Vickers hardness calc 1

[Mett87]

Just a quick one, when inputing values into excel spreadsheet to calculate microvickers hardness ive noticed it to be about 50 points high. The machine is reading correct and also if i input the d1 and d2 values from the test block cert they also read around 50 points high. I dont see how this is possible because theres nothing in the calculation that could make it only slightly higher.

 

[TVP]

Are you using this equation?

HV = 1854.4 x P/d²

where:
P = force, gf
d = mean diagonal length of the indentation, μm