Precision Measurement Technician
Certification Examination Questions
And Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant
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Question 1
Which of the following instruments is most appropriate for measuring the inside
diameter of a small bore hole to an accuracy of ±0.0001 inch?
A. Vernier caliper
B. Outside micrometer
C. Telescoping gauge with outside micrometer
D. Small-hole gauge with bench micrometer
*Answer: D. Small-hole gauge with bench micrometer
Rationale: Small-hole gauges are specifically designed for measuring small bores
(typically 0.125–0.500 inch) and when used with a bench micrometer or digital
indicator can achieve ±0.0001 inch accuracy. Vernier calipers are limited to ±0.001
inch. Telescoping gauges are better for larger bores and require transfer
measurement, introducing error. Outside micrometers cannot reach inside bores.
Question 2
What is the total indicated reading (TIR) if a dial indicator shows +0.0005 inch at
the high point and -0.0003 inch at the low point during a circular runout
inspection?
A. 0.0002 inch
B. 0.0005 inch
,C. 0.0008 inch
D. 0.0016 inch
*Answer: C. 0.0008 inch
Rationale: TIR is the absolute difference between the maximum and minimum
readings. TIR = |+0.0005| + |-0.0003| = 0.0005 + 0.0003 = 0.0008 inch. Option A
(0.0002) is the algebraic sum, which is incorrect for TIR. Option D doubles the
range erroneously.
Question 3
A gauge block set is certified at 68°F (20°C). If the blocks are used at 72°F and the
coefficient of thermal expansion is 6.5 × 10⁻⁶ per °F, what is the expansion per
inch of length?
A. 0.000013 inch
B. 0.000026 inch
C. 0.000039 inch
D. 0.000052 inch
*Answer: B. 0.000026 inch
Rationale: ΔL = L × α × ΔT = 1 inch × 6.5×10⁻⁶/°F × (72-68)°F = 1 × 6.5e-6 × 4 = 26e-
6 = 0.000026 inch. Option A is for a 2°F difference; C is for 6°F; D is for 8°F.
Question 4
Which type of surface plate is least affected by temperature changes and provides
the highest stability for precision layout work?
A. Cast iron
B. Granite
C. Steel
D. Ceramic
*Answer: B. Granite
Rationale: Granite has a very low coefficient of thermal expansion (about 3–4 ×
10⁻⁶/°F), excellent damping properties, and is non-magnetic and non-rusting. Cast
,iron and steel are more thermally sensitive and prone to corrosion. Ceramic is
stable but expensive and less common for general use.
Question 5
When using a sine bar to measure a 30° angle with a 5-inch center distance, what
gauge block height is required?
A. 2.500 inches
B. 2.886 inches
C. 4.330 inches
D. 5.000 inches
*Answer: A. 2.500 inches
Rationale: Height = L × sin(θ) = 5 × sin(30°) = 5 × 0.500 = 2.500 inches. Option B is
for tan(30°) with a 5-inch base; C is for 60°; D is for 90°.
Question 6
What is the least count of a vernier height gauge with a main scale division of
0.025 inch and a vernier scale having 25 divisions covering 0.600 inch?
A. 0.0005 inch
B. 0.0010 inch
C. 0.0002 inch
D. 0.0001 inch
*Answer: B. 0.0010 inch
Rationale: Least count = main scale division - (vernier scale length / number of
divisions) = 0.025 - (0.600/25) = 0.025 - 0.024 = 0.001 inch. Option A (0.0005)
corresponds to a 50-division vernier; C and D are for finer resolutions.
Question 7
Which of the following errors is most likely to occur when using a micrometer with
a worn anvil face?
, A. Parallax error
B. Cosine error
C. Zero error (systematic)
D. Abbe error
*Answer: C. Zero error (systematic)
Rationale: A worn anvil changes the zero reference point, causing a constant offset
(systematic error) in all measurements. Parallax is a reading error; cosine error
results from misalignment; Abbe error arises from offset between measurement
and scale axes.
Question 8
In optical comparators, what is the primary function of the telecentric lens
system?
A. To magnify the image 50×
B. To eliminate parallax by ensuring collimated light
C. To provide color correction
D. To focus the light source
*Answer: B. To eliminate parallax by ensuring collimated light
Rationale: Telecentric lenses produce parallel light rays, so the image size does not
change with object distance, eliminating parallax and enabling accurate edge
detection. Magnification is a separate function; color correction is not primary;
focusing is not the lens's main role.
Question 9
A part is measured at 20.05 mm using a calibrated digital caliper. If the calibration
certificate states a correction factor of -0.02 mm at 20 mm, what is the true value?
A. 20.03 mm
B. 20.07 mm
C. 20.02 mm
D. 20.08 mm
Certification Examination Questions
And Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant
Download Pdf
Question 1
Which of the following instruments is most appropriate for measuring the inside
diameter of a small bore hole to an accuracy of ±0.0001 inch?
A. Vernier caliper
B. Outside micrometer
C. Telescoping gauge with outside micrometer
D. Small-hole gauge with bench micrometer
*Answer: D. Small-hole gauge with bench micrometer
Rationale: Small-hole gauges are specifically designed for measuring small bores
(typically 0.125–0.500 inch) and when used with a bench micrometer or digital
indicator can achieve ±0.0001 inch accuracy. Vernier calipers are limited to ±0.001
inch. Telescoping gauges are better for larger bores and require transfer
measurement, introducing error. Outside micrometers cannot reach inside bores.
Question 2
What is the total indicated reading (TIR) if a dial indicator shows +0.0005 inch at
the high point and -0.0003 inch at the low point during a circular runout
inspection?
A. 0.0002 inch
B. 0.0005 inch
,C. 0.0008 inch
D. 0.0016 inch
*Answer: C. 0.0008 inch
Rationale: TIR is the absolute difference between the maximum and minimum
readings. TIR = |+0.0005| + |-0.0003| = 0.0005 + 0.0003 = 0.0008 inch. Option A
(0.0002) is the algebraic sum, which is incorrect for TIR. Option D doubles the
range erroneously.
Question 3
A gauge block set is certified at 68°F (20°C). If the blocks are used at 72°F and the
coefficient of thermal expansion is 6.5 × 10⁻⁶ per °F, what is the expansion per
inch of length?
A. 0.000013 inch
B. 0.000026 inch
C. 0.000039 inch
D. 0.000052 inch
*Answer: B. 0.000026 inch
Rationale: ΔL = L × α × ΔT = 1 inch × 6.5×10⁻⁶/°F × (72-68)°F = 1 × 6.5e-6 × 4 = 26e-
6 = 0.000026 inch. Option A is for a 2°F difference; C is for 6°F; D is for 8°F.
Question 4
Which type of surface plate is least affected by temperature changes and provides
the highest stability for precision layout work?
A. Cast iron
B. Granite
C. Steel
D. Ceramic
*Answer: B. Granite
Rationale: Granite has a very low coefficient of thermal expansion (about 3–4 ×
10⁻⁶/°F), excellent damping properties, and is non-magnetic and non-rusting. Cast
,iron and steel are more thermally sensitive and prone to corrosion. Ceramic is
stable but expensive and less common for general use.
Question 5
When using a sine bar to measure a 30° angle with a 5-inch center distance, what
gauge block height is required?
A. 2.500 inches
B. 2.886 inches
C. 4.330 inches
D. 5.000 inches
*Answer: A. 2.500 inches
Rationale: Height = L × sin(θ) = 5 × sin(30°) = 5 × 0.500 = 2.500 inches. Option B is
for tan(30°) with a 5-inch base; C is for 60°; D is for 90°.
Question 6
What is the least count of a vernier height gauge with a main scale division of
0.025 inch and a vernier scale having 25 divisions covering 0.600 inch?
A. 0.0005 inch
B. 0.0010 inch
C. 0.0002 inch
D. 0.0001 inch
*Answer: B. 0.0010 inch
Rationale: Least count = main scale division - (vernier scale length / number of
divisions) = 0.025 - (0.600/25) = 0.025 - 0.024 = 0.001 inch. Option A (0.0005)
corresponds to a 50-division vernier; C and D are for finer resolutions.
Question 7
Which of the following errors is most likely to occur when using a micrometer with
a worn anvil face?
, A. Parallax error
B. Cosine error
C. Zero error (systematic)
D. Abbe error
*Answer: C. Zero error (systematic)
Rationale: A worn anvil changes the zero reference point, causing a constant offset
(systematic error) in all measurements. Parallax is a reading error; cosine error
results from misalignment; Abbe error arises from offset between measurement
and scale axes.
Question 8
In optical comparators, what is the primary function of the telecentric lens
system?
A. To magnify the image 50×
B. To eliminate parallax by ensuring collimated light
C. To provide color correction
D. To focus the light source
*Answer: B. To eliminate parallax by ensuring collimated light
Rationale: Telecentric lenses produce parallel light rays, so the image size does not
change with object distance, eliminating parallax and enabling accurate edge
detection. Magnification is a separate function; color correction is not primary;
focusing is not the lens's main role.
Question 9
A part is measured at 20.05 mm using a calibrated digital caliper. If the calibration
certificate states a correction factor of -0.02 mm at 20 mm, what is the true value?
A. 20.03 mm
B. 20.07 mm
C. 20.02 mm
D. 20.08 mm
