The dial bore gauge is a precise measuring tool used to measure the inner diameter of a hole. Choosing the appropriate
length is crucial for measurement accuracy and operational efficiency. This article will analyze the significance of
selecting the length of the dial bore gauge and based on practical application scenarios, provide purchasing suggestions.
I. Why is it necessary to select the appropriate length of the dial bore gauge?
1. Measurement range: The measurement range of the internal diameter micrometer is directly related to its length.
Choosing a micrometer that is too short may prevent it from reaching the bottom of the measured hole,
resulting in inaccurate measurement results; while a micrometer that is too long will increase the operational
difficulty and even damage the measured workpiece.
2. Measurement Accuracy: An appropriate length ensures that the measuring contact point can make full
contact with the wall of the measured hole, thereby improving the measurement accuracy. Length that is too long
or too short will affect the contact area and contact pressure, thus impacting the reliability of the measurement results.
3. Utilization efficiency: Choosing an appropriate length can enhance the measurement efficiency. An overly long gauge
requires more time for adjustment and operation, while an overly short micrometer necessitates multiple
measurements to cover the entire measurement range, thereby reducing the overall efficiency.
II. Basic Principles for Selecting the Length of the Inner Diameter Gauge
1. Select based on the depth of the measured hole: The measuring rod length of the inner diameter micrometer
should be slightly longer than the depth of the measured hole to ensure that the measuring contact can reach
the bottom of the hole.
2. Select based on the diameter of the measured hole: For large-diameter holes, a longer bore gauge should
be chosen to ensure sufficient measurement range; for small-diameter holes, a shorter micrometer can be selected.
3. Select based on measurement accuracy requirements: If high measurement accuracy is required,
it is recommended to choose a dial indicator with an appropriate length and a stable structure to minimize
measurement errors.
III. Length Selection Suggestions for Different Application Scenarios
1. Measuring the inner diameter of small parts: You can choose a dial indicator with a measurement range of 0-25mm
and a relatively short length, such as a measuring rod with a length of 50mm or 75mm.
2. Measuring the inner diameter of large parts, such as engine cylinder blocks: It is necessary to select a dial indicator
with a wider measurement range and a longer measuring rod length, such as 100mm, 150mm or even longer.
The measurement range is usually between 50 and 150mm, or even larger.
3. Measuring the inner diameter of deep holes: It is necessary to select an inner diameter micrometer with an extended
rod to ensure that it can reach the bottom of the hole. The measurement range and length should be determined
based on the actual depth of the hole, such as 200mm, 300mm or even longer.
IV. How to determine the actual measurement range of the dial bore gauge?
1. Refer to the product specification: The specification of the internal diameter micrometer will indicate its
measurement range, length and other parameters.
2. Consult the manufacturer or dealer: If you are unsure about the parameters in the product specification,
you can contact the manufacturer or dealer for a more detailed explanation and advice.
3. Actual Measurement: Before conducting the actual measurement, standard gauge blocks or other known-sized
workpieces can be used for calibration to verify the accuracy and measurement range of the internal
diameter micrometer.
V. Usage Notes for Dial Bore Gauge
1. Zeroing is required before use: Before each use, the inner diameter micrometer must be zeroed to ensure
the accuracy of the measurement results.
2. Maintain stability during measurement: During the measurement process, it is necessary to keep the internal diameter
gauge stable to avoid any shaking or tilting, as this could affect the measurement results.
3. Regular maintenance and upkeep: Regularly clean the internal diameter gauge and perform necessary maintenance
and upkeep to extend its service life.
