ROK Digital calipers are extremely economical and accurate measuring instruments. They usually have a resolution of 10 µm with an accuracy of 30 to 40 µm. This high performance and cost efficiency is achieved with the use of multiplate capacitive sensors dial caliper.
Capacitive sensors are extremely rugged and simple to build. They are highly linear and immune to mechanical and electronic noise. However, since they rely on capacitance, they are sensitive to liquids. Any liquid that bridges the capacitive plates increases the capacitance. A drop of oil can increase the capacitance by a factor of 80!
Digital calipers can be bought at prices as low as $15 each. They have an LCD read out and a serial output. Considering their usefulness and low price, I have made this web page that puts together some of the information I collected. Many of this information Dial Test Indicators comes from individuals that have posted on the web. These individuals are driven solely by passion but contribute enormously to the advancement of knowledge. Therefore, I believe that it is also my duty to perpetuate knowledge in a similar manner. The earliest vernier caliper has been found in the wreck near the coast. The ship find dates to the 6th century BC. The wooden piece already featured a fixed and a movable jaw.Although rare finds, caliper remained in use by the Greeks and]
The modern vernier caliper, reading to thousandths of an inch, was invented by American Joseph R. Brown in 1851. His Brown and Sharpe company inaugurated true precision manufacture in the United States. It was the first practical tool for exact measurements that could be sold at a price within the reach of ordinary machinists.
Dial calipers manufacturer are comparatively easy to read, especially when seeking exact center by rocking and observing the needle movement. They can be set to 0 at any point for comparisons. They are usually fairly susceptible to shock damage. They are also very prone to getting dirt in the gears, which can cause accuracy problems. Digital calipers switch easily between centimeter and inch systems.They can be set to 0 easily at any point with full count in either direction, and can take measurements even if the display is completely hidden, either by using a “hold” key, or by zeroing the display and closing the jaws, showing the correct measurement, but negative. They can be mechanically and electronically fragile. Most also require batteries, and do not resist coolant well. They are also only moderately shockproof, and can be vulnerable to dirt.
Calipers may read to a resolution of 0.01 mm or 0.0005″, but accuracy may not be better than about ±0.02 mm or 0.001″ for 150 mm (6″) calipers, and worse for longer ones