Dial indicators–also called dial gauges or dial test indicators, are precision tests and measuring instruments used to measure small linear displacements and deviations with high accuracy. A dial indicator comprises various components, including a dial face, needle or plunger, bezel, stem or spindle, and a clamp or mounting mechanism. These mechanical devices measure different distances in metric or imperial forms in millimetres or less. Dial gauges come in assorted ranges and configurations to meet specific needs in various applications. Some of the main functions of the dial indicators include:
- Alignment: Checking alignment in machines and mechanical components.
- Runout measurement: Determining the concentricity or eccentricity of rotating components.
- Deflection and deformation: Measuring deflection and deformation in structures and materials.
- Quality control: Measuring dimensions and tolerances in manufactured parts.
- Comparative measurements: Comparing the dimensions of different parts against a standard.
How Does a Dial Indicator Work?
The integrated needle on a dial indicator is typically attached to a spring-loaded plunger, which moves in and out as the instrument is adjusted. This movement is translated into a corresponding needle action across the scale, allowing the user to make accurate measurements.
Dial Indicator Popular Types
A dial indicator comes in various types, where the most common types include:
- Plunger Dial Indicator – A plunger dial indicator is the most common type of spring-loaded plunger–moving in and out when it meets the measured surface. The plunger movement is amplified and indicated by a dial with a needle, providing the measurement in both positive and negative directions.
- Lever-Type Dial Test Indicator – Like plunger dial indicators, lever-type dial test indicators also use a spring-loaded plunger for measuring small linear displacements. However, these indicators are typically mounted on a flexible arm or a swivelling mechanism, making them more versatile for measuring hard-to-reach areas and tight spaces.
- Digital Test Indicator – Digital test indicators share similar functionality with traditional dial indicators. However, instead of an analogue dial, they feature an electronic digital display, providing precise digital readings with decimal accuracy.
Choosing the Best Dial Indicators
The best dial indicator for you will depend on your specific application and budget. However, when choosing the best dial indicators, consider the following factors:
- Accuracy – The accuracy of a dial indicator is the most crucial factor to consider. The accuracy is usually measured in thousandths of an inch or millimeters; look for a dial indicator with a high accuracy level.
- Durability – Ascertain a dial indicator’s durability–high-quality materials and sturdy design.
- Resolution – The resolution of the dial indicator is the smallest measurement that the indicator can display. Consider a dial indicator that has a high resolution, especially if you need to measure small distances.
- Range – Choose a dial indicator with a range suitable for your specific application.
- Price – The price of the dial indicator is also a factor to consider. Look for a dial indicator that offers good value for money and fits within your budget.
- Brand Reputation – Brand reputation is also essential. Choose a dial indicator from a brand with a good track record for manufacturing high-quality products, such as Mitutoyo Dial Indicators.
Typical Applications of Dial Indicators
Dial indicators can be used to measure a variety of parameters, including distance, height, depth, and runout. A dial indicator is also often used in conjunction with other measurement tools, such as micrometers and callipers, to provide more comprehensive measurements. They find multiple applications in various scenarios, including:
- Meteorology
- Construction
- Engineering Workshops
- Education and Training
- Quality Control
- Woodworking
- Maintenance and Repair
- Machining and Manufacturing
- Automotive Industry
- Transportation and Railways.
