Description
IQQ Standard Block - Test Efficiency Standards - Quantitative Quality Indicators
The Quantitative Quality Indicator (QQI), also known as a "SHIM" standard, is a standard with artificial discontinuities used to verify the direction and intensity of the magnetic field in magnetic particle testing. Available in several different configurations, QQIs are thin steel wafers with engraved patterns in circular and cross-shaped shapes to provide indications in all directions. The steel alloy and notch dimensions, as specified in AS 5371, are designed to provide indications when the base part is magnetized to at least 30 gauss. These wafers can adapt to curved part surfaces and are typically attached using permanent adhesives. QQIs are also used to balance multidirectional fields and increase productivity by minimizing magnetization "shots." They contain artificial indications that simulate subsurface discontinuities and are considered high-sensitivity standards, widely used in automotive and aircraft part inspections.
Benefits
- Its basic configuration features a circular discontinuity and a cross-shaped discontinuity. It detects longitudinal and transverse fields.
- It quickly verifies the performance of the magnetization process.
Accordance
- AS 5371
- ASME BPVC Sec. V Article 7
- ASTM E709
- ASTM E1444
- ASTM E3024
Usage Recommendations
Leave the hermetically sealed packaging intact until ready to use. The standards are made of low-carbon steel and must be protected from corrosion when not in use. To prevent corrosion, the QQIs are coated with a protective resin and stored in protective plastic packaging.
Before use, the protective resin must be removed from both sides of the QQI using SKC-S, acetone, or a suitable solvent.
The part and the QQI must be clean and dry before application. Place the QQI with the defective side down in direct contact with the part being inspected and secure it firmly. To secure the QQIs, use non-fluorescent adhesive tape on the sides or a high-adhesion glue.
Ensure that the surface opposite the defect is not covered and that there is no gap between the indicator and the part. When using the standard as a process control part, ensure that there is no adhesive covering the indicator itself. This method also applies when the indicator is left in place for preventive maintenance applications.
Store the QCIs in solvent after use. For more details, see ASTM E1444.
