What is the error of the micrometer zero position?

Of course, it is a systematic error.

There are the following ways:

1) Generally, the adjustment of non-zero is very simple: use the built-in "hook key" to directly pull the ruler body to make it to zero.

2) When the deviation is large, remove the movable sleeve ruler (it can be screwed out by rotating it backwards), then unscrew out the back ratchet screw, take out the pawl, etc., and then loosen the screw used to fix the pawl (loosen it for one or two turns), use the sleeve to make a transition (top to the bottom of the seat), knock hard, and use the measuring screw and the sleeve ruler away (it is connected by taper). In this way, turn the measuring screw back to the main ruler, hold it tightly, and then put in the sleeve ruler to align it with the zero position, press it lightly and then twist it out and press it tightly. (Note:.)

If the main ruler deviates from the ruler body, it can be pressed back, and when it is found that the sleeve ruler is put back into the main ruler and the zero position is too far away, the taper connection seat behind the sleeve ruler can be directly punched out or driven in to adjust the appropriateness. ）

3) If the gap between the measuring screw and the nut of the main ruler is too large, the lock nut outside can be directly adjusted to a suitable state with a "hook key".

4) The adjusted ruler should be calibrated with the standard school block, if it is a local wear of the screw that causes a deviation in a certain section of the measurement, it can only be scrapped. The above method of adjustment, hope!

Whether the deviation value of the outer diameter micrometer to the zero position is added or subtracted, it should be determined according to the value of the deviation from the zero position. If the zero deviation value is positive, the measured value should be subtracted from the deviation value; If the zero deviation value is negative, this deviation value should be added to the measured value of the branch file. If the micrometer error exceeds it, it is reduced, that is to say, the value of the measurement of the material containing chaos is reduced.

When using a micrometer, it is necessary to check whether its zero position is calibrated, so first loosen the locking device and remove the oil stain, especially the contact surface between the anvil and the micrometer screw should be cleaned. Check whether the end face of the micrometer cylinder coincides with the zero scale line on the fixed sleeve, if it does not coincide, the knob should be rotated first until the screw is close to the anvil, rotate the force measuring device, when the screw is just in contact with the anvil, a click sound will be heard, and then stop rotating. If the two zero lines still do not coincide (the sign of the two zero lines overlapping is:

The end face of the micrometer cylinder coincides with the zero line of the fixed scale, and the zero line of the movable scale coincides with the horizontal horizontal line of the fixed scale), the small screw on the fixed sleeve can be loosened, and the position of the sleeve is adjusted with a special wrench to align the two zero lines, and then the small screw is tightened. The zeroing method of micrometers produced by different manufacturers is different, and here is only one of the zeroing methods.

Reading method: read the scale value of the fixed sleeve on the left with the reference line of the differential sleeve, and then read the scale aligned with the reference line on the scale line of the differential sleeve with the reference line of the fixed sleeve, which is the scale value of the differential sleeve, and add the scale value of the fixed sleeve and the scale value of the differential sleeve to the measured value.

How long has your ruler been used, which manufacturer has produced it, and whether you often measure 15, 21, 25.

The micrometer screw needs to be repaired.

The micrometer indication error is a comprehensive index that reflects the accuracy of the micrometer and is a comprehensive reflection of various defects. In the measurement and testing work, the flatness of the micrometer measuring surface, the parallelism of the two measuring surfaces, the axial channeling and radial swing of the micrometer screw, the measuring force is too large or too small, the inaccurate engraving line and various defects in the structure will cause the indication error to be unqualified.

If the problem of deviation of the indication value cannot be solved after eliminating the above faults according to the order of micrometer investigation, then the cause of the micrometer indication error is the wear of the micrometer screw, and the micrometer screw needs to be repaired.

The micrometer is not accurate, how to adjust it? The deviation is greater than 30s.

Hello! First of all, it is necessary to look at the reason for the deviation of the micrometer: if there is debris on the measuring surface, the measuring surface should be cleaned first.

If the measuring surface of the micrometer is worn, the measuring surface should be ground first, and then corrected after qualification. If the threaded rod is worn, it is recommended to replace it directly. If none of the above reasons have hit the state, but there is a deviation in the zero position of the micrometer, you can loosen the fastening screws on the fixing sleeve with a small screwdriver, and make corrections to the zero position with a good zero position under the dust inspection of the measuring block.

Deviation =. Error: There will always be some discrepancy between the measured value and the true value, and this difference is called error.

Causes of errors: inaccurate measurement tools, imperfect measurement methods, and inadequate observation. The method of reducing the error is to reduce the error caused by the large or small estimate by averaging the average value of multiple measurements.

Note: The number of digits of the average should be consistent with the measurements. In the case of multiple measurements, each time the measurement is taken from a different starting point of the scale, which can reduce the error caused by the possible unevenness of the scale of the scale.

Millimeter scale.

Reading 0,5mm

4,5mm when the object is pointing to the left in the middle of the two scale values.

The true value of the reading mm is also in this range, and the difference between the reading and the true value is the most.

When the reading mm is biased to the right, the true value is also in this range, and the difference between the reading and the true value is the most.

So the margin of error is.

thanks

The exact meaning of the error limit is the maximum possible error under normal measurement conditions. The so-called normal conditions refer to the measurement method is in accordance with the standard, the error of the measuring tool is within the specified range, the surveyor is well-trained, has the ability to distinguish normal readings, and other factors such as ambient temperature are within the specified range, etc., and there is no fault in the measurement. When this condition is satisfied, the maximum possible error is usually considered to be half of the minimum graduation value, which is the case with the millimeter scale, which is the conclusion reached by previous statistical analysis based on a large amount of data.

The error limit includes the error of the measuring tool itself, the estimation error caused by the limitation of the normal human eye's resolution ability (there are estimation errors at both ends when measuring the length of the millimeter ruler), and the error caused by other accidental factors (not exceeding the specified range).

If you have any questions, please feel free to ask.