Mechanical Engineering as a Discipline

Introduction to Mechanical Engineering

Mechanical Engineering is a discipline concerned with the application of knowledge in solving real-world problems. The study of calibration techniques is considered one of the most crucial topics in the field of engineering as it links accuracy and quality in instruments, thus providing an output with an acceptable amount of error. Calibration is the process of configuring an instrument to provide a result for a sample within an acceptable range. Eliminating or minimizing factors that cause inaccurate measurements is a fundamental aspect of instrumentation design (What is Calibration?). Understanding these principles is essential for engineers who strive to ensure that their tools and measurements are reliable and precise.

Calibration Techniques and Their Importance

The results obtained from calibration help formulate a relationship between the known values and the values obtained with the use of the measuring technique, thus providing a more accurate output. Calibration is not just about adjusting instruments; it is a scientific process that ensures that measurements are consistent and reliable over time. This level of precision is particularly important in fields such as aerospace and automotive engineering, where even minor errors can lead to significant consequences.

Experimentation: Calibration of a Pressure Gauge

The experiment performed in the lab is based on the calibration of a pressure gauge using a dead weight tester. A deadweight tester is a calibration standard that uses the principle of a pressure balance to calibrate pressure measuring instruments. It uses calibrated weights to apply known pressures to a device under test for a simple and cost-effective solution that covers a wide range of pressure calibrations (Deadweight Testers). This method is preferred due to its simplicity and the high degree of accuracy it can achieve.

Principle of Operation

A dead weight tester works on the principle of Pascal’s law which states that “In a fluid at rest in a closed container, a pressure change in one part is transmitted without loss to every portion of the fluid and to the walls of the container” (Pascal's principle). A dead weight tester consists of a pumping piston with a screw that presses it into the reservoir containing a fluid oil, a primary piston that carries the dead weight, W, and the pressure gauge or transducer to be calibrated (How a Dead Weight Tester Works). The primary piston is then loaded with a certain amount of weight W to finalize the desired calibration pressure. It is also noted that the pumping piston pressurizes the whole system by allowing more fluid into the cylinder. This setup ensures that the applied pressure is both measurable and replicable, making it an ideal choice for laboratory settings.

Application: The Bourdon Gauge

In this experiment, the Bourdon Gauge is connected to a dead weight tester. It contains a clear dial through which the mechanism is observed. The Bourdon pressure gauge operates on the principle that, when pressurized, a flattened tube tends to straighten or regain its circular form in cross-section. The Bourdon tube comes in C, helical, and spiral shapes—although most gauges employ the C shape (Flow Control Network). One end of the Bourdon tube is held tightly to introduce pressure while the other end, which is linked to a dial and pointer, is enabled to move freely. Understanding the mechanics of the Bourdon gauge is crucial for engineers as it is widely used in various industries due to its reliability and accuracy.

References

What is Calibration? (n.d.). Retrieved from [source URL]

Deadweight Testers. (n.d.). Retrieved from [source URL]

Pascal's principle. (n.d.). Retrieved from [source URL]

How a Dead Weight Tester Works. (n.d.). Retrieved from [source URL]

Flow Control Network. (n.d.). Retrieved from [source URL]