Electronics

          Human senses and human body Photometry is the measurement of light in terms of its perceived brightness to the human eye. Photometric quantities derive from analogous radiometric quantities by weighting the contribution of each wavelength by a luminosity function that models the eye's spectral sensitivity. For the ranges of possible values, see the orders of magnitude in: illuminance, luminance, and luminous flux. ·     Lux meter for measuring illuminance, i.e. incident luminous flux per unit area ·   Luminance meter for measuring luminance, i.e. luminous flux per unit area and unit solid angle ·    Light meter, an instrument used to set photographic exposures. It can be either a lux meter (incident-light meter) or a luminance meter (reflected-light meter), and is calibrated in photographic units. ·    Integrating sphere for collecting the total luminous flux of a light source, which can then be measured b...

More on continuum mechanics This includes mostly instruments which measure macroscopic properties of matter: In the fields of solid state physics; in condensed matter physics which considers solids, liquids and in-betweens exhibiting for example viscoelastic behavior. Furthermore, fluid mechanics, where liquids, gases, plasmas and in-betweens like supercritical fluids are studied. Density This refers to particle density of fluids and compact(ed) solids like crystals, in contrast to bulk density of grainy or porous solids. Aerometer liquids Dasymeter gases Gas collecting tube gases Hydrometer liquids Pycnometer liquids Resonant frequency and Damping Analyser (RFDA) solids For the ranges of density-values see: Orders of magnitude (density) Hardness of a solid Durometer Shape and surface of a solid ...

Thermodynamics Temperature-related considerations dominate thermodynamics. There are two distinct thermal properties: A thermal potential — the temperature. For example: A glowing coal has a different thermal quality than a non-glowing one. And a substance-like property, — the entropy; for example: One glowing coal won't heat a pot of water, but a hundred will. Energy in thermodynamics is calculated by multipying the thermal potential by the amount of entropy found at that potential: temperature times entropy. Entropy can be created by friction but not annihilated. Thermodynamics (or mole number) A physical quantity introduced in chemistry; usually determined indirectly. If mass and substance type of the sample are known, then atomic- or molecular masses (taken from a periodic table, masses measured by mass spectrometry) give direct access to the value of the amount of substance. See also the article about mo...

Electricity, electronics and electrical engineering Considerations related to electric charge dominate electricity and electronics. Electrical charges interact via a field. That field is called electric if the charge doesn't move. If the charge moves, thus realizing an electric current, especially in an electrically neutral conductor, that field is called magnetic. Electricity can be given a quality — a potential. And electricity has a substance-like property, the electric charge. Energy (or power) in elementary electrodynamics is calculated by multiplying the potential by the amount of charge (or current) found at that potential: potential times charge (or current). (See Classical electromagnetism and its Covariant formulation of classical electromagnetism) Electric charge Torsion balance used by Coulomb to establish a relation between charges and force, see above. For the range...

power(flux of energy) A physical system that exchanges energy may be described by the amount of energy exchanged per time-interval, also called power or flux of energy. (see any measurement device for power below) For the ranges of power-values see: Orders of magnitude (power). Action Action describes energy summed up over the time a process lasts (time integral over energy). Its dimension is the same as that of an angular momentum. A phototube provides a voltage measurement which permits the calculation of the quantized action (Planck constant) of light. Also see photoelectric effect. Mechanics This includes basic quantities found in classical- and continuum mechanics; but strives to exclude temperature-related questions or quantities . Length (distance) Length, distance, or range meter For the ranges of length-values see: Orders of magnitude (leng...

Test& Measurement World Test & Measurement World (ISSN 0744-1657) was a magazine published from January 1981 to July 2012 and website that was stopped in June 2013 by UBM Electronics, a division of United Business Media. Former owner Reed Business Information sold the magazine to Canon Communications in February 2010; in October 2010 Canon Communications was acquired by United Business Media. Test & Measurement World served the information needs of engineers in the electronic original equipment market (EOEM), which includes manufacturers of test equipment, medical equipment, aircraft, and aerospace, automotive, consumer electronics, and other products and services, as well as engineers in the electronic test, measurement, and inspection industries. Engineers can access technical information geared for on-the-job application, as well as industry news, coverage of the latest standards and technologies, application notes, p...

LAN Extensions for Instrumentation The LXI (LXI) Standard defines the communication protocols for instrumentation and data acquisition systems using Ethernet. These systems are based on small, modular instruments, using low-cost, open-standard LAN (Ethernet). LXI-compliant instruments offer the size and integration advantages of modular instruments without the cost and form factor constraints of card-cage architectures. Through the use of Ethernet communications, the LXI Standard allows for flexible packaging, high-speed I/O, and standardized use of LAN connectivity in a broad range of commercial, industrial, aerospace, and military applications. Every LXI-compliant instrument includes an Interchangeable Virtual Instrument (IVI) driver to simplify communication with non-LXI instruments, so LXI-compliant devices can communicate with devices that are not themselves LXI compliant (i.e., instruments that employ GPIB, VXI, PXI, etc.). This simplifies building and operating hyb...

Platforms GPIB/IEEE-488 Several modular electronic instrumentation platforms are currently in common use for configuring automated electronic test and measurement systems. These systems are widely employed for incoming inspection, quality assurance, and production testing of electronic devices and subassemblies. Industry-standard communication interfaces link signal sources with measurement instruments in “rack-and-stack” or chassis-/mainframe-based systems, often under the control of a custom software application running on an external PC. The General Purpose Interface Bus (GPIB) is an IEEE-488 (a standard created by the Institute of Electrical and Electronics Engineers) standard parallel interface used for attaching sensors and programmable instruments to a computer. GPIB is a digital 8-bit parallel communications interface capable of achieving data transfers of more than 8 Mbytes/s. It allows daisy-chaining up to 14 instruments to a system controller using a 24-pin con...

Types of test equipment Basic equipment Voltmeter (Measures voltage)The following items are used for basic measurement of voltages, currents, and components in the circuit under test. Ohmmeter (Measures resistance) Ammeter, e.g. Galvanometer or Milliameter (Measures current) Multimeter e.g., VOM (Volt-Ohm-Milliameter) or DMM (Digital Multimeter) (Measures all of the above) RLC Meter e.g., RLC meter or Resistance,Inductance and capacitance meter (measure RLC values) Power supplies Signal generator Digital pattern generator Pulse generator Frequency counter (Measures frequency) Test probes The following are used for stimulus of the circuit under test: Oscilloscope (Displays voltage as it changes over time)The following analyze the response of the circuit under test: And connecting it all together: Advanced or less commonly used equipment Meters Solenoid vo...