Last Updated:
The Total Radiation Pyrometer collects all wavelengths of radiation from a hot body to measure its temperature. Option A (200°C to 1500°C) is incorrect — the lower end of 200°C is too low. Total Radiation Pyrometers require a minimum temperature of around 800°C to collect sufficient radiation for accurate measurement. 1500°C as the upper limit is also incorrect — the range extends much higher. Option B (500°C to 2000°C) is incorrect — again the lower limit of 500°C is wrong. At 500°C the radiation collected is insufficient for accurate readings. The upper limit of 2000°C is also short of the actual 3000°C range. Option C (800°C to 2700°C) is incorrect — this is the range of the Optical Pyrometer (Wien's law based), NOT the Total Radiation Pyrometer. The Optical Pyrometer uses Wien's radiation law and covers 800°C to 2700°C. Option D (800°C to 3000°C) is CORRECT — the Total Radiation Pyrometer, based on Stefan-Boltzmann law (E = σT⁴), can measure temperatures from 800°C to 3000°C. This slightly wider range (up to 3000°C) compared to the Optical Pyrometer (up to 2700°C) is its key advantage.
FAQ
Common questions and clear answers for this topic.
Heat is a form of energy that transfers between objects or systems due to a temperature difference, moving from a hotter body to a cooler one until thermal equilibrium is reached.
