Paquímetro analógico - como usar e como fazer a leitura

Summary

This video provides a detailed overview of using a caliper (paquímetro) for dimensional measurements. It explains the construction and features of the instrument, which is made from stainless steel and designed for accuracy and durability. The tutorial covers how to properly use the caliper for external, internal, and depth measurements, and emphasizes the importance of correct positioning to ensure precise readings. The video also demonstrates how to read the main and Vernier scales to obtain accurate measurements, providing a clear step-by-step guide for proper technique and maintenance of the caliper.

Takeaways

• 😀 A caliper (paquímetro) is a widely used instrument for quick and relatively accurate measurements.
• 😀 Calipers are typically made of tempered stainless steel, ensuring long life without oxidation.
• 😀 The Brazilian standard ABNT NBR NM 216:2000 outlines the construction characteristics and metrological requirements of calipers.
• 😀 A universal caliper includes several measuring surfaces: internal, external, depth, and a movable scale for measurement.
• 😀 It is crucial to position the caliper correctly and avoid friction between the part and the measuring surfaces.
• 😀 For external measurements, the fixed measuring surface should be placed at one end of the part, with the movable surface gently touching the other end.
• 😀 For internal measurements, the internal measuring surfaces should be fully inserted and correctly aligned with the part's surfaces.
• 😀 To measure depth, the caliper should be placed correctly on the part, ensuring accurate measurement of depths.
• 😀 When measuring projections or projections, use the appropriate caliper part perpendicularly to the reference surface of the piece.
• 😀 Before taking any measurement, ensure the caliper is fully closed, and the scales' zero points are aligned; misalignment indicates instrument issues.
• 😀 To read measurements, observe the last visible trace on the main scale and add the corresponding value from the micrometer scale. For example, a reading might be 16 mm plus 0.7 mm, giving a total of 16.7 mm.

Q & A

What is the main topic of the video?

The video focuses on the topic of calipers (paquímetros), specifically their use in dimensional metrology for making precise and quick measurements.

What material are calipers typically made of?

Calipers are usually made of tempered stainless steel, ensuring they are durable and resistant to oxidation.

What is the purpose of the Brazilian standard ABNT NBR NM 216 of 2000?

This standard specifies the construction characteristics and metrological requirements for calipers, ensuring their quality and accuracy.

What are the main parts of a universal caliper?

A universal caliper consists of internal measuring surfaces, a fixation screw, a depth measuring rod, a main scale, a movable measuring head, and external measuring surfaces.

How should a caliper be positioned for accurate measurements?

For accurate external measurements, the fixed measuring surface should be placed at one end of the object, while the movable surface should gently touch the other end. Internal measurements should involve inserting the internal surfaces fully and ensuring they are well-aligned with the object's surface.

What is the proper way to measure depth with a caliper?

To measure depth, the caliper should be properly placed on the object, ensuring that the depth rod makes proper contact with the measuring surface to avoid errors.

How do you measure projections (raised areas) with a caliper?

For measuring projections, the caliper should be placed perpendicularly to the reference surface of the object, using the appropriate measuring part designed for projections.

What should you do before taking a measurement with the caliper?

Before measuring, you should close the caliper completely and check the zero point of the scales. If the marks do not align, the instrument may have issues, affecting the measurement accuracy.

How is the measurement read on a caliper with a resolution of 0.1 mm?

To read the measurement, first note the last marked line on the main scale that is aligned with the zero of the Vernier scale. Then, identify the corresponding mark on the Vernier scale. For example, if the last mark on the main scale is 16 mm, and the seventh mark on the Vernier scale is 0.7 mm, the total measurement would be 16 + 0.7 = 16.7 mm.

What should you do if the scales on the caliper are misaligned?

If the scales are misaligned, the caliper may be defective, which could lead to inaccurate measurements. You should ensure the instrument is calibrated and functioning correctly before taking measurements.