Instrument Calibration and Scale Design
Calibration is the documented comparison of an instrument's indications with traceable reference values to establish a correction relation, sensitivity, usable range, resolution, and associated uncertainty.
Why this shows up in the exam
Thermometer calibration · Sensor transfer curves · Balance and meter verification
Learn the idea
Calibration maps instrument indication to known reference inputs and exposes offset, sensitivity, and nonlinearity. A scale is trustworthy only after known inputs show what each indication means across the intended range.
🧠 Memory hook: Known inputs teach the scale what its marks mean.
Get this one clearly and it pays off every single time it shows up in the paper. 🎯
Formulas & facts to keep ready
- indication = sensitivity x input + offset — linear calibration model
- corrected input = (indication-offset)/sensitivity — inverse linear correction
How to approach it
- 1Choose reference points across the range
- 2Fit the stated calibration relation
- 3Apply correction with its valid range and uncertainty
Common slip-ups that cost marks
- •Using a one-point check to establish sensitivity
- •Extrapolating beyond calibrated range
- •Confusing calibration correction with random scatter
🌟 That's the whole idea — you've got this. Try the practice set below; every question you attempt makes it stick a little harder.
Original chapter practice
Original questions for this chapter, not past-paper questions or an exact mapping to this individual concept.
A quantity Q is defined as Q = force^1 / speed^2. Which dimensional formula represents Q?
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