Hi,
I have two basic measurement questions.
First, if using a measuring gauge, I wonder from what point to what other point measurements are taken. For instance, if using an ordinary ruler, should the object being measured be aligned with the center of the lines, or one of the edges? All these years, I've simply tried to maintain consistency. Given the potential for varying thicknesses of lines on gauges, etc., I'd assume that measurements should be taken from the middle lines. Now that I'm hoping to measure with precision, this is something I really should know for sure.
Second, I have a pair of calipers. I don't know how to find the thickness of things with precision. For instance, if I clamp a pen between the the jaws, I can take a measurement of the diameter. However, if I slowly increase the distance between the jaws, I can see that the digital readout is indicating an increase in distance, yet the pen will still held between the jaws. There's obviously compression at play, so I gradually open the jaws until the pen falls out. I assume that this is as precise a measurement as I'm going to get.
For objects that can't be picked up between the jaws, this becomes more problematic.
These instances aren't really important, they just illustrate a general problem. I'd guess I'd have the same sorts of problems when using highly precise micrometers, etc. So, what are the general guidelines? Is there a youtube video on this? Thanks.
I have two basic measurement questions.
First, if using a measuring gauge, I wonder from what point to what other point measurements are taken. For instance, if using an ordinary ruler, should the object being measured be aligned with the center of the lines, or one of the edges? All these years, I've simply tried to maintain consistency. Given the potential for varying thicknesses of lines on gauges, etc., I'd assume that measurements should be taken from the middle lines. Now that I'm hoping to measure with precision, this is something I really should know for sure.
Second, I have a pair of calipers. I don't know how to find the thickness of things with precision. For instance, if I clamp a pen between the the jaws, I can take a measurement of the diameter. However, if I slowly increase the distance between the jaws, I can see that the digital readout is indicating an increase in distance, yet the pen will still held between the jaws. There's obviously compression at play, so I gradually open the jaws until the pen falls out. I assume that this is as precise a measurement as I'm going to get.
For objects that can't be picked up between the jaws, this becomes more problematic.
These instances aren't really important, they just illustrate a general problem. I'd guess I'd have the same sorts of problems when using highly precise micrometers, etc. So, what are the general guidelines? Is there a youtube video on this? Thanks.