Explain the concept of uncertainty in measurement.

Uncertainty in measurement refers to the doubt that exists about the result of any measurement. It's not simply an error, but rather a range of values within which the true value of the measured quantity is believed to lie. Every measurement, no matter how carefully performed, is subject to some degree of uncertainty due to limitations of the measuring instrument, the measurement procedure, and the observer. Uncertainty is quantified by assigning a numerical value to the range of possible values around the measured result. For example, when measuring the voltage of a power supply with a multimeter, the reading might be 12.0 volts, but the multimeter's specifications may indicate an uncertainty of ±0.1 volts. This means that the true voltage is likely to be somewhere between 11.9 volts and 12.1 volts. Sources of uncertainty can be categorized as either random or systematic. Random uncertainties are due to unpredictable variations in the measurement process, such as slight fluctuations in ambient temperature or variations in the observer's judgment. Systematic uncertainties are due to consistent biases in the measurement process, such as a calibration error in the measuring instrument or an incorrect measurement technique. Evaluating and reporting uncertainty is crucial for ensuring the reliability and comparability of measurement results. It allows users of the data to assess the quality of the measurement and to make informed decisions based on the results. In medical device calibration, understanding and quantifying uncertainty is essential for ensuring that the device is performing within its specified tolerances and that the measurements are accurate enough for their intended use.