Why micrometer screw gauge is accurate?
The micrometer screw gauge. If a more accurate measurement is needed a micrometer screw gauge can be used. This normally has accuracy of 0.01 mm and is used to measure objects no more than a few millimetres across.
In general, a micrometer will measure to the nearest 0.01 mm while a vernier caliper will measure to the nearest 0.1 mm. This makes the micrometer the more precise of the two measuring devices. You might understandably think that it would be more accurate to use the micrometer than the calipers.
- So, a meterstick can generally be used to measure lengths to an accuracy of 0.5 mm. In general, a micrometer will measure to the nearest 0.01 mm while a vernier caliper will measure to the nearest 0.1 mm. This makes the micrometer the more precise of the two measuring devices.
- The quoted uncertainty of a length measurement using a meter rule is therefore ±1 mm. In the case of instruments that do not have scales, for example the digital readout of the top balance, the uncertainty is still half of the smallest division (0.0005 g for the balances which read to the nearest milligram).
- The triple beam balance is used to measure masses very precisely; the reading error is 0.05 gram. With the pan empty, move the three sliders on the three beams to their leftmost positions, so that the balance reads zero.
The vernier scales may include metric measurements on the lower part of the scale and inch measurements on the upper, or vice versa, in countries that use inches. Vernier calipers commonly used in industry provide a precision to 0.01 mm (10 micrometres), or one thousandth of an inch.
- Thus, the main parts of a vernier caliper are:
- Internal jaws.
- External jaws.
- Main arm.
- Sliding arm.
- Depth measuring probe.
- Locking Screw.
- The Mitutoyo 506-207 lightweight vernier height gauge has a measurement range of 0 to 200 mm, is precise to 0.02 mm, with + or - 0.03 mm of accuracy, and is suitable for scribing from a vertical base or for measuring small objects.
- A micrometer is a tool used for the precise measurement of very small objects. A micrometer can measure the depth, length and thickness of whatever object fits between its anvil and spindle. It is commonly used in mechanical engineering and machining applications.
Answer: As compare to Vernier calipers, screw gauge is more precise because the least count of Vernier calipers is 0.1 mm and for screw gauge it is 0.01 mm. So, a screw gauge can measure more precisely than a Vernier caliper.
- The least count error is the error associated with the resolution of the instrument. If we use a metre scale for measurement of length, it may have graduations at 1 mm division scale spacing or interval. A Vernier scale on caliper may have a least count of 0.02 mm while a micrometer may have a least count of 0.01 mm.
- The least count error is the error associated with the resolution of the instrument. If we use a metre scale for measurement of length, it may have graduations at 1 mm division scale spacing or interval. A Vernier scale on caliper may have a least countof 0.02 mm while a micrometer have least count of 0.01 mm.
- A vernier scale is a visual aid that allows the user to measure more precisely than could be done unaided when reading a uniformly divided straight or circular measurement scale. It is a subsidiary scale that indicates where the measurement lies in between two of the graduations on the main scale.
Updated: 25th November 2019