5 January 2005 – This contact update page has been added to the Acrobat document you have downloaded. Please disregard any contact information printed within the document. Our Mailing and Shipping Address: White Instruments Div. C Van R, Inc. 1514 Ed Bluestein Blvd., Suite 201 (for U.S. Mail) Austin, TX 78721 U.S.A. Phone: 512-389-5358 Fax: 512-301-3932 Main Email Address: cvanr@whiteinstruments.com World Wide Web Site: http://www.whiteinstruments.
Model 140 Sound Analyzer Model 140 Sound Analyzer................................................................................................. 3 Specifications ...................................................................................................................... 4 Model 140 Sound Analyzer - Users' Manual ...................................................................... 6 A. UNPACKING AND INSTALLATION.................................................................. 6 B.
b. PRE-AMP OUT ............................................................................................ 14 c. COMMON .................................................................................................... 15 d. REMOTE ...................................................................................................... 15 e. SYNC ............................................................................................................ 15 f. NOISE OUT..............................
Model 140 Sound Analyzer DISPLAY APPLICATIONS Brilliant LED display gives a graphic point by point readout. Clearly readable from a distance. The Model 140 has many applications as a REAL TIME SPECTRUM ANALYZER in the audio frequency range. FILTERS SOUND REINFORCEMENT SYSTEMS EQUALIZATION 27 double tuned 1/3 octave filters on I.S.O. standard centers from 40 Hz to 16 kHz. Filters double tuned for greater selectivity and rejection of out-of-band noise.
Specifications DISPLAY NOISE GENERATOR 11 x 28 array of red light emitting diodes Output level may be selected for 20 mVrms or 0.
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Model 140 Sound Analyzer - Users' Manual A. UNPACKING AND INSTALLATION The Model 140 will be shipped fully insured for damage or loss unless the purchaser gives instructions for a different mode of insurance. The package should be examined for external damage, and then for internal impairment. Any claim for transit damage should be filed promptly with the carrier. White Instruments will cooperate in obtaining early repairs or replacement.
B. INTRODUCTION 1. Description The Model 140 Sound Analyzer is a real time analyzer for signals in the acoustic range of 35Hz to 18kHz. It contains a high-gain preamplifier matched to a dynamic microphone of 150 to 200ohms source-impedance, as well as a higher level input characteristic of a 600ohm line. It contains twenty-seven 1/3 octave filters on ISO centers from 40Hz to 16kHz, operating in parallel for continuous display on all channels, plus a broad-band channel calibrated in dB-SPL.
noise, an equalizer filter set may then be adjusted to give the desired room response curve. The results of the filter adjustments are continuously displayed on the Model 140 so that filter adjustments are quickly made. In the installation of a masking noise system for an open plan office, a shaped noise spectrum is desirable and will usually be specified.
C. CONTROL FUNCTIONS 1. Power The power switch is a push-on, push-off type switch. It has a neon lamp indicator built into its plastic button and should never need maintenance. 2. Noise Level The output level of the internal pink noise generator may be selected via the push-pull switch on the level potentiometer. The level knob is pushed in for low level (microphone level) and is pulled out for high level (line level) noise signal.
7. Display (-dB) This control allow centering of the 1/3 octave display columns to compensate for the approximate 16dB difference in signal level between vide-band pink noise out of the generator and the signal level in each 1/3 octave band. True level readings in each 1/3 octave band may be obtained by adding the indicated level on the display to the dB-SPL switch setting and SUBTRACTING the setting of the Display (-dB) switch (assuming a calibrated microphone is being used).
D. OPERATING INSTRUCTIONS AND APPLICATIONS 1. General The principles of operation of the internal component blocks are described later in the manual. Here, it will be assumed that the operator is familiar with the general problems of spectrum analysis and the explanations will be confined to the controls of this instrument. The Model 140 is turned on by a front panel push switch with a pilot light. There is a little warm-up time required.
There is a gain adjustment potentiometer with a range of about plus-minus 3dB located on top of the shielded input transformer, reached by removing the instrument from its case or dust shroud. With this adjustment, the analyzer may be recalibrated with a test signal, or adjusted to read directly with a microphone having a sensitivity different from the standard value. The maximum signal that be inserted at the "Microphone" input is 8.2 mVrms sine wave.
6. Equalization of a Sound Reinforcement System It will be assumed that the necessary equalizer filters are in place in the amplifier chain, and that the sound system is operational and ready for final adjustment. The procedure for using the Model 140 as an aid to the equalization process may use either a single microphone as the room sound level pickup, or up to three microphones with the "MIC PLEXOR" accessory.
A plastic sheet with a display grid printed on it is furnished with the instrument. This fits in front of the LED display. By using a soft wax pencil (such as a china marking pencil) date may be quickly copied off, and then transferred to a permanent record at leisure. Further, desired response curve shapes may be drawn on the plastic sheet for use as an overlay during adjustment of a filter set to a desired response.
c. COMMON This is circuit COMMON from which all other inputs and outputs are referenced. d. REMOTE The scanned output from each filter channel is available at this terminal. Connection may be made to the vertical axis of an oscilloscope for the remote display of the filtered signal plus the wide band SPL channel. The REMOTE output is positive and varies from +2.3 volts to +6.6 volts for the 20dB range, or from +2.1 volts to +4.2 volts for the 10dB range.
E. MAINTENANCE AND REPAIRS If the Model 140 is plugged into a standard power outlet through its power cord, the various display lights should light up at once when the On-Off button is pushed. If not, verify that the power outlet is live. The fuse should be checked. It is in the back of the instrument and can be found by removing the carrying case. The fuse is 0.75 amperes, type 3 AG. DO NOT REPLACE IT WITH A HIGHER RATING.
F. MODEL 141 MICPLEXOR 1. Description The Model 141 Micplexor is basically a microphone commutator. It is designed to accept the outputs from three dynamic microphones, amplify their signals to line level, and scan them at a rate determined to minimize the "aliasing" effect so as to present a spatial average of the sound field to the Model 140 Sound Analyzer. The output of the Micplexor is at a high level so that the signal may be transmitted to the Model 140 via a simple line pair.
e. MULTIPLEX-SINGLE Function The operation mode of the Model 141 may be selected via the MULTIPLEX-SINGLE switch on the front panel. In the SINGLE position, the output from either of the three microphone amplifiers may be selected. This allows the levels to be equalized via the CHANNEL GAIN slide potentiometers. The unit may also be used as a line amplifier for a single remote microphone by simply placing the MULTIPLEX-SINGLE switch in the SINGLE position and setting the MIC.
WARRANTY All products are guaranteed against defects in materials and workmanship for one year from date of shipment. Our warranty is limited to repairing or replacing any product which fails during the warranty period from normal use. We are not liable for consequential damages. Damage in Shipment Our Instruments are shipped with full insurance unless the buyer instructs othervise under his self-insurance. Prompt inspection should be made upon delivery and any necessary claims made against the carrier.
