Field Spectroscopy – Spark Testing

Spark testing involves the use of a field portable electronic instrument specifically designed to analyze metals and measure and quantify the chemical content. The instrument gives elemental content of metallic and non-metallic compounds which make up the material under analysis and will give the percentage content of the elements present. IRISNDT uses the Metorex ARC-MET 8000 for Field Spectroscopy analysis.


  1. To determine whether the carbon, chromium and nickel dilutions in pressure vessel overlays are within the range required for optimized corrosion resistance
  2. To evaluate the carbon equivalent of an old part to be re-welded.  Based on this, one can assess what special welding procedures may be required to make reliable repairs
  3. To insure that the correct grade of an alloy has been welded to a certain equipment circuit in petrochemical plants and refineries
  4. To sort materials.  Based on the test, one determines whether different materials have been inadvertently mixed or whether batches of parts were made from the same raw materials
  5. For semi-quantitative analysis to provide information regarding the concentrations of specific elements in a metal sample
  6. For grade Identification to:
  7. Determine the concentrations of elements in an alloy
  8. Identify whether or not the tested sample meets the user specified grade


  1. Equipment is highly portable
  2. Results are obtained on-the spot with experienced technicians performing analysis
  3. Access to power source is required


  1. Sample must have an overall thickness greater than 0.5 mm (0.020 inch)
  2. Burn or alteration occurs in the test material up to a   depth of 0.25 mm (0.010 inch) depending on the   analysis performed
  3. Test must be performed within specific temperature criteria to ensure both the accuracy of the analysis and the integrity of the equipment.
  4. Ambient temperature must be between -20 °C(-4 °F)   and +40 °C (104 °F)
  5. Material to be analyzed must be at a temperature of   no greater than 75 °C (167 °F)
  6. Testing is set up to analyze specific base models and will analyze for samples with an Iron, Nickel, or Copper base only. Analysis on other bases will render inaccurate readings
  7. Curvature of the specimen
  8. Requires a seal to maintain the Argon purge and prevent Oxygen contamination
  9. Where the sample is curved or found the diameter must be greater than 25 mm (1 inch)
  10. A dam made of plasticine may be required to maintain the purge
  11. Magnetic samples will cause disruption to the arc and should not be analyzed
  12. Clean surface representative of the material is required