PoMS
68 flashcards · Physics · by Kristóf Nagy
Degrees of Freedom
The number of independent pieces of information used in calculating a statistical estimate31....
Measurement System
A system that transforms an input quantity into an output quantity that can be observed or recorded2.
Sensor
The element that responds directly to the physical quantity being measured3.
Transducer
Converts the sensed quantity into a usable electrical or mechanical signal3.
Experimental Test Plan
A structured approach to making measurements to answer a specific question, including identifying variables and controlling influences4....
Random Error
Errors that cause data scatter, varying randomly with each measurement6.
Systematic Error
Errors that remain constant in repeated measurements, causing a constant offset in the indicated value6....
Uncertainty
A numerical estimate of the possible range of error in the stated value of a variable6.
Standards
Agreed-upon references for comparing equipment performance or ensuring consistent and safe operation8.
Significant Digits
The number of digits that reflect the level of confidence and relevance in a reported value9.
Variable
A physical quantity whose value influences the test result10....
Continuous Variable
A variable that can take any value within a given range10.
Discrete Variable
A variable that can only take specific, separate values10.
Dependent Variable
A variable affected by changes in the value of one or more other variables10....
Independent Variable
A variable that is not influenced by changes in other variables10....
Extraneous Variable
A variable not purposely manipulated but affects the test result11.
Noise
Random variations in the volume of a measured signal12.
Interference
Undesirable trends imposed on a measured signal12.
Randomisation
A method used to control the source of interference or break up its trend12....
Range
The limits within which an instrument is designed to operate14.
Span
The difference between the maximum and minimum values of an instrument's range14....
Accuracy
A qualitative term referring to the closeness of a measurement to the true value14....
Hysteresis Error
The difference in the instrument's output for the same input when approached from different directions, usually in a cycle.14....
Linearity Error
The deviation of the instrument's output from a linear relationship with the input14....
Sensitivity Error
Error related to the change in the output for a change in the measured quantity, such as the effect of temperature14....
Repeatability
The ability of an instrument to give the same output for the same input when measurements are repeated14.
Reproducibility
The ability of an instrument to give the same output for the same input when measurements are made under different conditions14.
Verification
The process of ensuring a system meets its specified requirements14.
Validation
The process of ensuring a system meets the needs of the user and the intended purpose14....
Primary Unit Standards
The highest level of standards used to define units19.
Thermocouple
A temperature sensor that operates on the principle of the Seebeck effect, generating a voltage based on temperature differences at junctions of dissimilar metals19....
Input Signal
The physical quantity applied to the measurement system19.
Output Signal
The resulting signal produced by a measurement system19.
Analog Signal
A signal that is continuous in time and magnitude21....
Discrete Time Signal
A signal for which information is available only at discrete points in time21....
Digital Signal
A signal with discrete values in both time and magnitude, resulting from quantization21....
ADC (Analog-to-Digital Converter)
A device that converts a continuous analog signal to a discrete digital signal23.
DAC (Digital-to-Analog Converter)
A device that converts a digital signal into an analog signal23.
Harmonics
Integer multiples of the fundamental frequency of a signal23.
Fourier Series
A mathematical representation of a periodic signal as a sum of sine and cosine waves23.
PMT (Photomultiplier Tube)
A highly sensitive vacuum tube that converts light into an electrical signal, often used in detecting low light levels24.
SiPM (Silicon Photomultiplier)
A solid-state device composed of an array of single-photon avalanche diodes (SPADs) to detect light24.
Zero-Order System
A measurement system where the output is directly proportional to the input without any time delay or dynamic effects25....
First-Order System
A system where the output response to a step input is characterised by an exponential rise or decay, described by a time constant25....
Error Fraction
The ratio of the error to the full scale of the measuring system25.
Rise Time
The time it takes for the output of a system to reach a specified percentage (typically 90%) of its final value in response to a step input27.
Time Constant
A parameter that describes the rate of the output's response to a step input for first-order systems27.
Second-Order System
A system characterized by a damped oscillatory response to a step input, with properties like natural frequency and damping ratio26....
Resonance Band
The frequency range where the amplitude of a second-order system's output is significantly amplified, potentially leading to instability27.
Random Variable
A variable whose value is a numerical outcome of a random phenomenon28.
Probability Density Function (PDF)
A function that describes the likelihood of a continuous random variable taking on a given value28....
Histogram
A graphical representation of the distribution of numerical data28....
Standard Statistical Distributions
Known mathematical models used to describe the behaviour of populations or samples of data28.
Normal Distribution
A common continuous probability distribution that has a bell-shaped curve and is symmetrical around the mean31....
Chi-Squared Distribution
A distribution often used in hypothesis testing and goodness of fit tests31....
Least-Squares Regression Analysis
A statistical method used to find the best fit for a set of data points with a curve or line31.
Data Outlier
A data point that significantly differs from other data points and may be due to a data entry or measurement error31.
Monte Carlo Simulation
A computational algorithm that uses repeated random sampling to model a system31....
Wheatstone Bridge
An electrical circuit used to measure an unknown resistance by balancing two legs of a bridge circuit36.
Ohm's Law
A basic electrical law, stating that voltage (U) equals current (I) multiplied by resistance (R), i.e. U = I * R37.
Power Equation
The equation that defines power (P) as the product of voltage (U) and current (I), i.e. P = I * U37.
DC (Direct Current)
An electrical current that flows consistently in one direction36.
AC (Alternating Current)
An electrical current that periodically reverses direction36.
Bio-inspired Systems
Systems or technologies designed based on observations from biological systems and structures38.
Photophysics
The study of the physical properties and processes of light-matter interaction38.
Optoelectronics
The technology combining optics and electronics38.
Multiplexing
Combining multiple signals for transmission over a single channel or path39.
Data Compression
Reducing the size of data to save space in storage or bandwidth during transmission39.