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Minimum inhibitory concentration. In microbiology, the minimum inhibitory concentration ( MIC) is the lowest concentration of a chemical, usually a drug, which prevents visible in vitro growth of bacteria or fungi. [1] [2] MIC testing is performed in both diagnostic [1] [2] and drug discovery laboratories.
Microphone. Shure Brothers microphone, model 55S, multi-impedance "Small Unidyne" dynamic from 1951. A microphone, colloquially called a mic ( / maɪk / ), [1] or mike, [a] is a transducer that converts sound into an electrical signal.
The microphone's diaphragm is placed between the two ports; sound arriving from an ambient sound field reaches both ports more or less equally. Sound that's much closer to the front port than to the rear will make more of a pressure gradient between the front and back of the diaphragm, causing it to move more.
A boundary microphone (or pressure zone microphone) is one or more small omnidirectional or cardioid condenser mic capsule (s) positioned near or flush with a boundary (surface) such as a floor, table, or wall. The capsule (s) are typically mounted in a flat plate or housing. The arrangement provides a directional half-space pickup pattern ...
A sound level meter (also called sound pressure level meter ( SPL )) is used for acoustic measurements. It is commonly a hand-held instrument with a microphone. The best type of microphone for sound level meters is the condenser microphone, which combines precision with stability and reliability. [ 1] The diaphragm of the microphone responds to ...
An electret microphone is a microphone whose diaphragm forms a capacitor (historically-termed a condenser) that incorporates an electret. The electret's permanent electric dipole provides a constant charge Q on the capacitor. Sound waves move the diaphragm, changing the capacitance C, which produces a corresponding voltage change across the ...
An audio analyzer is a test and measurement instrument used to objectively quantify the audio performance of electronic and electro-acoustical devices. Audio quality metrics cover a wide variety of parameters, including level, gain, noise, harmonic and intermodulation distortion, frequency response, relative phase of signals, interchannel ...
A pistonphone is an acoustical calibrator (sound source) that uses a closed coupling volume to generate a precise sound pressure for the calibration of measurement microphones. The principle relies on a piston mechanically driven to move at a specified cyclic rate, pushing on a fixed volume of air to which the microphone under test is coupled.