SS reference block to calibrate for CS

[SEJohn]

Hi All,
Structural Engineer here. Every so often I need a thickness measurement on existing structural steel (carbon steel). I have access to a Olympus 45MG, but it only has a 303 SS reference block.
I am usually measuring material that is .1" to 1" thick and I would like to be within a few percent of actual thickness.
Should I be using a 1018 CS step block for calibration before measuring CS structural members?
How far off would I be if I used the 303 SS reference block to calibrate before testing CS?
Thanks in advance.

 

Your accuracy requirement is not that high, so provided you have the SS cal block and the work material at the same temperature you will probably be alright.

I would invest in a ferritic steel cal block and be relieved of all concerns.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[gtaw]

You are using a straight beam transducer with either a single or double crystal. You could use a stepped wedge. If you have a machine shop near by, they could make you one or you can make one for your use by getting a couple of steel blocks and verify their thickness with a dial caliper. Two thicknesses should do the trick, say a 3/8-inch and a 1-inch block you calibrate with.

Best regards - Al