The advantages and disadvantages of PMI (Positive Material Identification)

In our piping industry,PMI is popularly used to inspect the material whether conformed with the demand.The reason why PMI widely used is it has below advantages:

  1. Flexible sampling methods of PMI can save the loss caused by sampling for the detection and analysis of rare and precious metals.
  2. High test rate-PMI can set multi-channel instant multi-point acquisition, and real-time output through the calculator.
  3. PMI can achieve non-destructive testing without destroying the sample for some mechanical parts, which is convenient for non-destructive testing.
  4. PMI analysis speed is faster, and it is more suitable for pre-furnace analysis or on-site analysis so as to achieve rapid detection;
  5. The accuracy of the PMI analysis result is based on the basis of the chemical analysis standard samples.
PMI for ASTM A182 F11 flange

PMI for ASTM A182 F11 flange

Except for the advantages,there are also some disadvantages for PMI.

  1. PMI is difficult to accurately detect non-metals and elements between metals and non-metals.
  2. PMI is not an original method and cannot be used as an arbitration analysis method, and the test results cannot be used as a basis for national certification.
  3. Due to the relative monopoly of the products of various enterprises, the purchase and maintenance costs of PMI tool are relatively high, and the cost performance is low.
  4. A large number of representative samples are required for chemical analysis modeling of PMI, which is obviously impractical for small batch samples.
  5. PMI result is easily affected by external or internal factors such as optical system parameters, and the problem of curve nonlinearity often occurs, which has a greater impact on the accuracy of the detection results.

Haihao Group,as a professional supplier of piping products,we often use the PMI tool to inspect the steel pipes,pipe fittings or flanges.We could make full use of the PMI advantages and make up the PMI disadvantages by using the lab chemical analysis to guarantee the material quality.So if you need piping products,contact us