- Joined
- Dec 14, 1998
- Messages
- 4,870
Every hardness tester has one or more cert coupons. These are small disks that are certified by the factory to gov standards as to the hardness. They are used to calibrate the machine and make sure it is reading the right rc. First this is just a fact and boring but I felt after buying a wilson (my fav) this weekend I wanted to post about the importance of the coupon. When I bought this old wilson the fellow told me it was off by 1
1/2 points. After looking it over and giving some tlc I inspected the hardness coupon. It had been used to check the hardness on both sides. AAAAAAAAAAAAINNNNNNNT
When you use you test coupon please only check your machine using one side of the coupon. This test puts a dimple in the face of the coupon. If you use both sides it causes the coupon to not be flat . If it is not flat you will get a bad reading .
This ended in a great way for me. I resurfaced the coupon with 2000 grit paper on a surface plate and now the machine reads 61.5 rc every time. YIPPPPEEEEEEEE....perfect Within a half a point.
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Web Site At www.darrelralph.com
1/2 points. After looking it over and giving some tlc I inspected the hardness coupon. It had been used to check the hardness on both sides. AAAAAAAAAAAAINNNNNNNT
When you use you test coupon please only check your machine using one side of the coupon. This test puts a dimple in the face of the coupon. If you use both sides it causes the coupon to not be flat . If it is not flat you will get a bad reading .
This ended in a great way for me. I resurfaced the coupon with 2000 grit paper on a surface plate and now the machine reads 61.5 rc every time. YIPPPPEEEEEEEE....perfect Within a half a point.
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Web Site At www.darrelralph.com