Which of the following is NOT a feature of pneumatic comparators? 

Explanation:

Pneumatic Comparators

• Pneumatic comparators are precision measuring instruments that use compressed air as the medium to perform dimensional measurements. These comparators are widely used in industrial and manufacturing settings where high precision and non-contact measurement are required. The principle of operation is based on the variation of air pressure or air flow, which is influenced by the dimension of the part being measured.

Presence of hysteresis

• Pneumatic comparators do NOT exhibit hysteresis. Hysteresis refers to the lag between the input and output in a system, often caused by friction, material deformation, or other factors in mechanical systems. Since pneumatic comparators rely on the flow of air and pressure changes to perform measurements, they do not involve mechanical contact or moving parts that could lead to hysteresis. This absence of hysteresis is one of the significant advantages of pneumatic comparators, as it ensures accurate and repeatable measurements without errors caused by mechanical lag.

Hysteresis is typically associated with systems that have elastic or mechanical components, such as springs, levers, or other mechanical arrangements. In the case of pneumatic comparators, the measurement principle is purely based on the flow and pressure of air, making them free from this phenomenon.

Additional InformationOption 1: High range of amplification

• Pneumatic comparators are known for their high range of amplification. They can amplify small dimensional variations significantly, making them highly sensitive and suitable for precision measurement tasks. This feature allows them to detect minute deviations in the dimensions of workpieces, which is essential in quality control processes.

Option 2: Non-contact inspection of work parts

• Pneumatic comparators perform non-contact inspection of work parts. Since the measurement is based on air flow and pressure, there is no need for the comparator to physically touch the workpiece. This non-contact feature is particularly advantageous for inspecting delicate or soft materials, as it prevents damage or deformation during the measurement process.

Option 3: No wearing of parts

• One of the key advantages of pneumatic comparators is the absence of mechanical contact between the instrument and the workpiece. This eliminates wear and tear on the measuring components, ensuring a longer lifespan and consistent performance of the instrument. This feature also reduces maintenance requirements.