Calipers, as a commonly used precision measuring tool, require highly stable measurement results. However,
sometimes we encounter situations where the measured dimensions vary each time the caliper is clamped,
which undoubtedly affects work accuracy. This article will conduct an in-depth analysis of the causes behind this
phenomenon, covering aspects such as the structure of calipers, usage methods, and maintenance practices.
Additionally, it will provide corresponding solutions to help users operate calipers more effectively.
I. The Influence of Caliper Structure on Measurement Results
1. The caliper is mainly composed of the main scale, the vernier, the measuring claws, etc. If these components
are worn, deformed, or loose, it will directly affect the accuracy and stability of the measurement,
resulting in inconsistent dimensions after clamping.
2. For instance, if the surface of the measuring claw is rough or damaged, it will cause the contact surface with the
measured workpiece to be unstable, thereby affecting the measurement results. Similarly, if the scale lines on
the vernier are unclear or the scale of the main ruler is inaccurate, it will also lead to reading errors.
3. Moreover, the locking mechanism of the caliper is also of great significance. If the locking force is insufficient
or there are problems with the locking mechanism itself, it will cause the caliper to experience slight displacement
during the measurement process, resulting in deviations in the dimensions after each locking.
II. The Impact of Caliper Usage Methods on Measurement Results
1. The correct usage method is the key to ensuring the accuracy of measurement results. Many people,
when using calipers, often apply excessive force or too little force, which will affect the measurement results.
2. Applying excessive force may cause the caliper to deform or damage the measured workpiece,
while applying too little force will result in an insufficiently tight contact between the caliper and the workpiece,
there by affecting the stability of the measurement. The ideal force should be just enough to ensure a tight contact
between the caliper and the workpiece without causing deformation or damage.
3. Additionally, when reading the measurement results, ensure that your line of sight is perpendicular to the scale
line to avoid parallax errors. At the same time, select the appropriate measuring jaws based on the shape
and size of the measured workpiece. For example, when measuring the inner diameter, use the inner measuring jaws;
when measuring the outer diameter, use the outer measuring jaws.
III. Maintenance and Care of Calipers
1. Regular maintenance is crucial for ensuring the long-term stable operation of the caliper. After use, the caliper should
be wiped clean and coated with anti-rust oil to prevent rusting. When storing, it should be avoided from colliding with
other hard objects to prevent damage.
2. Regularly inspect all components of the caliper, such as the measuring claws, the scale, and the locking
mechanism, to check for any signs of wear, deformation or looseness. If any problems are found, they should
be promptly repaired or replaced.
3. For some high-precision calipers, it is recommended to conduct regular calibration to ensure their measurement
accuracy. Calibration can be carried out using standard block gauges, or it can be sent to a professional metrology
institution for testing.
IV. Impact of Environmental Factors on Measurement Results
1. Changes in temperature will cause the caliper to expand and contract due to heat and cold,
thereby affecting the measurement results. Therefore, when conducting precise measurements, efforts should
be made to maintain a stable environmental temperature.
2. Moreover, dust, oil stains, etc. can also affect the measurement accuracy of the caliper. Therefore,
before measurement, the caliper and the object being measured should be cleaned thoroughly.
3. Strong magnetic fields can also affect the measurement results of calipers, especially those of electronic calipers.
Therefore, calipers should not be used in environments with strong magnetic fields.
V. Solution
1. Regarding the problems of the caliper itself, it can be repaired or replaced. For instance, if the measuring claws
are severely worn, new measuring claws can be replaced; if the locking mechanism is loose,
it can be tightened or replaced.
2. Regarding the issue of usage methods, more training is needed to standardize the operation procedures.
For instance, it is necessary to teach the operators how to use the caliper correctly, how to control the force,
and how to avoid parallax.
3. Strengthen maintenance and upkeep, and conduct regular inspections and cleaning of the caliper.
This can effectively extend the service life of the caliper and ensure its measurement accuracy.
