Precision Thermal Expansion

Southern Research has developed innovative facilities for measuring thermal expansion with ultra-high accuracy from 300 K to below 30 K and from -30ºC to 130ºC. Using interferometry and a proprietary optical flagging system, CTE accuracy of better than 20 parts-per-billion (ppb) is standard. For materials that do not tend to bend or flex, CTE accuracy of better than 10 parts-per-billion is possible (based on an 8" sample with a 20 K ΔT). Our testing capabilities include:

Sample Characteristics

• May range in size from 1 cm to 1 meter in length
• Test coupons (1 to 8 inches long)
• Tubes and struts (up to 1 meter)
• Honeycomb core material
• Low-CTE composite samples (various configurations)
• Low-CTE glass samples (mirror segments and machined specimens)

Absolute Accuracy

• Expansion data generated on NIST Cu SRM 736
• NIST traceable silicon diode temperature sensors
• No reference standards or back-out factors
• Cosine error minimized
• Abbé error largely self-canceling
• Optics thermal drift self-canceling
• Large data sets with continuous data density

Precision to PPB

• Quantification of composite TE
• Multiple thermal cycles
• Acceptance and performance testing

Cryogenic Capability

• Temperatures below 30 K
• Same accuracy and precision as room temperature-data
• Data collected on cool-down and warm-up