Which device serves as a temperature reference during RTD calibration?
A. Pressure gauge
B. Reference thermometer
C. Voltmeter
D. Ammeter
View Answer
Answer: B
Explanation:
A Reference Thermometer is used as the temperature standard during RTD calibration. It provides a highly accurate temperature measurement against which the RTD’s reading can be compared.
During calibration:
- The RTD and reference thermometer are placed in the same temperature source (such as a temperature bath or dry block calibrator).
- The temperature is stabilized.
- The RTD reading is compared with the reference thermometer reading.
- Any error or deviation is recorded and corrected if necessary.
Why a Reference Thermometer is Used
High accuracy
Traceable calibration standards
Reliable temperature reference
Used in calibration laboratories and industries
Why the Other Options Are Incorrect
Pressure Gauge
- Measures pressure, not temperature.
Voltmeter
- Measures electrical voltage.
- Cannot serve as a temperature standard.
Ammeter
- Measures electrical current.
- Not used as a temperature reference.
Common RTD Calibration Setup
- Temperature Bath or Dry Block Calibrator
- Reference Thermometer
- RTD Under Test
- Temperature Calibrator or Indicator
Because calibration requires a highly accurate temperature standard, the Reference Thermometer is the device that serves as the temperature reference.
Therefore, Option B (Reference Thermometer) is the correct answer.