Precision Measurement

Southern Research offers clients proven expertise in precision measurement for a range of applications including precision space structures, optical benches, and assessment of lot-to-lot variability of materials. Our highly skilled engineers have maintained longstanding, trusted relationships with clients, and they offer extensive experience in designing custom precision optical metrology systems to meet our clients' specialized needs. As an additional benefit, our precision thermal expansion testing methodology is well-suited to a range of sample sizes from 1 cm to 1 meter in length.

Precision Coefficient of Thermal Expansion Testing Capabilities

Southern Research has developed innovative facilities for measuring thermal expansion (PTE) with ultra-high accuracy from 300 K to below 30 K and from -30°C to 130°C. 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).

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

Structure Distortion Measurement Capabilities

Southern Research has also developed a unique facility for measuring structural distortion in air from 275 K to 350 K for clients who may have this specialized need. Distortions due to thermal gradients and load changes are monitored with 0.05 arc-second precision using an autocollimator to measure relative tilt between targets on the part.

Applications for this custom testing capability include:

• Satellite structures
• Optical benches
• Tube twist
• Thermal distortion
• Hysteresis
• Load deformation