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.
- To determine whether the carbon, chromium and nickel dilutions in pressure vessel overlays are within the range required for optimized corrosion resistance
- 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
- To insure that the correct grade of an alloy has been welded to a certain equipment circuit in petrochemical plants and refineries
- 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
- For semi-quantitative analysis to provide information regarding the concentrations of specific elements in a metal sample
- For grade Identification to:
- Determine the concentrations of elements in an alloy
- Identify whether or not the tested sample meets the user specified grade
ADVANTAGES
- Equipment is highly portable
- Results are obtained on-the spot with experienced technicians performing analysis
- Access to power source is required
- Sample must have an overall thickness greater than 0.5 mm (0.020 inch)
- Burn or alteration occurs in the test material up to a depth of 0.25 mm (0.010 inch) depending on the analysis performed
- Test must be performed within specific temperature criteria to ensure both the accuracy of the analysis and the integrity of the equipment.
- Ambient temperature must be between -20 °C(-4 °F) and +40 °C (104 °F)
- Material to be analyzed must be at a temperature of no greater than 75 °C (167 °F)
- 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
- Curvature of the specimen
- Requires a seal to maintain the Argon purge and prevent Oxygen contamination
- Where the sample is curved or found the diameter must be greater than 25 mm (1 inch)
- A dam made of plasticine may be required to maintain the purge
- Magnetic samples will cause disruption to the arc and should not be analyzed
- Clean surface representative of the material is required