ASME B89.1.13:2001 pdf free download

ASME B89.1.13:2001 pdf free download.MICROMETERS.
ASME B89.1.13 is intended to provide the essential requirements for micrometers as a basis for muwal understanding between manufacturers arid consumers. Outside, inside, and depth micrometers are described in the Standard.
2 DEFINONS
backlash: a relative movement between interacting mechanical parts, resulting from looseness [ASME B5.54M-1992 (R1998)]. In this Standard, backlash is further defined as the rotation of the spindle, in the opposite direction of the initial reading, before spindle moves in a linear direction. This condition is typically caused by looseness of fit between the lead screw and adjusting nut.
bias: systematic error of the indication of a measuring instrument (VIM).
eccentricity: the distance between the geometric center or axis of the body and its axis of rotation.
end shake: the amount of spindle movement, when an axial force is applied in the direction of the spindle alternating towards the anvil and away from the anvil, without rdtating the spindle.
error (of indication) of a measuring in.strwnent: indication of a measuring instrument minus a true value of the corresponding quantity (VIM).
NOTE: This ccqt apphes mainly where the illatnimeat is compared IC) a ,ele,eaCt slandaid.
flatness. the condition of a surface having all elements in one plane (ASME Y)4.5M-1994),
ma.rimu’n permissible error (MPE): extreme values of an error permitted by specifications, etc., for a given measuring instrument (VIM).
parallelism: the condition of a surface or center plane. equidistant at all points from a datum plane or axis. equidistant along its length from one or more datum planes or a datum axis (ASME Y14.5M-l994).
If the gage is accurate at the reference temperature, and the coefficients of expansion of both the work pan and gage are approximately the same, the effect of the deviation from 20°C (68°F) is less than if the parts were of different materials.
83.4 Difference due to Dissimilar Materials
If parts made of aluminum or magnesium are checked by steel gages, an allowance for temperature differences. with reference to 20°C (68°F), must be madc as the expansion coefficient of aluminum is approximately twice that of steel, while the coefficient of magnesium is even greater.
83.5 Soak Time
Gages should be stored in a constant temperature room before they are inspected to ensure they are nearly the same temperature as the measurement laboratory. The amount of soak time required depends on the size of the gage and the desired accuracy.
B4 HUMIDITY
The relative humidity of the atmosphere in a gage laboratory should preferably be kept under 45% to minimize the possibility of corrosion. In general, the air conditioning system of a laboratory should remain in operation at all times. This is both because the change in humidity may cause corrosion and because there arc delays while insti-unients and gages reach the proper temperature on the day when the laboratory is reopened.
85 CLEANUNESS
Cleanliness is an important requirement for a good gage laboratory. Small particles of dirt may cause senous errors in precision measurements and bring about excessive wear of precision instruments.