Remember there are caveats with any tool. Caliper type micrometers with spinner adjustments:
1) only measure the largest piece in the sample, and the sample presented to the tool is very, very small
2) can actually crush the largest piece by using the spinner to close the gap, thereby resulting in a smaller reading than it should be (can compensate for this at some level by having a pressure guage affixed to it)
3) only measure in one axis. ie, if you put a pencil in it and measure the width of it, you'll get a small reading. however, it's unlikely the pencil would be presented in such a fashion as to have the tool 'see' it from eraser to lead - which would be a much, much larger reading. those types of shapes exist in chocolate.
Still a very useful tool, just need to be aware of what it's actually telling you and what it's limitations are 8-)
Muchas gracias Sebastian.
Is there a reasonably priced option that addresses these limitations of micrometers?
It's important to have the right tool for the right job. Each tool has it's limitations, and once you ID the right tool, it's just as important to understand how to use the tool. For the vast majority of folks on this site, a micrometer will likely be the right tool - as long as it's used right. For this group of people, actually, the mouth itself is probably the right tool. Given sufficient experience, I've found that I've been able to 'resolve' down to 15-16 um particle size (largest particle), w/in a +/- 4/5 um range. Most of you making chocolate here aren't going to need a deep, deep understanding of particle size, shape, or distribution, and spending lots and lots of money to get a number that your tongue could probably tell you may not be money well spent.
It's important to ask yourself "why do i need this piece of information, and what will i do with it". If the # itself isn't important to you , and really the information you're looking for is 'do i have a chocolate with a good mouthfeel or not' then just put it in your mouth 8-)