Gracey & Associates Hire and Calibration
Measurement Microphones and Outdoor Microphones
Measurement microphone are widely used in noise measurements because they offer the best linearity, frequency range and high stability.
All the condenser microphones we supply conform to BS EN 61094 and may therefore be mechanically interchangeable. For example the B&K 4165, CEL 192-2F, GRAS 40AF and the Nor 1220 have similar mechanical and acoustical specifications.However some microphones are pre-polarized [electret] types and should not be confused with the air condenser types which require a polarization voltage **.
All our meters, microphones, accelerometers etc., are delivered with current calibration certificates, traceable to UKAS. Our ISO 9001 laboratory is audited by British Standards and we offer a microphone calibration service for all customers.
Measurement Microphones are very delicate and should be treated accordingly, the slightest 'touch' can rupture the diaphragm, which is why the protection grid should not, normally, be removed. They are also susceptible to damp so outdoor systems like the B&K UA 1404 or GRAS 41AL systems are recommended for all outside applications. Please take care as any damage must be charged for and usually means a replacement microphone. We also include a basic introduction to omnidirectional microphones.
Condenser Measurement Microphones Precision, Omni-directional
In this section we also include environmental and outdoor microphones, preamplifiers, multi-channel microphone power supplies, etc.,Note ¹ - these air condenser microphones are electrically, acoustically and mechanically compatible.
Note ² - these pre-polarized microphones are also interchangeable.
Note ³ - for use with outdoor microphones which are vertically aligned so sound source is at 90°.
Sound level measurements up to 165 dB may be made with the B&K 4135 and the GRAS 40BF microphone and a B&K 2250 analyzer.
* the B&K 4135 and GRAS 40BF prices include a 1/4" to 1/2" preamplifier adaptor and a 1/4" calibration coupler.
Standard microphones may also be used to measure extremely low sound pressure levels. To download the application note right click here and select 'Save ......'.
** Pre-polarized electret may be used in place of air condenser types if the 200 V polarization voltage can be switched off.
| B&K 3593 | Sound Intensity Probe | £ 27 a day * |
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The B&K 3595 is a two-microphone probe kit for measuring sound intensity. Designed for use with 2260E Hand-held Sound Intensity System, the probe set includes the 1/2" Sound Intensity Microphone Pair Type 4197 enabling 1/3-octave centre frequency measurements.
B&K 3595 Sound Intensity Probe - details
| GRAS 50AI | Sound Intensity Probe | £ 20 a day * |
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The GRAS sound intensity probe is durable and easy to use probe that fully complies with the requirements of IEC 1043 for Class 1 sound intensity probes.
The sound intensity probe includes a set of 1/2" intensity microphones type 40AI, with spacers,
adaptors, preamplifiers and a remote control handle to control the complete data acquisition
process from the probe handle, when used with the Nor 840 analyzer.
GRAS 50AI Sound Intensity Probe - details
| GRAS 40AK | Sound Intensity Microphone Set | £ 12 a day * |
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The GRAS sound intensity microphone sets includes two phase matched 1/2" intensity microphones, spacers and 1/4" preamplifier adaptors.
The microphones have a free field response optimized for use in face to face configuration intensity
probes and have high sensitivity to enable low level measurements.
GRAS 40AK Sound Intensity Microphones - details
| B&K UA 1404 | Outdoor Microphone Kit | £ 7 a day * |
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For use with the B&K 2236, 2238, 2250 and 2260 analyzers. The B&K Environmental microphone system which fits over the standard microphone and uses
an incidence corrector to compensate for the vertically mounted microphone and weather
See also the environmental kits linked to each meter description.
B&K Outdoor Microphone - details
| GRAS 41AL | Outdoor Microphone System | £ 8 a day * |
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The GRAS Outdoor Microphone is designed to maintain a microphone's specifications when fitted with a rain cover, windshield and mounted vertically .
The kit includes a 3 m preamplifier cable with a Lemo 1B connector, a desiccator unit and a coupler
with correction values for a range of calibrators.
GRAS Outdoor Microphone - details
| GRAS Microphone Preamplifiers | Daily Hire * | |
|---|---|---|
| GRAS 26AA | 1/4" with 0.3 m thin lead to Lemo 0B connector, used in GRAS 50AI sound intensity probe | £ 3 |
| GRAS 26AB | 1/4" with 1/2 " adaptor and integral Lemo 1B connector | £ 3 |
| GRAS 26AC | 1/4" with 2 m thin cable to Lemo 1B connector | £ 3 |
| GRAS 26AF | 1/2" with integral Lemo 1B connector - general purpose | £ 3 |
| GRAS 26AG | 1/2" with insert voltage connection, integral Lemo 1B | £ 3 |
| GRAS 26AK | 1/2" with integral Lemo 1B connector - general purpose | £ 3 |
Order preamplifier extension cables to suit your application. For more information on the GRAS preamplifiers click here
| Norsonic 1201 | Norsonic Microphone Preamplifier | £ 3 a day * |
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Norsonic 1/2" preamplifier with integral 1B connector - this is our general purpose preamplifier suitable for most applications. It has a very low self noise level. Its high input impedance ensures a good low frequency response and the output stage is designed to drive long cables with full frequency range.
There are a range of standard extension cable available including flat tape types to pass under doors etc.,
Nor 1201 Microphone Preamplifier Specifications
| GRAS 12AA | Microphone Power Supply - dual channel | £ 5 a day * |
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Dual channel, battery operated power supply for GRAS, Norsonic and other compatible preamplifiers with Lemo 1B 7-pin connectors. Ideal for use with GRAS 41AL outdoor microphone systems when the sound level meter to be used does not have Lemo preamplifier inputs and / or polarization voltage supplies.
GRAS 12AA Microphone Power Supply - details
| Norsonic 335 | Microphone Power Supply - 8 channels with signal conditioning | £ 19 a day * |
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Microphone and preamplifier power supplies with 200 V or 0 V polarisation voltage and signal conditioning for each channel - battery operated. Ideal for use with multi-channel analysers and data capture systems - shown here with an 8-channel DAT recorder.
Nor 335 Microphone Power Supply - details
| Norsonic 336 | Microphone Power Supply - dual channels with signal conditioning | £ 6 a day * |
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Battery operated, dual channel microphone power supply, preamplifier system. Often used as a 'remote' microphone system enabling long cables back to the analyser.
Other applications include using as a Front-end for DAT recorders and similar data capture/analysis systems.
Mechanically compatible with the Sony D7 and D8 DAT Recorders
Nor 336 Condenser Microphone Power Supply - details
* Our standard hire charges are based on a 4-day minimum period, details other options.
Gracey & Associates 01933 624212 hire@gracey.com
British Standards accreditation for noise and vibration instrument hire and calibration.
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Measurement Microphone Keywords: condenser, B&K, GRAS, Bruel Kjaer, omnidirectional, outdoor microphone, microphone calibration
Glossary: free field l omnidirectional, omni directional