (it is recommended to use standard detection time to ensure data stability) and other parameters.
If the instrument supports multi-point calibration, a series of standard substances should be prepared in order of element content from low to high to avoid cross contamination or confusion in calibration order that may affect the results.
2. Calibration operation of standard substances
Place the standard substance steadily on a horizontal table. If using a calibration bracket, adjust the height of the bracket to ensure that the instrument detection window is tightly attached to the surface of the standard substance without gaps, ensuring that the instrument does not shake during the detection process.
Start the calibration program, the instrument emits X-rays and receives fluorescence signals. After the detection is completed, the instrument automatically displays the detection values of each element; Each standard substance needs to be tested three times, and the average value is taken as the calibration test value for that standard substance.
Enter the standard value and detection average value of the standard substance into the instrument calibration system, and the system will automatically generate a calibration curve; If it is manual calibration, the correction factor should be calculated based on the deviation between the two, accurately entered into the instrument, and saved.
Replace the standard substances of different substrates and repeat the above steps to complete multi substrate calibration, ensuring the accuracy of the instrument in detecting different types of alloys.
3. Key performance calibration verification
Detection limit calibration: Select standard substances containing low concentrations of target elements, test three times and calculate the detection limit to ensure compliance with the specified values in the instrument manual (such as common element detection limit ≤ 0.01%).
Repetitive calibration: Conduct 6 consecutive tests on the same standard substance, calculate the relative standard deviation (RSD), and require RSD ≤ 5% (high content elements ≤ 3%) to ensure the stability of instrument detection.
Linear error calibration: Select 5 standard substances with different contents covering the detection range, and draw a calibration curve after detection. The linear correlation coefficient r should be ≥ 0.995 to ensure a good linear relationship between the element content and the detection signal.
3、 Requirements for post-processing and validation after calibration
1. Calibration result determination and processing
If the linear correlation coefficient, repeatability, detection limit and other indicators of the calibration curve meet the technical requirements and testing standards of the instrument, the calibration is judged to be qualified, and the calibration qualification mark is marked on the instrument, indicating the calibration date and the next calibration date.
If the calibration indicators are not qualified, it is necessary to first check whether the standard substance is invalid, whether the instrument detection window is contaminated, or whether the instrument hardware is faulty; After excluding external factors, recalibrate. If it still does not meet the requirements, contact the after-sales technical personnel of Thermo Fisher Scientific (the company owned by the Niton brand) for repair and debugging before recalibration.
2. Calibration records and data archiving
Fill in details《Niton Handheld Alloy AnalyzerThe Calibration Record Form includes instrument information, calibration date, calibration personnel, standard substance information (model, number, expiration date), environmental temperature and humidity, standard and detection values of each element, calibration curve parameters, calibration result determination, etc., to ensure that the records are true, complete, and traceable.
Organize and archive calibration records, copies of standard substance certificates, calibration certificates, and other materials, with a retention period of no less than 3 years; If it is a third-party calibration, the original calibration report must be retained.
3. Daily calibration verification
Before daily use, it is necessary to perform single point calibration verification with quality control standard substances. If the deviation between the detected value and the standard value exceeds ± 5% (or the range specified in the instrument manual), it should be recalibrated in a timely manner.
Calibration cycle: Under normal operating conditions, a comprehensive calibration is conducted every 6 months; If the instrument is used frequently and in harsh environments (such as high temperature, high humidity, and high dust), the calibration cycle should be shortened to 3 months to ensure that the instrument is always in a qualified state.