While measuring surface texture, the part of the profilometer that makes contact with the workpiece surface is _____.

Explanation:

Profilometer and Surface Texture Measurement

Definition: A profilometer is an instrument used to measure the surface texture (roughness) of a workpiece. This measurement is crucial in various manufacturing processes, as it can affect the functionality, appearance, and performance of the finished product. The profilometer provides quantitative data on the surface profile, which can be analyzed to ensure that the workpiece meets the required specifications.

Working Principle: The profilometer operates by tracing the surface of the workpiece with a contact or non-contact method. The contact method, which is the focus of this explanation, involves a finely pointed stylus that physically touches the surface. As the stylus moves across the surface, it detects the peaks and valleys of the texture, converting this information into an electrical signal. This signal is then processed to produce a detailed profile of the surface's roughness.

The Stylus: The stylus is a critical component of the contact profilometer. It is typically made of a hard material, such as diamond or tungsten carbide, to ensure durability and precision. The finely pointed stylus has a sharp tip radius, usually in the range of micrometers, which allows it to accurately trace the minute details of the surface texture. The movement of the stylus is controlled by a motorized mechanism, ensuring consistent and precise measurement.

Advantages:

• High Precision: The finely pointed stylus provides high-resolution measurements, making it possible to detect very small surface irregularities.
• Versatility: Profilometers with a stylus can measure a wide range of surface textures, from very smooth to very rough surfaces.
• Detailed Analysis: The data obtained from the profilometer can be used to generate detailed surface profile charts, allowing for thorough analysis and quality control.

Disadvantages:

• Contact Method Limitations: Since the stylus physically touches the surface, it may not be suitable for very delicate or soft materials that could be damaged by the contact.
• Speed: The measurement process can be relatively slow compared to non-contact methods, as the stylus needs to move over the entire surface area.

Applications: Profilometers with a finely pointed stylus are widely used in various industries, including automotive, aerospace, and electronics, where precise surface texture measurement is crucial. They are used for quality control, research and development, and ensuring that components meet strict surface finish standards.

Analysis of Other Options:

Option 1: A motorised mechanism

While a motorized mechanism is a crucial part of the profilometer, it is not the part that directly makes contact with the workpiece surface. The motorized mechanism is responsible for controlling the movement of the stylus or the profilometer over the surface. It ensures that the measurement is carried out consistently and accurately. However, it does not itself engage with the surface for measurement purposes.

Option 3: An electrical pickup

An electrical pickup is not the component that contacts the workpiece surface in a profilometer. Instead, it is likely part of the system that processes the electrical signals generated by the stylus movement. These signals are then used to create a detailed surface profile. The electrical pickup plays a role in signal processing but does not physically touch the surface being measured.

Option 4: A recording unit

The recording unit of a profilometer is responsible for capturing and storing the data obtained from the surface measurement. This unit processes the electrical signals from the stylus and generates the surface profile charts. While it is essential for data analysis and storage, it does not directly interact with the workpiece surface. The recording unit is more involved in the post-measurement phase, handling data rather than measurement.