L77F85

I recently purchased a lightly used Rimac valve spring tester from a local machine shop that was going out of business. It appears to be in excellent condition & I got a good deal on it. I purchased the Rimac calibration spring #0093 to check accuracy. I'm a little concerned because the recommended calibration spring values are different then the actual values that I got when checking the Rimac tester. How accurate is it supposed to be? I've read that springs lose their strength over time. Could it be possible that the calibration spring lost some tension from sitting on the shelf or is it more than likely the Rimac tool itself? It appears that the accuracy decreases the more the spring is compressed. Here are the values. Btw it is the Rimac 0-500lb model.

Rimac Calibration spring #0093 values (written on the calibration spring card)
149lbs @ 2.75", 315lbs @ 2.5" & 446lbs @ 2.312"

Actual measured spring values 140lbs @ 2.75", 304lbs @ 2.5" & 424lbs @ 2.312"

What do guys think? Useable tool or junk? Thanks in advance

nsnarsk65cutlass

I'm not an expert but i say useable for sure,adjust your calculations accordingly.

L77F85

Thanks for the reply. I'm thinking of trying another calibration spring. At least that would eliminate the problem of having a defective spring. If the measurements are close to the same then Ill adjust accordingly when measuring my own valve springs.