Quiz

Over the typical maximum range of temperatures experienced on the shop floor (say, 50° F to 140° F, or 10° C to 60° C) Coefficients of Expansion (COE) for the most commonly machined metals are practically linear. However, COEs are typically expressed in handbooks only to within +/- 10% or so, because of uncertainties. Can you associate the following approximate COEs (expressed in parts per million per ° F or "ppm/°F") with their respective metals?

1) The approximate COE of Steel is:

1. 12.2 ppm/°F
2. 6.5 ppm/°F
3. 10.0 ppm/°F
4. 5.5 ppm/°F
   

Your answer # 1: select a b c d
Correct answer:   show b

2) The approximate COE of Aluminum is:

1. 12.2 ppm/°F
2. 6.5 ppm/°F
3. 10.0 ppm/°F
4. 5.5 ppm/°F

Your answer # 2: select a b c d
Correct answer:   show a

 

 

3) The approximate COE of powdered metals is:

1. 12.2 ppm/°F
2. 6.5 ppm/°F
3. 10.0 ppm/°F
4. 5.5 ppm/°F
   

Your answer # 3: select a b c d
Correct answer:   show c

 

1. 32° F (0° C)
2. 50° F (10° C)
3. 68° F (20° C)
4. 86° F (30° C)

Your answer # 4: select a b c d
Correct answer:   show c

 

 

1. a precise gage has greater resolution than an accurate gage
2. a precise gage has better R & R than an accurate gage
3. there is no difference
4. an accurate gage gives results which are closest to true dimension, while a precise gage is repeatable, even if inaccurate.

 

Your answer # 5: select a b c d
Correct answer:   show d

 

 

6) Which "elements" of a measurement system (gage) can contribute to temperature induced error? A good example of such a system can be found here.

a.  workpiece
b.  gage fixture
c.  setting master
d.  all of the above

Your answer # 6: select a b c d
Correct answer:   show d

 

 

1. .0004 in / 0.010 mm
2. .0006 in / 0.015 mm
3. .0008 in / 0.020 mm
4. .0010 in / 0.025 mm

Your answer # 7: select a b c d
Correct answer:   show c

 

 

1. .0002 in / 0.005 mm
2. .0003 in / 0.0075 mm
3. .0004 in / 0.010 mm
4. .0006 in / 0.015 mm

Your answer # 8: select a b c d
Correct answer:   show c

 

 

9) What do the letters "TEI" stand for?

a.  Theorized Expansion Indicator - an estimate of thermal expansion coefficient
b.  Thermal Error Index - an ANSI defined estimate of overall thermal error in a measurement system
c.  Temperature Equalization Inversion - the amount of thermal error offset experienced when setting master and gage vary in temperature by the same amount
d.  Thermal Energy Input - the amount of thermal energy generated in a part as a result of a production process

Your answer # 9: select a b c d
Correct answer:   show b

 

 

10) What is a Full Electronic Temperature Compensation System? Albion's TComp II system is just one of our systems in this category.

a.  a system of temperature sensors and an electronic controller which senses temperatures of master, workpiece and gage fixture during measuring operations and generates a real-time net correction for thermal errors
b.  a sensor and electronic interface which senses the temperature of parts while they are being measured
c.  a method by which temperature is controlled at nominal temperature
d.  an off line computer into which an operator punches temperatures and dimensions in order to calculate thermal errors

Your answer # 10: select a b c d
Correct answer:__ show a

 

 

11) Approximately how much of the thermal error in a measurement should an Electronic Temperature Compensation System consistently eliminate?

a.  80% or better
b.  92% or better
c.  65% or better
d.  50% or better

Your answer # 11: select a b c d
Correct answer:__ show b

 

 

12) What is the principal benefit of a Temperature Compensation System?

a.  measurements are always given at reference temperature, regardless of actual temperatures
b.  the system constantly displays the temperatures of workpiece and gage during measuring operations
c.  a cheaper coolant can be used in metal cutting processes
d. machine operators can take the afternoon off

 

Your answer # 12: select a b c d
Correct answer:__ show a

 

 

Scoring: If you scored more than ten correct, you must have done some excellent research, or maybe you have a temperature compensation system already installed. Eight to ten right is impressive - you already have a good start on the subject. Less than eight correct - maybe you need to find out more about this technology of the present and future.