Metrology

Question 1

Metrology

Answer 1

Measuring dimensions

Question 2

Accuracy

Answer 2

Degree of agreement between measured dimensions

Question 3

Precision

Answer 3

Degree instrument gives repeated measurements

Question 4

Resolution

Answer 4

Smallest dimension instrument can read

Question 5

Sensitivity

Answer 5

Smallest difference in dimensions instrument can detect

Question 6

Calibration

Answer 6

Recursive process, calibrate with another calibrated instrument

Question 7

Surface plate

Answer 7

Horizontal reference plane
Non-magnetic
No thermal expansion
Wear resistant
Usually granite

Question 8

Surface plate grades

Answer 8

AA: Lab grade, controlled atmospheres, very precise
A: Inspection grade
B: Toolroom grade, used for production work in shops

Question 9

Dial indicators

Answer 9

Plunger-type indicators used for surface measurements

Question 10

Test indicators

Answer 10

Lever-type indicators used for surface measurements at smaller scale than dial indicators

Question 11

Telescoping gages

Answer 11

Used to determine internal diameter of a hole

Question 12

Gage blocks/Joe blocks/Slip gages

Answer 12

Precision ground rectangular blocks used to calibrate shop tools

Question 13

Coordinate measuring machines (CMM)

Answer 13

Either 3 or 5 axes, very high sensitivity

Question 14

Plug gages

Answer 14

Gages with external measuring surface that checks thread/hole size (go/nogo)

Question 15

Ring gages

Answer 15

Gages for checking the external diameter of a cylindrical object

Question 16

Snap gages

Answer 16

Gages to verify an outside dimension, if it fits in the gage’s gap, then you’re good

Question 17

Unilateral tolerance

Answer 17

Tolerance has unequal magnitude in each direction

Question 18

Bilateral tolerance

Answer 18

Tolerance has equal magnitude in each direction

Question 19

Maximum material condition (MMC)

Answer 19

The dimensions that allow for the largest part volume (smaller holes, larger shafts, etc)

Question 20

Least material condition (LMC)

Answer 20

The dimensions that allow for the smallest part volume (larger holes, smaller shafts, etc)

Question 21

Clearance fit

Answer 21

Mating surfaces have a gap between them
Allowance > 0

Question 22

Interference fit

Answer 22

Mating surfaces overlap each other
Allowance < 0

Question 23

Line fit

Answer 23

No gap or overlap between mating surfaces, the fit exactly
Allowance = 0

Question 24

Allowance

Answer 24

Smallest hole minus largest shaft

Question 25

Nondestructive testing techniques

Answer 25

Liquid penetrant
Magnetic particle inspection
Radiography

Question 26

Liquid penetrant

Answer 26

Capillary action and bright dye used to reveal cracks, seams, and pores

Question 27

Magnetic particle inspection

Answer 27

When magnetized, particles take the shape and size of defects

Question 28

Radiography

Answer 28

X-rays are used to see variations in density/thickness

Question 29

Types of quality assurance

Answer 29

1st article inspection
Production inspection
Total quality management
Random sampling
Qualitative
Quantitative

Question 30

Dispersion of a data set

Answer 30

Same as range

Question 31

Lean manufacturing

Answer 31

Aims to eliminate waste, inefficiency, and unneeded expenses

Question 32

Agile manufacturing

Answer 32

Modular and flexible system that can be shifted and swapped as needed