Metrology Interview Questions and Answers For Mechanical Student
In this post Measurement / Metrology Engineering related interview questions with answers are shared which may frequently asked at the time of interview ,viva or oral examination specially For interview Quality Inspector .
1. What are measurement standards?
ans. Standards are objects of known size, quantity, roughness, etc. These standards are used to calibrate and verify measuring instruments. As a result, measured values are more accurate.
2. What effect will temperature variation have on precision measurements?
ans. Temperature control during measurement is important because as materials are heated they expand. Each material expands at a different rate. This leads to distortion of parts and measuring devices that results in measurement errors.
3. How can a vernier scale provide higher accuracy?
ans. A vernier scale uses a second elongated scale to interpolate values on a major scale.
4. What are dimensional tolerances, and what are their primary uses?
ans. Dimensional tolerances specify the amount a dimension may vary about a target value. These are supplied by a designer to ensure the correct function of a device. If these tolerances are controlled the final product will work as planned.
5. Why is an allowance different from a tolerance?
ans. A tolerance is the amount a single dimension can vary. An allowance is an intentional difference between two dimensions to allow for press fits, running fits, etc.
6. What are fits?
ans. There are standard for different types of fits (e.g. press fit, running clearance). These specify the allowance of two parts, so that they may be made separately and then joined (mated) in an assembly.
7. What is the difference between precision and accuracy?
ans. Precision suggests a limit of technology, accuracy is the ability to achieve a value consistently. These are often interchanged because we are usually concerned with the accuracy when producing precision parts.
8. Why are different grades of gauge blocks used?
ans. There are different quality levels for gages blocks. The poorest sets are workshop grade and are more accurate than most machine tools. The best sets are very accurate, and must be kept in tightly controlled conditions. The bast sets are used for calibrating others.
9. How are a ring gauge and a plug gauge different?
ans. A plug gage goes into a hole, a ring gage surrounds a dimension.
10. Why is a micrometer used for precise measurement of components in mechanical engineering?
ans : Digital calipers are pretty accurate, but if you need precision, a micrometer is the way to go. Some things need to be measured in 1/10000ths of an inch (e.g. high pressure hydraulic pump pistons) and a digital caliper just won’t do that. That said, I use calipers all the time and use a mic when I need to.
11. How are pressure gauges specified?
ans : There are a number of things to take into account while specifying the right pressure gauge for your application. This goes from choosing the right measuring range, choosing the diameter of the dial, to preventing the pressure gauge from being subject to vibrations and even more of this kind of choices.
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