=blue>the Internet Archive. Yahoo! is not affiliated with the authors of this page or responsible for its content.
LarsonDavis Model CAL291 Residual Intensity Calibrator
LARSONDAVIS

LarsonDavis Laboratories - Model 2226 Brochure
May 1, 1997

LarsonDavis Model CAL291
Residual Intensity Calibrator

Photo of CAL291 with 2260 Intensity Probe

Under IEC and ANSI standards, a sound intensity measuring sys-
tem consists of a two microphone sound intensity probe and a
dual channel processor. The accuracy of the intensity measure-
ment is strongly dependent upon the phase accuracy between
the two measurement channels, including the microphones.
Sound intensity measurement systems are classified into Class 1
or 2 based upon the pressure-residual-intensity index which is
measured using a residual intensity testing device.
The LarsonDavis Model CAL291 Residual Intensity Calibrator
satisfies the residual intensity test device specifications of both
IEC 1043:1993 and ANSI S1.9-1996.

Features
Applies the same signal with zero phase difference to a pair
of 1/2" or 1/4" microphones Driven by external signal generators such as the following
versions available with the LarsonDavis Models 2800/
2900 and 3200 Real-time Analyzers:
OPT 10 Noise Generator; pink or white broadband noise
OPT 11 Digital Signal Generator; Sinusoidal, pink or
white broadband noise, 1/3 octave bandlimited pink
pseudo random noise and white pseudo random noise Amplifier provides signal levels to 127 dB

Applications

Testing of sound intensity measurement systems Generation of signals for verification of the
amplitude/phase accuracy of multi-channel acoustic
measurement systems Amplitude/Phase Normalization. The digital filters of the
Larson Davis analyzers provide both amplitude and phase,
permitting the measurement of the complex transfer func-
tion between two measurement channels, including
microphones, in 1/3 octave bands by using the CAL291 to
excite both microphones with broadband noise. From this
a correction function can be generated within the analyzer
to correct for any amplitude and phase errors which may
have existed between channels previous to the normaliza-
tion procedure.
2
LarsonDavis Laboratories - Model 2226 Brochure
May 1, 1997

Specications

Standards

Meets the residual intensity test device specifications as pre-
sented in IEC 1043:1993 Instruments for the measurement of
sound intensity and ANSI S1.9-1996 Instruments for the mea-
surement of sound intensity.

Input

Connector:
BNC
Impedance:
1 M

Output
Sound Pressure Level), 1% harmonic distortion):
25 - 127 dB @ 1 kHz SPL difference between channels: < 0.1 dB @ 1 kHz Maximum pressure-intensity index: > 27 dB Intensity Output when used with adaptor (nominal):
L

I

= L

P

@ 1 kHz Output Level and Maximum Input Voltage);
<1% distortion)

Power

DC Power:
9 - 16 Vdc, 400 mA provided by
PSA004 DC Power Supply (included)
90-264 Vac @ 50 - 60 Hz
CE-mark indicates compliance with EMC
Directive and Low Voltage Directive.

Frequency,
Hz
Output SPL, dB
re. 20 (Pa
Max. Input Voltage,
dB

µ

V

250
127
124.0
1 k
124
126.9
2.5 k
112
125.5
6.3 k
107
113.5

Mechanical Characteristics

Length

25.6 cm (10.3 in)

Width

10.0 cm (4.0 in)

Height

5.3 cm (2.1 in)

Weight

1.0 kg (2.2 lb.)


LarsonDavis
A Family of Quality
Larson Davis
1681 West 820 North
Provo, UT 84601
U.S.A.
PH: 801 375-0177 FAX: 801 375-0182
E-mail: marketing@larsondavis.com
For Sound/Vibration Measurement
Look to LarsonDavis
http://www.larsondavis.com