The reading method of the dial indicator is: first read the tick mark rotated by the small pointer (ie, the millimeter integer), then read the tick mark (that is, the decimal part) rotated by the large pointer, and multiply by 0.01, then add the two, that is, The measured value is obtained.

Dial indicator usage and precautions:

1) It should be fixed on a reliable bracket. Depending on the measurement needs, you can choose a table stand with a platform or a universal watch stand.

2) The dial indicator should be securely clamped to the frame clamp. If it is fastened with the clamping sleeve, the clamping force should not be too large, so as to avoid deformation of the clamping sleeve and jam the measuring rod, it should check whether the movement of the measuring rod is flexible. Do not turn the dial indicator again after tightening.

3) The measuring rod must be perpendicular to the surface of the workpiece to be tested, otherwise a large measurement error will result.

4) When measuring cylindrical workpieces, the axis of the measuring rod should be consistent with the diameter direction of the cylindrical workpiece.

5) Before the measurement, check whether the dial indicator is clamped and does not affect its sensitivity. For this purpose, the repeatability can be checked, that is, the multi-lifting dial indicator is slightly higher than the height of the workpiece, and the measuring rod is lowered to make contact with the workpiece, and the measurement can be performed only when the repeatability is good.

6) During the measurement, gently lift the measuring rod, move the workpiece under the probe, slowly lower the probe to make contact with the workpiece, and forcibly push the workpiece into the probe, and do not allow the sudden drop measurement. Head, so as not to produce instantaneous impact force, bring errors to the measurement. When adjusting the workpiece, the above operation method should also be used. When the probe is in contact with the surface of the workpiece, the measuring rod should have a compression of (0.3~1) mm to ensure a certain initial measuring force.

7) Depending on the shape of the workpiece, various shapes of the probe can be made for measurement: for example, a flat probe can be used to measure a spherical workpiece; a spherical probe can be used to measure a cylindrical or flat surface; a pointed probe or a radius of curvature can be used. Spherical probes measure concave or complex surfaces. When measuring the thickness of a thin workpiece, it must be measured once and for all on both sides, taking the minimum value, so as not to reflect the size correctly due to bending.

8) Do not add oil to the measuring rod to prevent the oil from entering the watch, which affects the flexibility of the transmission mechanism and the movement of the measuring rod.

9) When the dial indicator is not in use, the pole should be in a free state to avoid malfunction of the spring inside the watch.

10) When measuring, do not make the stroke of the measuring rod exceed its measuring range, do not make the meter head suddenly hit the workpiece, and do not use the dial gauge to measure the surface roughness or work with significant unevenness.

The main factors affecting the accuracy of the dial gauge are:

1) The parallelism between the centerline of the rack and the axis of the rod and the error caused by the fit between the rod and the sleeve

2) Error caused by the geometric error of the shaft gear Z1 shaft diameter

3) The error caused by the eccentricity of the scale center of the dial and the center of the pointer rotation

4) Error caused by uneven spring force measurement