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Difficulty: HardTemperature Scales and Thermometric Properties

Match each experimental temperature measurement requirement on the left with the most appropriate thermometric instrument on the right based on its thermometric property and operational characteristics.

  • Standard calibration reference requiring high accuracy over a wide range using pressure variations at constant volumeConstant-volume gas thermometer
  • High-precision steady-state measurement using electrical resistance variation where slight thermal response lag is permissiblePlatinum resistance thermometer
  • Measurement of rapidly changing temperatures at a localized point using thermal electromotive force (e.m.f.)Thermocouple
  • Non-contact measurement of extremely high temperatures of glowing bodies using radiant energy intensityOptical pyrometer

Answer

The correct pairings match each measurement requirement to its corresponding thermometric instrument based on its fundamental thermometric property: standard reference calibration pairs with the constant-volume gas thermometer; high-precision steady measurement pairs with the platinum resistance thermometer; rapid localized temperature change measurement pairs with the thermocouple; and non-contact high-temperature measurement pairs with the optical pyrometer.
Each instrument is correctly matched according to the specific physical property that changes measurably with temperature (PP, RR, e.m.f., and radiation intensity) and its operational suitability.

Step-by-Step Solution

1
Analyze requirement 1: standard reference calibration using gas pressure at constant volume.
Identified thermometric property as pressure PP at constant volume VV, which defines the constant-volume gas thermometer.
Gas thermometers closely approximate the absolute thermodynamic scale and serve as calibration standards.
2
Analyze requirement 2: high-precision steady measurement using resistance variation with thermal lag.
Identified thermometric property as electrical resistance RR, which corresponds to the platinum resistance thermometer.
Platinum wire resistance changes predictably with temperature, providing high accuracy for stable temperatures.
3
Analyze requirement 3: rapid localized temperature measurement via thermal e.m.f.
Identified thermometric property as thermoelectric voltage (e.m.f.), which corresponds to the thermocouple.
The small thermal mass of thermocouple junctions allows low response times for fast transient measurements.
4
Analyze requirement 4: non-contact measurement of glowing bodies using radiation.
Identified physical principle as thermal radiation intensity, corresponding to the optical pyrometer.
Pyrometers detect infrared/visible radiation, avoiding structural melting associated with direct contact at extreme temperatures.

Key Concept

Thermometric Properties and Operational Limits of Thermometers
Estimated Time:2m 0s
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Topics

Temperature Scales and Thermometric Properties

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