Related Experiment Video
Updated: Jun 16, 2026
09:10
The Frequency Domain Thermoreflectance Technique for Thermal Property Measurements
Published on: December 5, 2025
Errors associated with interferometric measurement of convective heat transfer coefficients
Applied Optics
|February 20, 2010
Summary
Differential interferometers offer greater accuracy for measuring heat transfer coefficients compared to Mach-Zehnder systems. This study analyzes refraction and end effects, finding the differential interferometer superior for convective heat transfer measurements.
Area of Science:
- Optical metrology
- Heat transfer
Background:
- Interferometric systems are susceptible to errors like refraction and end effects.
- Accurate measurement of convective heat transfer coefficients is crucial in various engineering applications.
Purpose of the Study:
- To analytically study refraction and end effects in interferometric systems.
- To compare the suitability of Mach-Zehnder and differential interferometers for measuring heat transfer coefficients.
- To present experimental measurements of convective heat transfer coefficients using a differential interferometer.
Main Methods:
- Analytical estimation of refraction and end effects for Mach-Zehnder and differential interferometers.
- Experimental setup involving a specially designed test section for free convection to water.
- Measurement of convective heat transfer coefficients at varying Rayleigh numbers.
Main Results:
- Refraction and end effects were found to be larger in Mach-Zehnder interferometers than in differential interferometers.
- Differential interferometers showed potential for more accurate heat transfer coefficient measurements.
- Experimental results compared satisfactorily with published data for Rayleigh numbers below 10^4.
- Significant errors occurred at higher Rayleigh numbers due to light ray bending from refraction.
Conclusions:
- Differential interferometers are potentially more accurate than Mach-Zehnder interferometers for measuring heat transfer coefficients.
- Refraction poses a significant challenge at higher Rayleigh numbers, limiting accuracy in interferometric measurements.
- Further research may be needed to mitigate refraction effects in interferometric heat transfer studies.
Related Concept Videos
01:15Distance Corrections
To achieve precise distance measurements, especially in surveying and construction, certain corrections must be applied to account for potential sources of error like the standardization errors, temperature variations, and slope adjustments.Standardization error emerges when measurement equipment undergoes changes, such as wear, repairs, or weather impacts. To address this, surveyors compare the equipment’s readings to a standard. This process identifies any deviation that might lead to...
01:04Random Error
Random or indeterminate errors originate from various uncontrollable variables, such as variations in environmental conditions, instrument imperfections, or the inherent variability of the phenomena being measured. Usually, these errors cannot be predicted, estimated, or characterized because their direction and magnitude often vary in magnitude and direction even during consecutive measurements. As a result, they are difficult to eliminate. However, the aggregate effect of these errors can be...
01:20Random and Systematic Errors
Scientists always try their best to record measurements with the utmost accuracy and precision. However, sometimes errors do occur. These errors can be random or systematic. Random errors are observed due to the inconsistency or fluctuation in the measurement process, or variations in the quantity itself that is being measured. Such errors fluctuate from being greater than or less than the true value in repeated measurements. Consider a scientist measuring the length of an earthworm using a...
01:20Conduction, Convection and Radiation: Problem Solving
There are three methods by which heat transfer can take place: conduction, convection, and radiation. Each method has unique and interesting characteristics, but all three have two things in common: they transfer heat solely because of a temperature difference; and the greater the temperature difference, the faster the heat transfer.
In order to solve a problem related to heat transfer, first of all, the situation needs to be examined to determine the type of heat transfer involved. This could...
In order to solve a problem related to heat transfer, first of all, the situation needs to be examined to determine the type of heat transfer involved. This could...
01:12Types of Errors: Detection and Minimization
Error is the deviation of the obtained result from the true, expected value or the estimated central value. Errors are expressed in absolute or relative terms.
Absolute error in a measurement is the numerical difference from the true or central value. Relative error is the ratio between absolute error and the true or central value, expressed as a percentage.
Errors can be classified by source, magnitude, and sign. There are three types of errors: systematic, random, and gross.
Systematic or...
Absolute error in a measurement is the numerical difference from the true or central value. Relative error is the ratio between absolute error and the true or central value, expressed as a percentage.
Errors can be classified by source, magnitude, and sign. There are three types of errors: systematic, random, and gross.
Systematic or...
03:37Uncertainty in Measurement: Accuracy and Precision
Scientists typically make repeated measurements of a quantity to ensure the quality of their findings and to evaluate both the precision and the accuracy of their results. Measurements are said to be precise if they yield very similar results when repeated in the same manner. A measurement is considered accurate if it yields a result that is very close to the true or the accepted value. Precise values agree with each other; accurate values agree with a true value.