Help with Measurement Microphones specifications:
Microphone Specifications
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| Sound Field Type | |||
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| Pressure Field | A pressure field is characterized by sound pressure with the same magnitude and phase throughout the field. This is the condition when the microphone sensor is small in relation to the wavelength of the sound. | ||
| Free-Field | Plane wave propagating freely in one defined direction. This is a somewhat theoretical condition representing a point source of sound producing an essentially plane wave at a distance with no reflection off surfaces. A practical free field can be realized at 2 meters or more from a sound source with no other interfering sources. | ||
| Diffuse Field | Sound waves arriving approximately simultaneously from all directions ("Random Incidence"). Sensitivity is frequently calculated using free-field measurements. True diffuse fields are closely approximated by hard-walled chambers with many noise sources such as factories. | ||
| Search Logic: | All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches. | ||
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| Frequency Response | Frequency response is the range of frequencies for which the microphone maintains a constant sensitivity within defined boundaries. Variation from this "linear" or "flat" sensitivity is given in dB; bounds that the define the linear frequency response will be in the form of ±3dB, -1dB/+4dB, etc. | ||
| Search Logic: | User may specify either, both, or neither of the limits in a "From - To" range; when both are specified, matching products will cover entire range. Products returned as matches will meet all specified criteria. | ||
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| Dynamic Range | Dynamic range is the range of sound pressure levels (dB) for which the microphone will meet its performance specifications; it is limited on the low end by the inherent noise of the acoustic system and on the high end by the maximum sound pressure level. The standard unit for measuring sound pressure level (SPL) is the deciBel (dB) with a reference pressure of 20 micro Pascals (20 μPa), which is the human hearing threshold. | ||
| Search Logic: | User may specify either, both, or neither of the limits in a "From - To" range; when both are specified, matching products will cover entire range. Products returned as matches will meet all specified criteria. | ||
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| Microphone Sensitivity: | Measure of how responsive or "hot" a microphone is. Sensitivity may be given in millivolt output per Pascal of sound pressure, or may be specified in dBV (dB), in which case it is typically a negative number. A correctly specified signal should exceed the inherent noise of the system yet not overload the preamplifier. | ||
| Search Logic: | User may specify either, both, or neither of the "At Least" and "No More Than" values. Products returned as matches will meet all specified criteria. | ||
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| Signal to Noise Ratio | Logarithmic ratio of the signal level produced by a standard pressure signal (e.g., 94 dB SPL) to the noise floor. S/N Ratio is typically expressed in dBV, or often dB for short. | ||
| Search Logic: | User may specify either, both, or neither of the "At Least" and "No More Than" values. Products returned as matches will meet all specified criteria. | ||
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| Impedance | Impedance is the resistance to flow of alternating current. Low impedance microphones exhibit values such as 100-500 ohms, whereas high impedance microphones can be 10,000 ohms or more. | ||
| Search Logic: | User may specify either, both, or neither of the "At Least" and "No More Than" values. Products returned as matches will meet all specified criteria. | ||
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Microphone Dimensions
Values are typically nominal.
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| Nominal Diameter | Different diameter microphones have differing dynamic characteristics. In general, larger diaphragms are more sensitive and have narrower frequency response; individual microphone specifications may vary. Microphone diameter is usually a nominal measurement. The most common choices are listed but may not be exact. A 1/2" microphone may actually be 13.2mm, for example, and a 25.2mm diameter microphone would be listed as 1". | ||
| Your choices are... | |||
| 1/8" | |||
| 1/4" | |||
| 1/2" | |||
| 1" | |||
| Other | Other unlisted microphone size. | ||
| Search Logic: | All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches. | ||
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| Actual Diameter / Size | True diameter or width measurement. | ||
| Search Logic: | User may specify either, both, or neither of the "At Least" and "No More Than" values. Products returned as matches will meet all specified criteria. | ||
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| Thickness / Height | Thickness or height of microphone; for assemblies or long probe microphones, this value represents the length. | ||
| Search Logic: | User may specify either, both, or neither of the "At Least" and "No More Than" values. Products returned as matches will meet all specified criteria. | ||
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Features & Applications
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| Features | |||
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| Digital Microphone | Microphone with integral analog-to-digital converter to render sound into computer-recognized format. Possible applications include voice recognition, recording onto a digital voice recorder, etc. | ||
| Wireless Microphone | Microphone contains radio transmitter or other wireless capability. | ||
| Integral Pre-amplifier | Boosts the microphone output from a small to intermediate level. | ||
| Probe Style | Long tip for measuring near-field levels or hard to reach areas. | ||
| Array Type | Style to measure 3-D sound field around a test object. | ||
| Outdoor Rated | Designed for use outdoors and in weather. | ||
| Wind Screen | Diffuser, often foam, which minimizes wind noise. | ||
| Turbulence Screen | Screen which minimizes noise from turbulence in pipes, ducts, etc. | ||
| Sound Intensity Probe | Sound intensity is measured by an instrument with closely matched microphone pairs. | ||
| Search Logic: | All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches. | ||
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| Polarization | Measurement condenser microphones may have a prepolarized electret back-plate or utilize external capacitor polarization. External polarization requires a separate power supply. | ||
| Your choices are... | |||
| Externally Polarized | Requires an external power source for excitation voltage or diaphragm capacitor charging. | ||
| Prepolarized Electret | Condenser microphone with back-plate coated with charged material; capacitor requires no external charging. | ||
| Search Logic: | All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches. | ||
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| Operating / Polarization Voltage | Voltage at which the microphone will operate. Voltage may be externally supplied or generated by a polarized electret. | ||
| Search Logic: | User may specify either, both, or neither of the "At Least" and "No More Than" values. Products returned as matches will meet all specified criteria. | ||
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Environment
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| Operating Humidity Range: | Rated humidity range for microphone operation. | ||
| Search Logic: | User may specify either, both, or neither of the limits in a "From - To" range; when both are specified, matching products will cover entire range. Products returned as matches will meet all specified criteria. | ||
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| Operating Temperature Range: | Rated temperature range for microphone operation. | ||
| Search Logic: | User may specify either, both, or neither of the limits in a "From - To" range; when both are specified, matching products will cover entire range. Products returned as matches will meet all specified criteria. | ||
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