几何尺寸与公差论坛------致力于产品几何量公差标准GD&T (GDT:ASME)|New GPS(ISO)研究/CAD设计/CAM加工/CMM测量

General

How often should my gauges/instruments be calibrated?
Do you know of any good dimensional metrology books?
What is the conversion between inches and metres?
On what basis is one inch exactly equal to 25.4 mm? Has the imperial inch been adjusted to give this exact fit and if so when?
Are inches still legal units?
Does NPL still perform calibration of items in imperial units, e.g. inch gauge blocks?
Do you still use the 'metre bar' as the length standard?
Do you calibrate micrometers and callipers?
Where can I buy engineering standards such as gauge blocks, angle gauges etc?
How do I calculate the compression of a cylinder between flat parallel anvils?
I am starting up a new laboratory. What do I need to consider?
Does NPL calibrate test sieves?
Where can I get my theodolite calibrated?
Does NPL still calibrate sextants?
Is there a difference between accuracy and uncertainty?