Precision Measurements And Instruments Corporation (PMIC) Laboratory, specialists in measuring the Coefficient of Thermal Expansion, Coefficient of Moisture Expansion, and Thermal Conductivity of materials.
- Coefficient of Thermal Expansion
- Using LVDT (Quartz Dilatometer) or Michelson laser Interferometry
- Coefficient of Moisture Expansion
- Thermal Conductivity
- Our Thermal Conductivity is regularly utilized by the Nuclear Industry
- Mechanical Properties
- Optical Properties
- Specific Heat
- Non Destructive Testing and Evaluation
- Electrical Properties, and Metrology
Please visit our Testing Services area for more details.
CTE Testing (Coefficient of Thermal Expansion)
PMIC measures CTE primarily with Michelson laser interferometry or quartz dilatometry. Guided by ASTM Test Method E289, the Michelson interferometer measures real-time thermal expansion by detecting shifts in the fringe pattern created when a laser beam is split to travel to two points on the test specimen. The fringe pattern is created by interference between the two reflected beams, which have traveled different distances. Each shift corresponds to half of the laser’s wavelength, or 316 nm (12.456 micro-inches) for a helium-neon laser in vacuum. CTE can be measured to 10 parts per billion per degree Kelvin (10-8/K°). For specimens in which larger CTEs are to be measured, the quartz dilatometer (ASTM E228 and D696) offers resolution to 0.05 parts per million/K° (5 × 10-8/K°). The dilatometer measures the expansion of a specimen situated between two quartz plates.
CME Testing (Coefficient of Moisture Expansion)
CME is measured by tracking the change in weight and length of a sample held in a humidified chamber. Mass is measured on a balance with resolution of 10-4g. Changes in length are measured using a PMIC-developed hanging-sample dilatometer that has a resolution of 3 micro-inches. Microyield testing imparts small, short stresses to determine the stress needed to create a plastic strain of one part per million (microstrain).
We specialize in highly accurate thermal testing. We can get the job done. Contact us for all of your testing needs.
Importance of Testing
The CME Factor
Moisture absorption in polymer matrix composites results in a change in mass, and in some cases, dimensional changes as well. This could develop into a major design concern in some applications such as the composite materials used in spacecraft, where it could result in defocusing of optical images in space telescopes, for example. PMIC is capable of measuring the moisture absorption vs. time at select relative humidities, and maximum moisture content at specified humidities and temperatures, and also the moisture diffusivity (rate of moisture uptake).