Expert Surface Plate Measurement and Calibration Services

Workshop surface plate accuracy depends on grade, size, and maintenance history. New Grade AA plates typically hold flatness within 0.000025 inches per square foot, Grade A within 0.000050 inches, and Grade B within 0.000100 inches. However, accuracy degrades through wear and requires regular verification. Sarkinen Calibrating measures actual flatness using NIST-traceable methods and provides documented results showing current accuracy levels compared to original specifications.

Calibration frequency depends on usage intensity, part tolerance requirements, and quality system standards. High-use inspection environments typically require annual calibration, while moderate-use applications may extend to 18-24 months. ISO 17025 and AS9100 quality systems often mandate documented calibration intervals. We recommend annual verification for critical measurement applications and can help establish appropriate intervals based on your specific usage patterns.

Surface plates lose accuracy primarily through wear from sliding parts and measurement tools across the surface. Heavy or concentrated loads create localized depressions, while improper cleaning techniques can cause scratches. Temperature variations, improper support, and foundation settling also contribute to flatness changes. Regular calibration identifies these issues early, allowing corrective action before measurement errors affect production quality.

Many worn surface plates can be re-lapped or resurfaced to restore flatness, though this depends on the extent of wear and remaining material thickness. Our condition evaluation identifies whether your plate is a candidate for restoration or requires replacement. Re-lapping is typically cost-effective for plates with moderate wear, while severely damaged plates or those worn beyond minimum thickness specifications require replacement.

Our calibration service includes flatness measurement using multiple techniques, Moody Plot analysis showing wear patterns, leveling verification, condition assessment for damage or excessive wear, and a detailed calibration certificate with NIST-traceable results. We also provide recommendations for continued use, maintenance practices, and timing for future calibration or refurbishment needs.

On-site calibration typically takes 2-4 hours depending on plate size, condition, and measurement point density required. We schedule service to minimize production disruption and can often work during shift changes or non-production periods. Our local Portland OR and SW Washington presence allows flexible scheduling with faster response times than distant providers.

Yes, every calibration includes a detailed certificate showing measurement results, measurement uncertainty, traceability to NIST and International Standards, technician identification, and calibration date. Our certificates meet ISO/IEC 17025 requirements and are accepted by quality auditors, customer inspections, and regulatory agencies. Certificates clearly document your surface plate's current accuracy status.

We primarily serve manufacturing facilities throughout Portland OR and SW Washington with on-site calibration services. Our local presence provides faster scheduling and response times compared to out-of-area providers. We also support customers in Oregon, Northern California, and Idaho. Contact us to discuss service availability and scheduling for your location.