Sound intensity calibrator Nor1254

Sound intensity calibrator Nor1254

Sound intensity calibrator Nor1254

Description

<h2 title=”Sound intensity calibrator Nor1254″>Sound intensity calibrator Nor1254</h2>
<a href=”http://norsonic.asia/wp-content/uploads/2015/04/Sound-intensity-calibrator-Nor1254.jpg”><img class=”size-full wp-image-414″ src=”http://norsonic.asia/wp-content/uploads/2015/04/Sound-intensity-calibrator-Nor1254.jpg” alt=”Sound intensity calibrator Nor1254″ width=”400″ height=”300″ /></a> Sound intensity calibrator Nor1254

The sound intensity calibrator Nor1254 is a applicable for residual intensity testing, sound intensity level calibration and particle velocity calibration as specified in EN IEC 61043 Electroacoustics – Instruments for the measurements of sound intensity – Measurements with pairs of pressure sensing microphones.

The sound intensity is connected to an external electrical signal source, such as the signal generator output on the Real Time Analyser Nor840. Recommended signal is pink or red/white noise.

The most important characteristics of a sound intensity probe will be the ability to measure the real part of the complex sound intensity in highly reactive sound fields and in sound fields with high background noise. This ability is mainly determined by the phase characteristics of the intensity microphones. For high quality intensity-microphone pairs, the phase difference is extremely small.

The Nor1254 consists of a sound source supplying a well defined sound pressure field simultaneously to the diaphragms of two measurement microphones. When used for residual intensity testing the sound pressures at the diaphragms of the two microphones are exactly the same, with an extremely small phase difference. The phase difference expresses the Pressure-Intensity (PI) Index for a certain nominal microphone separation. EN IEC 61043 states the PI Index for a nominal microphone separation of 25mm. The PI index for the Sound Intensity Calibrator normalised to a microphone spacing of 25mm should be more than 27dB, corresponding to a phase difference of less than 0.006° at 100Hz.

For sound intensity and particle velocity calibration a phase shifting element is inserted between the source and receiving part of the calibrator. This results in a phase shift of the sound pressure at one of the microphones similar to that found in a free field. This result is an output from the microphones similar to what would be obtained if the microphones were placed in a free field.

The calibrator can be used with ½” or ¼” microphones, the latter by use of adaptors.
<table>
<tbody>
<tr class=”first odd”>
<td class=”first odd”>Input connector</td>
<td class=”last even”>BNC</td>
</tr>
<tr class=”even”>
<td class=”first odd”>Maximum input signal</td>
<td class=”last even”>1Vrms (recommended signal is 300mVrms)</td>
</tr>
<tr class=”odd”>
<td class=”first odd”>SPL level re. 20µPa
at 300mVrms input signal</td>
<td class=”last even”>115 dB (approximately)</td>
</tr>
<tr class=”even”>
<td class=”first odd”>Frequency range</td>
<td class=”last even”>40Hz – 8kHz</td>
</tr>
<tr class=”odd”>
<td class=”first odd”>Pressure-Intensity Index</td>
<td class=”last even”>&gt;27dB (for 25mm nominal microphone spacing)</td>
</tr>
<tr class=”even”>
<td class=”first odd”>SPL difference between channels</td>
<td class=”last even”>&lt; 0.1dB</td>
</tr>
<tr class=”odd”>
<td class=”first odd”>Operating Temperature Range</td>
<td class=”last even”>+5 to + 40°C</td>
</tr>
<tr class=”even”>
<td class=”first odd”>Dimensions (H×W×D)</td>
<td class=”last even”>42,2×50,3×60,0 mm</td>
</tr>
<tr class=”odd”>
<td class=”first odd”>Weight:</td>
<td class=”last even”>515g. (1.3lbs)</td>
</tr>
<tr class=”even”>
<td class=”first odd”>CE classification</td>
<td class=”last even”>EMC: EN50081-1, EN 50082-1
Safety: EN 61010-1, 1993 portable equipment pollution category 2</td>
</tr>
<tr class=”last odd”>
<td class=”first odd”>Accessories included</td>
<td class=”last even”>Phase shifting element; two ¼” adaptors; BNC cable;
calibration certificate; instruction manual; carrying case</td>
</tr>
</tbody>
</table>