ACCULAB REFERENCE SOUND SOURCES
(TYPES RSS: 101, 300, 400, 500, 600 (Ultra Power) & 700 (Small Power))
For Use in the following Sound Power Measurement Methods:
ANSI 12.33, 12.34, 12.36
ISO 3743, 3744, 3746
AMCA 300
ASTM F1334

! NEW !
RSS 600 (Ultra Power) and RSS 700 (Small Power).
Open-Office Component Test Loudspeaker (OOLS).
Hemianechoic Room Test Loudspeaker (HALS)
OOLSA Pink Noise Amplifier for OOLS and HALS.

All Equipment Uniquely Designed for
Laboratory and Field
Noise Measurement Applications
Anywhere, any Time

2008 Information
 

RSS 101 (Click image for more information.)	RSS 400 (RSS 300 Similar) (Click image for more information.)	RSS 500 (Click image for more information.)
RSS 600 (Click image for more information.)	RSS 700 (Clickimage  for more information.)	RSS 101U (Click image for more information.
Ship & Carry Case for RSS 101, 101U, 300, 400, 700	RSS 102 (Click image for more information.)	Ship & Carry Case for RSS 500, 600.
The ultimate in field utility! One-hand carry; about 37# total with RSS. Ship anywhere. Store indefiitely. Ready instantly		Ship anywhere. Store indefiitely. Ready instantly
=========================================== ACCULAB OPEN OFFICE TEST LOUDSPEAKER   per ASTM 1179 for ASTM 1111 =========================================== Office test sound source	================================== HEMIANECHOIC SPACE TEST LOUDSPEAKER For ISO 3745, ANSI 12.35 ==================================  Hemi-anechoic test sound sourc	================================== Loudspeaker Pink Noise Source & Amplifier For OOLS and HALS ================================== Office test sound source
OOLS (Clickimage  for more information.)	HALS (Click image for more information.)	OOLSA-1105 (Click image for more information.)

Specifications
Unpacking / Acoustical Application
Hemianechoic Calibration Data
Packing / Shipping / Parts List
Prices

    NOTE 1: The device called a "reference sound source" is used throughout industry and engineering where it is necessary to determine the amount of noise (sound power) that is emitted by a device (fan, vacuum cleaner, engine, etc.) into the surrounding environment. Though it is possible to do so by extensive sound level measurements in a controlled (lab) environment, such a process is tedious and uncertain without extensive calibrated acoustical equipment and certified procedures.

On the other hand, the much simpler "substitution (comparison) method" is possible, where the device under test (DUT) is operated in its natural environment while conventional sound pressure level (SPL) measurements are made around the DUT. The DUT is then shut off. The  "Reference Sound Source" (RSS) is placed next to the inoperative DUT, switched on, and the SPL is again measured in the same way as before. The RSS sound power output has previously been calibrated by precise methods, so the sound power of the device under test is simply calculated as

DUT.PWL = DUT.SPL - RSS.SPL + RSS.CAL ,      dB re one Picowatt.

[One Picowatt = 10^(-12) watts.]

    CALIBRATION FREQUENCY RANGE: Such sound power can be measured at all audio frequencies, typically in 1/3 octave bands separately. A distinct advantage of our ACCULAB reference sound sources is that they are of stable sound power emission over an extremely wide frequency range. In addition, we calibrate (Hemianechoic outdoors) all our RSS units outdoors, where there is no lower frequency limit, on request, from 12.5 Hz through 20,000 Hz. (Conventional indoor laboratories are restricted in size so that  data below 100 Hz are difficult to impossible to produce, though several such laboratories now produce data to as low as 50 Hz) .

  Our original unit (starting circa 1982), the RSS101, is for use on 60 Hz alternating current common in North America. A 50 Hz, 220vac unit, the ACCULAB RSS 300 is also available, which can also operate (special order) on 110vac.

    NOTE 2: In recent years, sound power measurement with the INTENSITY method has become increasingly important. ISO 9614, parts 1 and 2 now address this measurement. Ostensibly, it should be immune to background noise to an extent. It was at first implied that a reference sound source was then not needed. But in reality, the intensity method requires a special probe having two identical microphones, a complex analog/digital signal processor, software algorithms that are in themselves complex. In addition, microphone spacing must be changed at least once to measure sound power over a wide frequency range. Not all operators and technicians are experienced in handling all of these parameters.

    The practical result is that despite the fact that one may have expended a great deal of time, money and travel efforts to set up an intensity sound power test, the credibility and reliability of the results can come into question. Therefore, it has become prudent to maintain a reference sound source such as the RSS101 on hand ether at the home office or in the field for routine "Validation" of hardware, software, and scanning technique elements on-site. To wit: The sound power deduced by the intensity apparatus + software setup + scan method when applied to the RSS as a DUT shall match the RSS101 calibration values within 1 dB from 100 Hz through 5,000 Hz. If there is a discrepancy, the intensity apparatus, etc. is at fault. i.e. the RSS acts as a 3 dimensional "pistonphone"!

    The Hemianechoic Calibration following shows such RSS.CAL information for a typical ACCULAB RSS 101.

Sound Power Output Uniformity (Typical - RSS Type 101) hemianechoic Calibration:

A-Weighted = 86 dB re 1 Picowatt (See RSS-101 Embossed Tag)
Full Octave Level = 79 + 2 dB re 1 Picowatt (63 to 4,000 Hz)
1/3 Octave level = 73.5 + 3.5 dB re 1 Picowatt (50 to 5,000 Hz)
[Sound Power Levels are Constant and Usable from 12.5 Hz through 20,000 Hz]
For frequencies above 20,000 Hz see the Ultrasonic RSS.

Features (All RSS Units):

• Omnidirectional
  
• Protective Frame
  
• Ruggedized Fan Wheel
  
• Carrying Handle
  
• Isolator Friction Feet
  
• (Per ANSI S1.31 1980)
  
• Instant Start
  
• Drip-Proof Motor
  
• Wheel Key

Physical:

Size: 240 x 240 x 410 mm (10" x 10" x 16")
Weight: 11 kg (24 lbs)
Power: 115 VAC 1 ph, 60* Hz. (750 V A )
Color: Olive - (special on request)

For Additional Information:

PHONE  6 1 4 - 8 7 6 - 5 1 0 8
FAX       6 1 4 - 7 7 1 - 8 7 4 0
Cell       6 1 4 - 5 6 0 - 0 5 1 9

    OPERATING INSTRUCTIONS:

    GENERAL

    The Reference Sound Source is shipped ready for use after unpacking. Precautions, calibration and acoustical application notes are as follows.

    UNPACKING

    Before placing the RSS-101 into use, please observe the following precautions.

1. Remove the RSS-101 from the corrugated Kraft board container by pulling upward by its frame (5/16" rods and also cross-bar with spiral-wrap). Preserve container, foam pads and shipping sleeve for subsequent use. (Pads or side position unload resilient feet during long term storage).

2. Place it upright on its rubber feet on a firm floor or bench.

3. Remove the shipping sleeve. (Similar support devices should be used when shipping the RSS- 101 0792 to distant locations.)

4. Inspect Fan wheel for uniformity and firmness of shaft attachment. Use 4 mm Allen key supplied to torque both wheel hub set screws to 30 inch-pounds if in doubt. (Access Allen screw heads between fan wheel blades). Verify fan wheel serial number as " " written inside fan wheel hole near the hub.

1. Set the RSS-101 on its feet at the desired location. Maintain its spacing from vertical surfaces according to the applicable acoustical test requirements.

2. The floor under the RSS-101 should be firm and not prone to act as a "sounding board" which can cause spurious sounds. Our new spring-isloated feet minimizes this to the extent that is is no longer a problem in most situations. If such spurious action is still suspected (on very thin sheet metal panels), Place a layer of 3/4" plywood at least 1m round or square under the RSS101, or move it to a firm location. If the RSS-101 is set on an elevated flat horizontal surface, that surface should be at least 3' (1m) square or round to assure that the calibrated sound power is emitted into the test area.

3. Maintain fingers well clear of fan wheel. Clear a 5' diameter area of dust and loose paper objects since air flows out of the fan wheel perimeter onto the room floor during normal RSS-101 operation.

4. Plug into 115 VAC, 60 Hz, single phase power (grounded pin receptacle). Fan will start immediately. Extension cord length vs minimum wire size: 100'- #16; 200'-#14. Check RPM with a photo-tachometer. RPM should be between 3530 and 3550. If it is less than 3520, then the a.c. line voltage is too low or the extension cord must be shorter or of heavier gage wire. Operation at 3510 rpm may be used provided 0.25 dB are subtracted from all calibration data values (according to a 50*Log(3545/RPM) correction rate).

5. Note: International 50 Hz RPM values range from 2910-2940 RPM.

6. Operation may be continuous for ambient air temperatures below 40° C. Run acoustical tests. Calibration data is on the next page or the current certification report or other generic data appended to this manual.

7. Disconnect the RSS-101 from electrical power when you are not actually producing acoustical test data to avoid inadvertent damage to fan wheel.

8. Replace RSS-101 in its shipping container when not in use. (Storage on its side, or supported by the box-bottom pad will unload and prevent distortion of the resilient feet during long-term storage).

9. Similar methods and precautions apply to all other RSS units (102, 300, 400, 500, 600, 700).

See price list.

See price list.
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    The RSS-600 will produce a constant sound field indefinitely as long as proper power is applied and the calibration RPM is achieved. However, significant fan wheel distortions and dust accumulation can alter the sound output. Dust can be removed with a dry clean brush. Substantial fan wheel distortions that have been repaired will alter the sound field, and recalibration is advised. This can be done by an acoustical sound power testing laboratory according to ISO 6296 or ANSI 12.5.

See price list.
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See price list.
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RSS 102 "Ilg" Simulation Reference Sound source Someone once asked us to provide a replacement for their old damaged Ilg Fan. So we layed our RSS101 on its side, grafted appropriate feet to mantain floor spacing, then added our protective frame and carrying handle for convenience... this was the result.

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RSS 101U

RSS 101U Air Ultrasound reference Sound source (ANSI 1.26)

 

We produce this special reference sound source for air ultrasound to meet the needs of manufacturers of ultrasound detectors such as leak detectors and motion sensors. This RSS 101U will produce calibrated intensity from 10 kHz through 100 kHz. It provides a steady and reliable ultrasound field that is also useful for calibration of ultrasound microphones by the substitution (comparison) method of ANSI 1.26. A distinct advantage of substitution (comparison) calibration of microphones in this RSS101U broad band sound field is that the broad band sound, even just 1 kHz wide,  eliminates the "Ripple" or Scalloping" effect of coherent ("pure tone") sound waves spawned by nearby jigs and fixtures.

RSS 101U (Click for more information.

This RSS 101U produces a cylindrical source of ultrasound 3 inches (75mm) high and 6" (150mm) wide, Omnidirectional in all azimuth directions. Test microphones are usually positioned 1/2m from the source. There, in the 10-20 kHz frequency range, will be found broad band ultrasound having a sound pressure level of about 60  re dB re 20 micropascals, per kHz of bandwidth. This sound field diminishes to about 50 dB in a one kHz band at 50 kHz, to 34 dB in a one kHz band at 100 kHz. .  It operated on 115vac, 60 Hz. It may operate at 50 Hz with a lower sound power emission. Physical size and weight is the same as our RSS101.

ULTRASONIC ANECHOIC CALIBRATION: RSS Type 101U (0597) S/N No. 07 92 235U Accuracy:  +1 dB @ 1 kHz to 80 kHz : //////// +2 dB @ 81 kHz to 100 kHz     The RSS 101U is specially designed to produce reliable and steady broad band ultrasound in air at frequencies above from ten kilohertz to 100 kHz and higher. Calibration is performed at a distance of 0.5m from the axis of the ultrasound cylinder wheel. Calibration data are taken with a 100-line FFT. Hanning* window, 1 kHz wide, located in 1 kHz steps from 1 to 100 kHz.     *(A Rectangular FFT Window provides parity for energy anywhere in the window band, but leaks sound outside that band.) For reporting the calibration spectrum of th broad band sound emitted, the FFT Hanning Window is used because it prevents most energy leakage outside of the designated band. This Hanning window also reports a value that is 1.76 dB greater than that reported by a Rectangular FFT Window. This fact is indicated in the Claibration report. See: B&K Technical Review, 1987 issue 3, page 13. Typical ultrasound RSS101U sound emission values* are: .

FFT Window Lower   Freq, kHz	1Khz Band Sound Pressure Level*   @ o.5m, dB re 20 uPa	FFT Window Lower   Freq, kHz	1Khz Band Sound Pressure Level*    @ o.5m, dB re 20 uPa
5 10 15 20 30 40	62 59 63 59 56 51	50 60 70 80 90 100	48 45 42 39 36 34

    (1) Calibration was performed 1 November 2005 at an ultrasonic anechoic indoor site per (ANSI S1.4) at a horizontal distance of 20 inches (0.5 m) from the fan wheel centerline and at a single microphone position. The measurement microphone was a Larson-Davis type 2520 S/N 1473 with its protective grid removed and corrected to free-field conditions. Measurement data were corrected for air & humidity attenuation. Air temperature was 19 C (67 F), Air Humidity = 45%, Air pressure = 993 mB (745 mmHg). RSS101U RPM = 3555+-1 RPM at a supply frequency of 60 Hz and a line voltage of 120 vac at the RSS plug.

    (2) These data may be used to calibrate the response of ultrasonic acoustical receivers positioned in the plane of the fan wheel at 0.5m (20") from the center of the fan wheel. The acoustical energy apportioned to the response is calculated from the bandwidth, B, of your signal receiver (Hz between "3db down" response frequencies) as follows:

SPL received @ 20" = cal SPL - 1.67*A+ 10Log[(B/1000) dB re 2*10-5 Pascals.

    The calibrated SPL is then chosen from the above table for the frequency that is the center of the frequency range of bandwidth, B. The value of A is found from page 6 (humidity). If B is more than 5,000 Hz, then individual 1,000 Hz band calibrated levels shall be decibel-summed to provide the energy received by the receiver.

    (3) If the receiver is placed at greater distances (more than 0.5m or 20"),   the calibrated SPL level should be re-computed according to

test SPL = cal SPL - 20*Log[2*D] - 3.3*D*A dB re 2*-5 Pascals.

where D is the distance in meters, and A is found in the graph on page 6 for the test site air humidity and approximate temperature.         
  rev 08-99

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    In case of any difficulties, contact ACCULAB (614)\876-5108 (A.J. Campanella) for further help and instructions. If it is necessary to ship the RSS-101 anywhere, or to return it to ACCULAB, proceed as follows: 1/Do NOT load this bare-framed instrument surrounded by only bubbles or pellets, as the fan wheel can be damaged in this environment. Rather, 2/Place the source unit in a close fitting corrugated Kraft box as originally shipped, then 3/Install shipping stabilizer corner strips, top & bottom blocks to support the perimeter of the exterior frame, and a cardboard shim between the fan and the motor bearing boss. (If you expect abusive shipment, place this box in a larger container with cushioning foam, bubbles or pellets, though this precaution is usually unnecessary for domestic US shipment, since the reinforced steel frame is also a sturdy shipping container.) Seal and ship by Air Freight, UPS or US Parcel Post

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