On-Site Surface Table & Plate Calibration Services
UKAS Accredited Surface Table & Plate Calibration Laboratory
What is a Surface Plate or Surface Table?
A Surface Plate or Surface Table is an accurately flat and stable base used for reliable, precision measurements. The primary purpose of a Surface Plate is to provide a true plane in which the accuracy of workpieces, gauges, and tools can be measured. The high degree of flatness and stability makes surface plates indispensable in tasks involving fine tolerances. Surface plates come in a variety of materials such as steel and cast iron but granite is currently the most popular due to the flatness, stability and ability to re-lap.
They are usually referred to as a surface plate when they are on a bench or more easily moved (600mm x 600mm and under). When they are larger and mounted on a purpose build frame they are more often referred to as a surface table.
Surface Table Calibration Process
Calibration is the systematic process of comparing the measurements and flatness of the surface table against a known standard or master reference. To obtain this our trained technicians will follow a series of steps when calibrating a surface table or surface plate to obtain reliable and precise results.
The surface table will initially be cleaned to ensure the surface is free from dirt, dust and debris that could interfere with the calibration results. The table will then be levelled using the adjustable bolts on a frame or levelling jacks where possible to ensure the level of the working surface has been optimised. Our technicians will then follow our internal calibration procedure, taking readings for both localised flatness (local variation) and overall flatness using a variation gauge and electronic level respectively. The results from these reading will be compared to the required tolerances and if found to be outside of these limits, re-lapping or replacing can be discussed.
Importance of Surface Table Calibration
There are many reasons and advantages to having your surface tables and surface plates calibrated at an established frequency as outlined below:
1. Ensuring Measurement Accuracy
The central purpose of a surface table or surface plate is to provide a flat, true reference. Regular calibration ensures that this reference remains accurate. Calibration detects any deviations from flatness or localized wear, allowing for corrective action before errors are introduced to the measurement system.
2. Maintaining Traceability
In regulated industries and quality management systems, all measurements must be traceable to national or international standards and regular calibration creates a documented chain of accuracy.
3. Extending Surface Table Lifespan
Proactive calibration can help identify issues such as wear patterns, chips, or surface damage at an early stage. Early detection enables timely maintenance or reconditioning, therefore extending the useful life of the surface table.
4. Upholding Quality Control
A calibrated surface table is the foundation for any quality control program. It ensures consistency and repeatability in measurement processes and supports the production of precision parts with high accuracy.
5. Compliance with Standards and Audits
Many industries require periodic calibration of all measuring equipment, including surface tables, as part of their quality assurance protocols. Auditors and certifying bodies often check calibration records during assessments and the lack of up-to-date calibration records can result in audit findings.
Consequences of an Uncalibrated Surface Table
When a surface table is not properly calibrated, its flatness can deviate over time due to factors such as wear, accidental impacts and environmental conditions. The consequences of relying on an uncalibrated surface table include:
• Measurement Errors: Even a tiny deviation from flatness can result in significant errors during quality inspections or part fabrication, leading to parts that don’t fit or function as intended.
• Compromised Product Quality: Incorrect measurements can be passed through the manufacturing process, resulting in products that fail to meet specifications, quality standards, or customer expectations.
• Increased Waste and Rework: Errors arising from an inaccurate surface table may not be apparent until later stages, causing costly scrap, rework, or recalls.
Surface Table Calibration Services - Documentation
Surface Tables calibrated on-site by OSS Calibration Ltd are furnished with a label showing the serial number, certificate number and calibration date (with recalibration dates also included if required)
Certificates are processed at our laboratory and emailed as a .pdf.
When the flatness is understood, the surface table should be used accordingly, and if any areas of concern are highlighted, these should not be used for accurate measurements. Please note that we can replace or recondition your surface table if the results are outside your requirements.
CONTACT US
On Site Services (Calibration) Ltd
10 Cavendish Avenue
Edwinstowe
Nottinghamshire
NG21 9NQ
