A dial indicator, as a commonly used precision measuring tool, the accuracy of its measuring rod directly affects
the reliability of the measurement results. So, does the measuring rod of a dial indicator need to be calibrated?
The answer is yes. This article will deeply analyze the importance of dial indicator measuring rod calibration,
and introduce relevant standards and specifications to help you better understand and apply the dial indicator.
I. Why is it necessary to calibrate the measuring rod of a micrometer?
1. To ensure measurement accuracy: The measuring rod is an essential component of a indicator,
and its accuracy directly affects the measurement accuracy of the micrometer. Even minor wear or deformation
can lead to measurement errors, thereby affecting the reliability of the measurement results.
Therefore, regular calibration of the measuring rod is crucial for ensuring measurement accuracy.
2. To comply with quality management system requirements: Many quality management systems,
such as ISO 9001, require the regular calibration of measuring equipment to ensure the traceability and reliability
of measurement results. Calibrating the measuring rod is an important step in meeting these quality management
system requirements.
II. Calibration Standards for Measuring Rods of Micrometers
1. National and International Standards: The calibration of the measuring rods of micrometers needs to comply
with relevant national and international standards, such as JJG 30-2012 "Calibration Procedures for Indicators
and Micrometer Gauges". These standards specify the calibration methods, calibration cycles, and allowable error
ranges for the measuring rods of micrometers.
2. Manufacturer's advice: In addition to national and international standards, one should also refer to the manufacturer's
recommendations to understand the specific calibration methods and cycles for the measuring rods.
III. Calibration Method for the Measuring Rod of the Micrometer
1. Using standard blocks: Standard blocks are block-shaped objects with precise dimensions,
which can be used to calibrate the accuracy of the measuring rod of the micrometer. Place the measuring rod
on the standard block, read the indication of the micrometer, and compare it with the actual size of the standard block
to determine the error of the measuring rod.
2. Using a three-coordinate measuring machine: A three-coordinate measuring machine is a highly precise measuring
device that can also be used to calibrate the measuring rod of a dial indicator. Fix the measuring rod on the
three-coordinate measuring machine, then use the probe to measure the size and shape of the measuring rod,
and you can determine the error of the measuring rod.
IV. Calibration cycle of the measuring rod of the micrometer
1. Frequency of use: The calibration cycle of the measuring rod depends on its usage frequency.
The higher the usage frequency, the shorter the calibration cycle should be.
2. Environmental conditions: Harsh environmental conditions, such as high temperature, high humidity, and dust,
will accelerate the wear and deformation of the measuring rod. Therefore, for measuring rods used in harsh
environments, calibration should be performed more frequently.
3. Accuracy requirements: For measurement tasks with high precision requirements, calibration should be
carried out more frequently.
V. Notes
1. Select a suitable calibration institution: Choose a qualified calibration institution for calibration to ensure
the reliability and traceability of the calibration results.
2. Properly store the measuring rod: When not in use, the measuring rod should be properly stored to prevent
it from being bumped, scratched or corroded.
