Lecture

Measurement Principles: Calibration and Sensitivity Examples

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Description

This lecture covers fundamental measurement principles through various examples. It begins with a calibration test using a digital voltmeter to measure a known battery voltage, where the instructor explains how to estimate systematic and random errors from the readings. The second example involves a pressure sensing device, where the instructor calculates the sensitivity based on given input and output values. The lecture then discusses the specifications of a voltmeter, determining the appropriate range for measuring a 4.8 V battery while considering resolution and uncertainty. Finally, the instructor introduces planar laser induced fluorescence (PLIF) as an optical measurement technique, explaining how light intensity is converted to concentration values. The lecture concludes with a discussion on the input and output ranges, resolution, and dynamic range of different bit depth cameras used in PLIF, emphasizing the importance of selecting the right equipment for accurate measurements.

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Related concepts (32)

Dynamic range compression

Dynamic range compression (DRC) or simply compression is an audio signal processing operation that reduces the volume of loud sounds or amplifies quiet sounds, thus reducing or compressing an audio signal's dynamic range. Compression is commonly used in sound recording and reproduction, broadcasting, live sound reinforcement and in some instrument amplifiers. A dedicated electronic hardware unit or audio software that applies compression is called a compressor.

Voltmeter

A voltmeter is an instrument used for measuring electric potential difference between two points in an electric circuit. It is connected in parallel. It usually has a high resistance so that it takes negligible current from the circuit. Analog voltmeters move a pointer across a scale in proportion to the voltage measured and can be built from a galvanometer and series resistor. Meters using amplifiers can measure tiny voltages of microvolts or less. Digital voltmeters give a numerical display of voltage by use of an analog-to-digital converter.

Voltage

Voltage, also known as electric pressure, electric tension, or (electric) potential difference, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to move a test charge between the two points. In the International System of Units (SI), the derived unit for voltage is named volt. The voltage between points can be caused by the build-up of electric charge (e.g., a capacitor), and from an electromotive force (e.g.

Measurement uncertainty

In metrology, measurement uncertainty is the expression of the statistical dispersion of the values attributed to a measured quantity. All measurements are subject to uncertainty and a measurement result is complete only when it is accompanied by a statement of the associated uncertainty, such as the standard deviation. By international agreement, this uncertainty has a probabilistic basis and reflects incomplete knowledge of the quantity value. It is a non-negative parameter.

Observational error

Observational error (or measurement error) is the difference between a measured value of a quantity and its true value. In statistics, an error is not necessarily a "mistake". Variability is an inherent part of the results of measurements and of the measurement process. Measurement errors can be divided into two components: random and systematic. Random errors are errors in measurement that lead to measurable values being inconsistent when repeated measurements of a constant attribute or quantity are taken.

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