CCT Practice Questions
Prepare for CCT with more than an answer.
- Level
- Technician
- Valid for
- 3 years
Domains covered on the exam 5
- General Metrology24%
- Measurement Systems20.8%
- Calibration Systems22.4%
- Measurement Uncertainty and Applied Math20%
- Quality Systems and Standards12.8%
- 1
A technician is calibrating a digital thermometer. They place both the standard PRT (Platinum Resistance Thermometer) and the Unit Under Test (UUT) into a stable liquid bath at the same time, allow them to stabilize, and record the readings of both simultaneously. Which measurement method does this procedure represent?
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Correct answer: B
Placing a standard and a UUT in the same environment (like a liquid bath) and reading them simultaneously is a classic Transfer or Comparison measurement method. Indirect measurement involves calculating a value from other measured variables.
- 2
A digital pressure indicator has a specified range of 0 to 1,000 psi. The manufacturer's specification for accuracy is ±(0.1% of Reading + 0.05% of Full Scale). If the indicator is currently displaying a measurement of 500 psi, what is the total acceptable tolerance for this specific reading?
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Correct answer: C
To calculate the total tolerance: First, calculate 0.1% of the Reading (500 psi * 0.001) = 0.5 psi. Second, calculate 0.05% of Full Scale (1000 psi * 0.0005) = 0.5 psi. Add them together: 0.5 psi + 0.5 psi = ±1.0 psi.
- 3
While adjusting a 4-20 mA temperature transmitter, a technician notes that the output reads exactly 4.00 mA at the 0°C lower limit, but it reads 19.85 mA at the 100°C upper limit. Which specific adjustment method must the technician utilize to correct the output at the upper limit without shifting the lower limit?
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Correct answer: A
Spanning is the process of adjusting the gain or upper end of the instrument's range. Since the zero point (4.00 mA) is already correct, adjusting the span will correct the upper limit (bringing 19.85 mA to 20.00 mA) by changing the slope of the response.
- 4
A metrologist is tasked with calibrating a high-precision photometer used in an automotive lighting manufacturing facility. The calibration requires establishing traceability to the SI base unit for luminous intensity. Which of the following defines this specific SI base unit?
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Correct answer: D
The candela is the SI base unit of luminous intensity. Lumen is a derived unit for luminous flux, and lux is a derived unit for illuminance. The mole is the SI base unit for amount of substance.
- 5
A commercial calibration laboratory is updating its quality manual to explicitly define how measurement traceability is realized and disseminated. Which TWO of the following statements correctly describe acceptable paths or principles for establishing unbroken traceability to the International System of Units (SI)? (Select TWO)
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Correct answer: B, D
Traceability can be validly established through unbroken chains of comparisons linking to SI units, which is typically demonstrated by utilizing a National Metrology Institute (NMI) or an ISO/IEC 17025 accredited laboratory operating within its approved scope.
Procuring primary reference materials or calibration services directly from an NMI (like NIST in the US) provides a direct link to the realization of the SI units.
- 6
During a high-workload period, a laboratory's primary reference pressure controller is sent out for its annual calibration. The technical manager must decide if a secondary transfer standard can be substituted to calibrate a customer's working gauge. The customer's gauge has a stated accuracy of ±0.25% of full scale. The proposed substitute standard has an expanded uncertainty of ±0.10% of full scale. Based strictly on standard industry practices for Test Uncertainty Ratios (TUR), what is the correct evaluation of this substitution?
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Correct answer: B
TUR is calculated as the Tolerance of the UUT divided by the Uncertainty of the Standard. Here, 0.25 / 0.10 = 2.5. A 2.5:1 TUR falls short of the industry-preferred 4:1 ratio. Therefore, substituting this standard would likely require a risk assessment, guard-banding, or customer concession.
