- #1
eli64
- 133
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HI, please forgive me if I am introducing a topic that has been hashed about already, if so I would appreciate a link to the discussion (I tried searching the threads but didn't find one that really seem to talk abou this in a generalized way) or the thread moved to the appropriate forum.
I'm having a discussion with someone who is in science (engineering student who is an industry coop) but who adamantly believes that sig figs in the real world are useless. I don't doubt that in many instances that sig figs are tossed by the wayside when the impact of a few decimals here doesn't seem to make a difference but I was wondering how industry in general views this in their measurements.
His example was that in his job, his group measures the diameter of a groove in a disc, first with a ruler that is measures up to a certain distance and gives a value to 2 dec places, the rest of the measurement is done with a caliper that gives the remaining measurement to 3 dec places. The two measurements are added and they report the diameter to 3 decimal places. The issue I raised was that since the first instrument only measured to 2 decimal places, the whole measurement should have only 2 decimal places. He contends that it is more accurate to report to 3 decimal places since the caliper measured the critical remainder of the distance. They have a tolerance of 0.006 to adhere to.
What is your view of this practice? thanks for any responses
I'm having a discussion with someone who is in science (engineering student who is an industry coop) but who adamantly believes that sig figs in the real world are useless. I don't doubt that in many instances that sig figs are tossed by the wayside when the impact of a few decimals here doesn't seem to make a difference but I was wondering how industry in general views this in their measurements.
His example was that in his job, his group measures the diameter of a groove in a disc, first with a ruler that is measures up to a certain distance and gives a value to 2 dec places, the rest of the measurement is done with a caliper that gives the remaining measurement to 3 dec places. The two measurements are added and they report the diameter to 3 decimal places. The issue I raised was that since the first instrument only measured to 2 decimal places, the whole measurement should have only 2 decimal places. He contends that it is more accurate to report to 3 decimal places since the caliper measured the critical remainder of the distance. They have a tolerance of 0.006 to adhere to.
What is your view of this practice? thanks for any responses