The granite surface plate is manufactured from high-quality natural granite that has undergone millions of years of natural aging. After precision machining and manual grinding, it becomes a reliable precision measuring platform. With its fine-grained texture, high hardness, excellent wear resistance, and outstanding stability, it is widely used as a reference base in machining, metrology, and laboratory testing.
Because of its unique structural properties, the granite surface plate is an indispensable tool in height and dimensional measurement. But how exactly is height measured on such a platform? Let's explore.
Instruments Used for Height Measurement
When measuring the height of a workpiece on a granite surface plate, different instruments may be applied depending on accuracy requirements:
Vernier Height Gauge
Structure: A rigid base with a vertical scale, a movable slider (vernier), and a fine-adjustment mechanism.
Precision: Typically offers a reading accuracy of 0.02–0.03 mm.
Application: Commonly used for general height measurement of parts placed on a granite surface plate.
Dial Indicator (Dial Gauge)
Structure: Resembles a small clock face with one or two hands.
Precision: Graduation of 0.01 mm or 0.02 mm, with a measuring range around 5 mm.
Usage: Not strictly for height measurement, but widely applied to check form and positional tolerances of parts.
Micrometer Indicator (Dial Test Indicator / Micron Dial Gauge)
Precision: Extremely high, with readings down to 0.001 mm.
Range: Small measuring range, generally within 1–2 mm.
Application: Suitable for detecting very small variations in part height on the granite plate.
Steps for Accurate Height Measurement
Place the workpiece steadily on the granite surface plate to ensure no external vibrations or dirt affect the result.
Select the appropriate measuring instrument depending on the required tolerance.
Adjust the instrument's base to contact the granite surface plate securely.
Take readings by moving the slider (vernier scale) or observing the pointer (dial gauge).
For high-precision applications, repeat the measurement multiple times to eliminate random error.
Why Granite Surface Plates?
Non-rusting & corrosion resistant: No need for oiling.
Non-magnetic: Ensures smooth, friction-free movement of measuring instruments.
Stable & stress-free: Natural aging eliminates internal stress, ensuring long-term accuracy.
High wear resistance: Extends service life in heavy-duty measurement tasks.
In conclusion, the granite surface plate combined with vernier height gauges, dial indicators, or micrometer indicators forms a reliable system for high-precision height measurement. This makes it indispensable in machining workshops, quality control departments, and laboratories.