Positive zero error in screw gauge

A typical micrometer screw gauge The above image shows a typical micrometer screw gauge and how to read it. Steps: • To obtain the first part of the measurement: Look at the image above, you will see a number 5 to the immediate left of the thimble. This means 5.0 mm. Notice that there is an extra line below the datum line, this represents an additional 0.5 mm. So the first part of the measurement is $5.0 + 0.5 = 5.5$ mm. • To obtain the second part of the measurement: Look at the image above, the number 28 on the rotating vernier scale coincides with the datum line on the sleeve. Hence, 0.28 mm is the second part of the measurement. You just have to add the first part and second part of the measurement to obtain the micrometer reading: $5.5 + 0.28 = 5.78$ mm. To ensure that you understand the steps above, here’s one more example: First part of the measurement: 2.5 mm Second part of the measurement: 0.38 mm Final measurement: 2.88 mm Compensating For Zero Error In a nutshell Use the following formula: $$\text$ can be either negative (the “0” marking on the thimble is above the datum line) or positive ( the “0” marking on the thimble is below the datum line ) Explanation Now, we shall try with zero error. If you are not familiar on how to handle zero error for micrometer screw gauge, I suggest that you read up on The reading on the bottom is the measurement obtained and the reading at the top is the zero error. Find the actual measurement. (Meaning: get rid of the zero error...

Hi, I have a question to ask. On my notes that my teacher gave me, he said that there are some errors in the notes. He had not responded to me which are the errors yet but he said about zero errors in vernier calipers and micrometer screw gauge. The question is: On my notes, it says that: Vernier Calipers 1. Positive zero error occurs when the ‘0’ marking of the vernier scale appears after the ‘0’ marking of the main scale. The error is +x cm. To correct the reading, we subtract the error from the measurement. 2. Negative zero error occurs when the ‘0’ marking of the vernier scale appears before the ‘0’ marking of the main scale. The error is -(0.1-y) cm. To correct the reading, we subtract the error from the measurement. Micrometer Screw Gauge 1. Positive zero error occurs when the ‘0’ marking of the thimble scale is below the horizontal reference line of the main scale. The error is +x mm. To correct the reading, we subtract the error from the measurement. 2. Negative zero error occurs when the ‘0’ marking of the thimble scale is below the horizontal reference line of the main scale. The error is -(0.1-y) mm. To correct the reading, we subtract the error from the measurement. The problem lies in the sentence: To correct the reading, we subtract/add the error from the measurement. About the subtracts in all the sentence, may I know which one should be add instead of subtract? Thanks! :) When talking about errors it is important to use a clear language. The word "error" ca...

On bringing the flat end of the screw in contact with the stud, the zero mark of the circular scale coincides with the zero mark on the base line of the main scale, the instrument is said to be free from zero error. Otherwise, an error is said to be there. This can be both positive and negative zero error. This must be accounted while making the calculations.