Discussion Overview
The discussion revolves around the fine tuning of a cylindrical capacitor used in an airplane fuel gauging probe. Participants explore methods to achieve precise capacitance measurements, particularly focusing on achieving 2nd digit accuracy in the context of varying lengths and diameters of the capacitor tubes.
Discussion Character
- Technical explanation
- Debate/contested
- Experimental/applied
Main Points Raised
- Mike introduces the topic, specifying the dimensions and capacitance range of the cylindrical capacitor used in the fuel gauging probe.
- One participant suggests connecting a variable capacitor in parallel that can be tuned with a screwdriver to achieve the desired fine tuning.
- Another participant questions the types of errors that need to be addressed, including whether they are related to dry capacitance offsets, liquid-dependent non-linearities, or manufacturing variations. They propose using a calibration table stored in non-volatile memory and suggest using a microcontroller or logic device for accurate output data.
- The same participant notes potential non-linearities in capacitance changes during different stages of liquid filling, emphasizing the need for calibration to account for these variations.
- The suggestion to use a variable capacitor is reiterated, with Mike expressing confidence in his ability to implement this solution despite not being an electrical engineer.
Areas of Agreement / Disagreement
Participants present multiple approaches to fine tuning the capacitor, with some advocating for the use of a variable capacitor while others emphasize the importance of calibration and addressing non-linearities. There is no consensus on the best method or the specific errors to be corrected.
Contextual Notes
Participants have not fully defined the types of errors to be tuned out, and there are unresolved questions regarding the measurement and output/display methods for capacitance data. The discussion also reflects varying levels of expertise among participants.
Who May Find This Useful
This discussion may be useful for individuals interested in electrical engineering, particularly those working with capacitive sensors, calibration methods, and non-linear data processing in practical applications.