Notes on Sensor Design.

Designing for sensor accuracy:

• ask yourself if you need absolute, relative or null measurement
• ask yourself if you need direct or indirect measurement
• ask yourself what precision and accuracy you need
• draw out and define the system
• with those answers in mind choose your sense methodology
• then choose your sensor+detector
• calculate the output equation that calculates the output from the input
• add all the sources of error to that equation

Some things to consider:

• size the detector output swing (output value from min to max) to the full range of the detector input
• understand your noise sources and choose a sensor that is less sensitive to these sources
• bound the error sources in your design, eg control the physical environment (like vibration), power supply voltages, etc to mitigate error (noise)
• use binning (to reduce process error)
• break out components and discreetly address error in each component and implement a more accurate version
• use multiple sensors (e.g. RSS or differential measurement)
• calibrate the remaining error
• pre-filter the source signal
• post-filter the output
• choose your bandwidth (or integration time) carefully
• make sure you utilize the full-scale voltage of each input stage
• perform a tolerance analysis of your design
• perform a sensitivity analysis of your design