| Main Title |
Environmental effects on microphones of various constructions / |
| Author |
Hruska, Gale R.
|
| Other Authors |
|
| Publisher |
Dept. of Commerce, National Bureau of Standards : Reproduced by National Technical Information Service, |
| Year Published |
1976 |
| Report Number |
EPA/550-9-76-009; NBSIR-76-1090; NBS-2003110 |
| Stock Number |
PB-255 505 |
| OCLC Number |
04398474 |
| Subjects |
Microphone--Calibration
|
| Additional Subjects |
Microphones ;
Acoustic measurement ;
Calibrating ;
Electrets ;
Ceramics ;
Capacitors ;
Sensitivity ;
Humidity ;
Temperature ;
Environmental tests ;
Stability ;
|
| Internet Access |
|
| Holdings |
| Library |
Call Number |
Additional Info |
Location |
Last
Modified |
Checkout
Status |
| ELBD ARCHIVE |
EPA 550-9-76-009 |
Received from HQ |
AWBERC Library/Cincinnati,OH |
10/04/2023 |
| ESAD |
EPA 550-9-76-009 |
|
Region 10 Library/Seattle,WA |
12/19/2018 |
| NTIS |
PB-255 505 |
Some EPA libraries have a fiche copy filed under the call number shown. |
|
07/26/2022 |
|
| Collation |
24, A-8 pages : illustrations ; 28 cm |
| Abstract |
The pressure sensitivities of two 1/2-inch electret, two 1-inch ceramic, and two back-vented 1-inch condenser microphones were measured for numerous combinations of temperature, percentage relative humidity, and frequency. The two condenser microphones were calibrated by the reciprocity technique at each combination of temperature, relative humidity and frequency. The condenser microphones were then used as calibrated sources to determine the pressure sensitivities of the other microphones. Insert voltage techniques were used to eliminate the environmental effects on the electronics. It was found that the back-vented condenser microphones are insensitive to changes in relative humidity. At frequencies considerably below their resonance frequencies they exhibited only a very small change in sensitivity with temperature. At frequencies closer to the resonance frequency the temperature coefficient increases approximately fourfold. The temperature and humidity coefficient for the electret and ceramic microphones could not be determined due to the instability in their sensitivities which produced changes that were larger than those induced by the temperatures and humidities. |
| Notes |
"NBSIR 76-1090." "EPA/550-9-76-009." "PB-255 505." "July 1976." Includes bibliographical references. |
| Place Published |
Washington, D.C. |
| Corporate Au Added Ent |
Institute for Basic Standards (U.S.); United States. Office of Noise Abatement and Control. |
| NTIS Title Notes |
Final rept. Mar-Jun 75. |
| PUB Date Free Form |
1976 |
| Category Codes |
14B; 20A; 68B; 46A; 86V |
| NTIS Prices |
PC A03/MF A01 |
| BIB Level |
m |
| Medium |
unmediated |
| Content |
text |
| Carrier |
volume |
| Cataloging Source |
OCLC/T |
| Control Number |
326622819 |
| OCLC Time Stamp |
20181212064124 |
| Language |
eng |
| Origin |
OCLC |
| Type |
MERGE |
| OCLC Rec Leader |
01688cam 2200421Ia 45010 |
