A depth gauge, a simple yet practical measuring tool, is often used to measure the depth of holes, grooves,
and the height of steps, etc. Then, what is the smallest hole depth that a depth gauge can measure?
This article will delve into the measurement range and usage methods of depth gauges.
I. Measuring Range of Depth Gauges
1. Starting Scale: The measuring range of a depth gauge depends on its starting scale.
Some depth gauges start from zero, while others do not. Depth gauges starting from zero can directly measure
the depth of a hole, while those with a non-zero starting scale require some calculations.
2. Minimum measurable hole depth: For a depth gauge with a starting scale of zero, theoretically, the minimum
measurable depth is zero, which is essentially a flat surface. However, in practice, due to the thickness of
the gauge body and the limitations of reading, the minimum measurable hole depth is usually restricted
by the thickness of the gauge body and the smallest scale.
3. Tips for Measuring Deep Holes: For deeper holes, an extension rod can be used to expand the measuring range
of the depth gauge. Some depth gauges come with retractable extension rods, which are very convenient to use.
II. Usage Method of the Depth Gauge
1. Vertical placement: Place the depth gauge vertically within the measured hole, ensuring that the gauge
body is in close contact with the hole wall.
2. Reading the scale: Read the scale value on the ruler, which represents the depth of the hole.
3. When the starting scale is not zero: If the starting scale of the depth gauge is not zero, the read scale value
needs to be subtracted from the starting scale value in order to obtain the actual depth of the hole.
4. Utilizing auxiliary tools: For some complex-shaped holes, auxiliary tools such as magnetic bases
and universal supports can be used to fix the depth gauge, making the measurement process more convenient.
III. Types of Depth Measuring Instruments
1. Micrometer Depth Gauge: The micrometer depth gauge offers more precise measurements.
Its smallest scale is usually 0.02mm or 0.05mm.
2. Digital Depth Gauge: The digital depth gauge can directly display the measurement result,
making it more convenient and efficient to use.
3. Depth gauge with display: The readings of the depth gauge with display are clearer and easier to read.
IV. Factors Affecting Measurement Accuracy
1. Accuracy of the measuring instrument: The accuracy of the depth gauge itself will affect the measurement results.
2. Reading error: Errors may occur when reading the scale.
3. Shape of the hole wall: If the hole wall is irregular, it will affect the measurement results.
V. Notes
1. Select the appropriate depth gauge: Choose the appropriate depth gauge based on the size
and precision requirements of the measured hole.
2. Pay attention to safety: When using the depth gauge, be careful to ensure your safety and avoid causing any scratches.
3. Regular Maintenance: Regular cleaning and maintenance of the depth gauge can extend its service life.
