What are the different Flatness Testing Methods for Surface Plates?

As we all know, Surface plate is a working standard. But how actually we can measure the flatness of the surface plate to ensure it can be used as a working standard. There are various methods are available for flatness testing. We have listed them below. 1. Using Two footed twisting Gauge/Three footed twisting Gauge 2. Spirit Level Method 3. Auto Collimator 4. Beam Comparator 5. Laser Beam 6. Comparing with Liquid surface 7. Interference Method Read the full article: https://extrudesign.com/flatness-testing-methods-surface-plates/ #Metrology #MechanicalEngineering #BasicEngineeringConcepts #ExtruDesign Website - https://extrudesign.com YouTube Channel - https://www.youtube.com/extrudesign DailyMotion - https://www.dailymotion.com/extrudesign