Are you trying to measure the size of the brick, or the pitch of the bricks when they are interconnected? Steve (...) (25 years ago, 21-Jul-99, to lugnet.general, lugnet.faq)
The basic issue I'm raising is determining the engineer's standard for the "horizontal spacing" from one stud to the next. I think this is what you're calling "the pitch". The most commonly quoted dimension standard among LEGO users is this (...) (25 years ago, 21-Jul-99, to lugnet.general, lugnet.faq)