Measuring the output of strain gauges

TL;DR

The video discusses experiments with strain gauges, showcasing resistance changes and circuit improvements for better readings.

Transcript

welcome everyone in this video i'm going to continue the experiments with strain gauges so in the previous video i made this bar with this strain gauge in the middle of it and what i did i basically showed you how to install this strain gauge by using some adhesives and i also showed you how to solder these wires to the tabs on the strain gauge and... Read More

Key Insights

• 💱 Strain gauges are crucial for measuring changes in material resistance when they experience deformation, facilitating stress analysis.
• ⚡ The video emphasizes the need for improved circuit designs to capture the minor voltage changes associated with strain measurements accurately.
• 🌉 Effective measurement requires consideration of resistance-to-voltage conversion methods, such as utilizing Wheatstone bridges.
• 🉐 The integration of programmable gain amplifiers can significantly enhance the sensitivity of measurements, addressing the shortcomings of traditional amplification techniques.
• 🏂 Noise reduction strategies are critical to maintaining the accuracy of readings, encouraging the shift toward using printed circuit boards.
• 🌱 The author plans to explore the potential of full or half bridges to incorporate multiple strain gauges, enhancing measurement capabilities.
• 👻 The adaptability of the circuit design will allow for adjustments tailored to specific experimental conditions, including temperature sensitivity.

Questions & Answers

Q: What is the main purpose of the strain gauge experiment shown in the video?

The primary goal of the strain gauge experiment is to measure the resistance changes in a bar when subjected to tensile and compressive forces. By bending the bar, the resistance of the strain gauge changes, which is a critical aspect to understanding material properties and stress analysis.

Q: What problems were encountered during the initial experiments with the strain gauge?

The initial experiments revealed that the change in resistance due to deformation was minimal, only about one ohm. Additionally, measuring resistance directly in electronic applications can be impractical, prompting the need for alternative methods like voltage measurement through circuits such as Wheatstone bridges.

Q: How does the Wheatstone bridge function in the context of the experiment?

The Wheatstone bridge is used to measure very small changes in voltage caused by resistance changes in the strain gauge. It consists of four resistors, where the strain gauge acts as one resistor, allowing for precise voltage readings when the bridge is balanced or unbalanced due to applied strain.

Q: Why is the author switching to using the ADS 1256 with the Wheatstone bridge?

The author is switching to the ADS 1256 to take advantage of its built-in programmable gain amplifier, which can enhance the voltage levels measured from the strain gauge. This shift is intended to improve measurement sensitivity and reduce noise compared to using traditional op-amps and additional circuitry.

Q: What is the significance of measuring output voltage changes in microvolts during the experiments?

Measuring changes in output voltage in microvolts highlights the sensitivity required to capture the small deformations detected by the strain gauges. This small scale of change necessitates precise measurement techniques to ensure that the readings are accurate and meaningful for analysis.

Q: How does the author plan to address noise issues in future experiments?

The author aims to minimize noise by transitioning from a breadboard setup to a PCB, which will reduce wire lengths and interference from ambient noise. Additionally, incorporating capacitors for filtering purposes will help enhance signal stability and measurement precision.

Q: What future enhancements does the author consider for the strain gauge circuit?

Future enhancements may include redesigning the circuit for better stability using a customized voltage regulator and Wheatstone bridge setup, allowing for the possibility of expanding the system to measure multiple strain gauges. This could improve flexibility in experiments and provide better compensation for factors like temperature variations.

Q: What feedback does the author encourage from viewers?

The author invites viewers to share questions, ideas, or feedback in the comments section, emphasizing the importance of community input and discussion to deepen understanding and enhance future experiments related to strain gauge technology.

Summary & Key Takeaways

• The video continues a series on strain gauges, demonstrating how to install and use them to measure resistance changes due to deformation.

• It explains the limitations of current setups, including insufficient resistance change and complexity in measuring resistance directly.

• A new circuit design utilizing a built-in amplifier is proposed to enhance sensitivity and accuracy in future strain gauge measurements.