Metal composition analysis and testing procedures
Date：2026-03-17 09:21:52 Classification
：【question】 Visits：
The application process for metal composition analysis and testing typically includes the following key steps. You can refer to the following process based on your needs (whether for quality control, import/export customs clearance, or R&D improvement):
I. Application Process
1. Clarify Testing Needs
Before contacting a testing agency, you need to clarify the following information so that the agency can provide a quote and arrange testing:
Sample Type: Is it raw material (e.g., steel plate, aluminum ingot), finished product (e.g., screws, machine parts), or suspected impurities/foreign matter?
Testing Purpose: Is it full elemental analysis (qualitative and quantitative), grade identification (determining whether it is 304 or 316 stainless steel, etc.), or testing only specific elements (e.g., only measuring carbon content)?
Applicable Standards: Are there any designated national standards (GB), ASTM, ISO, or enterprise standards?
2. Select a Testing Agency
Qualification Confirmation: Choose a third-party testing agency with CMA (China Metrology Accreditation) and CNAS (China National Accreditation Service for Conformity Assessment) qualifications (e.g., Dezewei Testing CNAS Registration No.: L8083). Reports issued by such agencies have legal validity and can be used for import/export, bidding, and judicial arbitration.
Capability Matching: Confirm that the organization possesses the corresponding metal testing capabilities.
3. Application Submission and Completion of the Commission Form
Contact the organization's customer service or sales personnel to complete the "Testing Application Form" or "Commissioned Testing Agreement."
The form must specify: sample name, quantity, testing items, applicable standards, client information, and report delivery method (electronic/paper version).
4. Sample Submission/Retrieval
Sample Submission for Testing: The client mails or delivers the samples to the laboratory themselves. This is the most common method.
On-site Testing: For samples that cannot be disassembled, such as large equipment or steel structure bridges, on-site testing can be requested from laboratory personnel using portable equipment (such as a handheld XRF spectrometer).
5. Payment and Testing
After receiving and confirming the samples, the organization will send a quotation. After payment, the laboratory will officially arrange testing.
The testing cycle is usually 3-5 business days. Expedited services typically incur an additional fee.
6. Report Issuance
After testing, the institution will issue a test report bearing the CMA/CNAS seal.
If you have any objection to the results, you can apply for a retest within the specified time.
II. Common Testing Methods
The laboratory will select different methods based on your needs and sample characteristics:
1. Direct Reading Spectroscopy (OES):
Features: Fast speed, high accuracy.
Applications: Quantitative analysis of common elements (C, Si, Mn, P, S, Cr, Ni, etc.) in metals such as steel, aluminum, and copper; the preferred method for grade identification.
2. X-ray Fluorescence Spectroscopy (XRF):
Features: Non-destructive testing, simple sample preparation.
Applications: Rapid screening of stainless steel and alloy steel; RoHS hazardous element detection.
3. Inductively Coupled Plasma Emission/Mass Spectrometry (ICP-OES/MS):
Features: Low detection limit; can measure trace elements.
Applications: High-purity metal analysis; trace impurity element analysis.
4. Chemical Titration/Gravimetric Method:
Characteristics: A classic chemical analysis method, used as the basis for arbitration analysis.
Applications: Analysis requiring extremely high precision or in situations where standards are unavailable.
III. Sample and Data Preparation
To ensure smooth testing, please note the following when submitting samples:
Sample Quantity:
Block/Rod Samples: Generally, the sample size should be large enough to fit on the spectrometer excitation stage (typically diameter > 10 mm, thickness > 3 mm). The surface must be polished smooth, free of oxide scale, oil, and coatings.
Powder/Flake Samples: Usually require 5-10 grams or more.
Liquid Samples: Sufficient quantity must be provided, and the container must be resistant to acid and alkali corrosion.
Data Preparation: Providing approximate material information (e.g., "suspected aluminum alloy") helps the laboratory select an appropriate working curve.
IV. Precautions
Surface Treatment: If the metal is galvanized, painted, or rusted, the surface coating/oxide layer must be removed first to expose the base metal; otherwise, the test results will be inaccurate.
Small samples: Such as welding wires and small parts may require mounting; additional costs should be discussed with the laboratory in advance.
Report Purpose: If the report is intended for court proceedings or acceptance of major projects, this must be stated when commissioning the service to ensure the rigor of the process.
Shen Gongwang Security: 44030602006947