What is Positive Material Identification (PMI)?
Positive Material Identification (PMI) is a non-destructive testing (NDT) technique used to verify the chemical composition and alloy grade of metals and materials. PMI testing ensures that materials used in pipelines, pressure vessels, valves, and other critical components meet required specifications — preventing costly failures and ensuring regulatory compliance. Star OES Services performs PMI analysis using Optical Emission Spectroscopy (OES), X-Ray Fluorescence (XRF), and Laser-Induced Breakdown Spectroscopy (LIBS).
What is Non-Destructive Testing (NDT)?
Non-destructive testing (NDT) refers to a broad range of inspection and evaluation methods that analyze material properties without causing damage to the component. Common NDT methods include positive material identification (PMI) via OES or XRF, ultrasonic testing, and radiographic testing. Star OES Services specializes in PMI-based NDT using portable and laboratory-grade spectrometers, serving oil & gas, petrochemical, pipeline, and power generation industries from Houston, TX.
What PMI methods do you use — OES, XRF, or LIBS?
We use all three primary PMI methods depending on the application and alloy type. Optical Emission Spectroscopy (OES) provides the most accurate elemental analysis and is ideal for carbon steel, low-alloy steels, and light elements such as carbon and sulfur. X-Ray Fluorescence (XRF) is fast, non-contact, and excellent for stainless steel and exotic alloys. Laser-Induced Breakdown Spectroscopy (LIBS) via the SciAps Z903 handles carbon content measurement in the field. Our team will recommend the right PMI method for your specific application.
What is the difference between OES and XRF for PMI?
Both OES and XRF are used for positive material identification (PMI), but with different strengths. OES uses a spark to excite the sample and is the gold standard for carbon steel alloy verification — particularly accurate for light elements (carbon, sulfur, phosphorus) that XRF cannot reliably detect. XRF is faster, non-destructive to the surface, and excels at stainless steel and high-alloy materials. For comprehensive NDT programs, both methods are often used in combination. Star OES Services carries and services both types of instruments.
Do you provide on-site PMI testing services in Houston, TX?
Yes. Star OES Services is based in Pasadena, TX in the greater Houston area and provides on-site positive material identification (PMI) testing throughout Texas and the Gulf Coast. We also travel across the United States and internationally for client engagements. Our mobile OES and handheld XRF/LIBS instruments are fully field-deployable for in-situ PMI testing on pipelines, pressure vessels, valves, and structural components.
What industries require PMI testing and NDT services?
Positive material identification (PMI) and non-destructive testing (NDT) are required across oil & gas, petrochemical refining, pipeline construction and integrity, power generation, fabrication shops, and quality control laboratories. Regulatory standards such as API 578, ASME, and ASTM specifications mandate PMI testing to verify that critical pressure-containing components are fabricated from the correct alloy material, helping prevent catastrophic failures from material mix-ups.
What PMI instruments does Star OES Services use?
Our instrument fleet includes the Hitachi PMI Master Smart (mobile OES), ARCMET 8000 (mobile OES), BELEC Compact Port HLC (mobile OES), BELEC Vario Lab (laboratory OES), SciAps Z903 (handheld LIBS for carbon content), and Oxford X-MET 8000 (handheld XRF). All instruments are regularly calibrated to ensure accurate, reliable PMI and NDT results for every engagement.
Do you offer PMI instrument rental?
Yes. We offer rental of mobile OES, handheld XRF, and LIBS instruments for positive material identification (PMI) and non-destructive testing (NDT) applications. Available rental instruments include the Hitachi PMI Master Smart, ARCMET 8000, X-MET 8000, SciAps Z903, BELEC Compact Port HLC, BELEC Vario Lab, and FOTRIC thermal imaging cameras. Contact us at 713-670-4447 or sales@staroes.com for availability and pricing.
