The Basics of Surface Plate Maintenance
Surface plates help metrologists, engineers, machinists and other users ensure flatness accuracy while manufacturing, calibrating or performing quality control checks. It’s important that these users have an absolutely flat surface on which to work to ensure the accuracy of precision measurements taken on top of the plate.
Surface plates must repeat readings from side to side to be considered in tolerance, if the readings are not consistently within the tolerance range, the surface plate will need to undergo resurfacing or relapping. Even the tiniest bit of wear could cause a pit or a hill in the surface plate, compromising its accuracy.
While all surface plates should undergo calibration at least annually, those who use their surface plate more often may want to consider more frequent calibration. Wear on the surface plate affects its accuracy, so it’s imperative that users maintain it properly. We’ve included a few basic maintenance steps below, to help you get the longest possible life out of your equipment.
Surface Plate Maintenance “Do’s”
Here are a few tips on how to properly care for surface plates, to ensure you get the longest useful life out of your investment.
1. Proper installation is key
The surface plate should be installed atop the support system with which it was manufactured. It has been lapped while sitting atop this support system, and removing it could jeopardize its accuracy.
2. Clean the surface plate often & keep it covered
Clean often, and do so with granite surface plate cleaner. The wrong cleaner could leave behind residue that attracts dust, or worse, cause the plate to wear. After cleaning, allow the plate to normalize to ensure accuracy. The appropriate amount of time ranges from 1-5 hours depending on its size.
Keep the surface plate covered when not in use to protect your equipment from nicks and foreign objects. Even debris can lead to wear, which causes dips, holes or hills over time.
3. Test often to ensure accuracy
Use a repeat reading gage often (even monthly) to ensure that your surface plate remains in tolerance. The readings must repeat from one side of the surface plate to the other to ensure accuracy.
4. Use more than one spot to conduct measurements
Be sure to use different spots on the surface plate. Over use of one spot could cause wear. If possible, rotate the plate periodically to avoid overuse in one area.
Surface Plate Maintenance “Don’ts”
Here is a short list of what not to do when maintaining your surface plate. These mistakes could cost you.
Repeat-o-meter used for measuring flatness and lapping plate used for relapping granite surface plates.
1. Don’t use if out of tolerance
Once you have determined that the granite surface plate is out of tolerance, it should be relapped before it is used again.
2. Don’t use your surface plate as a table
This will cause the surface plate to wear faster, thereby reducing its usable life. Also, if a user isn’t paying too much attention to the surface plate beneath them, there is a higher likelihood that foreign objects will be dropped on it, which could lead to chipping.
3. Use slings when moving
When using a forklift to move it, do not ever connect metal forks directly to the granite.
4. Do not use a water-based cleaner or a volatile solvent to clean the granite surface plate
Both will chill the plate. Volatile solvents could lead to wear, while water-based cleaners will cause the surface plate to retain the water, leading to rust on fasteners and other metal components.
5. Do not position your granite surface plate in a location where it could be affected by temperature
Granite is affected by changes in temperature, including drafty areas & changes in the seasons. Do not position your surface plate in such a way that it could be impacted by temperature, including underneath lighting fixtures that produce heat.
Maintenance Simplified
The basic rules of proper maintenance include keeping the surface plate clean using an appropriate cleaner, and keeping it covered when it is not in use. Both of these practices will help protect it from dust, dirt, debris & foreign objects. If you notice signs of wear, or your granite surface plate is out of tolerance, the cost of relapping it is typically significantly less than the cost of replacement. Contact your local Michelli Weighing & Measurement team with any questions you might have concerning best cleaning practices.
Need to purchase a granite surface plate?
The Michelli Weighing & Measurement team can help you find the right products for both your application and your budget. Request a quote on our website now, or contact your nearest location for more information.
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