Larson Davis CAL150 User Manual

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CAL150
Precision Acoustic Calibrator
Manual
Page 2
Page 3
I150.01 Rev E
Larson Davis
Manual
Page 4
Copyright
Copyright 2006-2015 by PCB Piezotronics, Inc. This manual is copyrighted, with all rights reserved. The manual may not be copied in whole or in part for any use without prior written consent of PCB Piezotronics, Inc.
Trademarks
PCB® is a registered trademark of PCB, Inc.
Disclaimer
The following paragraph does not apply in any state or country where such statements are not agreeable with local law:
Even though PCB Piezotronics, Inc. has reviewed its documentation, PCB Piezotronics, Inc. makes no warranty or representation, either expressed or implied, with respect to this instrument and documentation, its quality, performance, merchantability, or fitness for a particular purpose. This documentation is subject to change without notice, and should not be construed as a commitm ent or representation by PCB Piezotronics, Inc.
This publication may contain inaccuracies or typographical errors. PCB Piezotronics, Inc. will periodically update the material for inclusion in new editions. Changes and improvements to the information described in this manual may be made at any time.
Recycling
PCB Piezotronics, Inc. is an environmentally friendly organization and encourages our customers to
be environmentally conscious. When this product reaches its end of life, please recycle the product through a local recycling center or return the product to:
PCB Piezotronics, Inc. Attn: Recycling Coordinator 1681 West 820 North Provo, Utah, USA 84601-1341
where it will be accepted for disposal
Product Warranty
For warranty information, refer to our Terms and Conditions of Sale on our website at
www.larsondavis.com/TermsConditions.aspx.
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CAL150 Technical Reference Manual Introduction 1-1
CHAPTER
1
Introduction
This chapter describes the features and accessories of the Larson Davis CAL150 Sound Level Calibrator.
Features
The Larson Davis CAL150 Sound Level Calibrator is a battery-operated precision microphone calibrator used for the calibration of sound level meters and other sound measurement equipment. It can provide an output level of either 94.0 or 114.0 dB (switch-selectable) at a frequency of 1 kHz. It has been designed for both field and laboratory use and the accuracy has been calibrated to a reference traceable to the National Institute of Standards and Technology.
The Larson Davis CAL150 Sound Level Calibrator has the following features:
Class 2 sound level calibrator
Dual output levels: 94.0 dB and 114.0 dB (user selectable)
Output frequency 1 kHz
Internal batteries for portable operation
Opening for use with 1/2” microphones
Accessories
Adaptor ADP031 included for use with 3/8” microphones
Adaptor ADP024 available for use with 1/4” microphone
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CAL150 Technical Reference Manual Features 1-2
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CAL150 Technical Reference Manual Using the CAL150 Calibrator 2-1
CHAPTER
2
Using the CAL150
This chapterr describes the setup and operation of the CAL150.
Installing the Battery
The CAL150 uses a nine-volt battery and it is recommended that you use an alkaline battery to extend the running time of your calibrator. The CAL150 will run for approximately 100 hours on one nine-volt battery when using the 114 dB output level. This will give you nearly 4200 calibrations.
Follow the steps below to install the battery: Step 1 Slide the batt ery door on the lower section of the
back panel up to remove it.
Step 2 Gently pul l the batt ery connector clip sufficiently
outside the interior to permit it to be snapped onto the battery terminals.
Step 3 Tuck the battery, with the battery connector clip
attached, into the battery compartment.
Step 4 Slide the battery door back into place, pressing
until the tab snaps the door securely shut.
Microphone Calibration
The CAL150 provides a nominal tone of 1 kHz, which requires no weighting filter corrections when used with sound level meters utilizing A, B, C or Z (Flat) frequency weighting.
Selecting the Output Level
The output level is user-selected to be 94.0 or 114.0 dB using the slide selector on the side of the CAL150 . Slide the switch to lower position for 114.0 dB or to the upper
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CAL150 Technical Reference Manual Microphone Calibration 2-2
position for 94.0 dB, as indicated by the label on the lower left of the front panel.
Calibrating with ½" Free-Field Microphone Corrections
The CAL150 provides a nominal pressure level of 94 dB or 114 dB. The exact levels are printed on the Larson Davis calibration sheet that comes with the calibrator. When using a free-field microphone, the pressure level at the microphone diaphragm will be slightly different. Thus, a free field correction of -0.12 dB should be applied to either of these levels. Pressure and random incidence microphone do not require a correction of this type.
If the calibrator and instrument are near room temperature (23
°C) and near sea level (101.3 kPa) then no other corrections
need to be made. If the calibration sheet for the CAL150 indicates
113.98 dB for its level when set up to 114 dB then set the Cal Level
in the instrument to 113.86 dB and 1 kHz.
When the microphone and instrument are at a temperature other than near room temperature or static pressures not near sea level, then corrections will need to be added for the ambient temperature and the prevailing static pressure.
Check the calibration data shipped from Larson Davis with the CAL150 to get these corrections. The corrections can be added to get the actual level of the CAL150.
The microphone's sensitivity varies with static pressure. If the instrument is calibrated in one environment and moved to another, then the sensitivity will change (after stabilization) depending on the change of temperature and pressure. The coefficient of static pressure is typically -
0.013 dB/kPa for PCB ½" free-field microphones. If the
system is calibrated at 85 kPa, for instance, then it will be
0.21 dB less sensitive at sea level. The sensitivity of the
microphone varies slightly with temperature also. The coefficient of temperature is typically -0.009 dB/
°C for PCB ½" free-field microphones. If the system is calibrated at 18 °C then it will be 0.05 dB less sensitive at 23 °C.
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CAL150 Technical Reference Manual Microphone Calibration 2-3
Performing the Calibration
To calibrate the microphone, follow these steps: Step 1 Place the instrument so that you can perform the
calibration vertically, as shown in Figure 2-1.
WARNING! Do not remove the microphone gridcap during calibration as this may damage the microphone.
Step 2 Insert the proper microphone adapter fully into the
calibrator. Make sure it fits snugly.
Step 3 Insert the microphone fully into the adapter. Make
sure it fits snugly.
The preferred metho d for calibrating with the CAL150 is to mount the preamplifier in a fixed, vertical position.
FIGURE 2-1 Vertical Positioning
Top: calibrator stands vertically above mounted preamplifier.
Bottom: mounted preamplifier, fixed vertically
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CAL150 Technical Reference Manual Microphone Calibration 2-4
Step 4 With the microphone connected to the instrument
being calibrated, press the CAL150’s ON button. With a fresh battery, the calibrator will issue a tone for more than 60 seconds before automatically shutting off (see note below).
Step 5 Make a reading. If the reading is not with in
tolerance, refer to the instrument’s manual for instructions on how to adjust the instrument.
Step 6 Check the ambient noise level to insure that the
calibration was not influenced by noise from external sources. The CAL150 needs to be on the microphone but with the CAL150 signal off. External noise levels lower than 89 dB SPL for the 114 dB level calibration, and 69 dB SPL for the 94 dB calibration level will influence the calibration by less than 0.015 dB.
As the battery becomes weaker, the calibration tone will not deteriorate, but the operating time will decrease until the time is too short to accomplish an adequate calibration.
Each time the ON button is pressed, the CAL150 will run approximately 60 seconds on a fresh battery. Do not press the ON button again to turn it off. Wait until the calibrator times out. It is not an ON/OFF button.
When making a sequence of measurements, a calibration check and an adjustment (if necessary) of the instrument should be made at the beginning. At the end of the measurement sequence, the calibration should be checked again. The inaccuracy of the measurements will be at least as large as the difference between the level measured for the initial calibration (or calibration check) and the level measured for the final calibration check.
Calibration History
Larson Davis strongly recommends that a history of each calibration adjustment be kept for each piece of equipment. Normally, most modern equipment requires little or no adjustment once the initial calibration is performed. Systematic drifts are possible, and these should be recorded for corrective action.
Most Larson Davis sound level meters keep a history of each calibration change that can be printed before an overall reset. Please refer to the respective instrument manuals for details.
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CAL150 Technical Reference Manual Microphone Calibration 2-5
Environmental Precautions
While the CAL150 will perform normally under a wide variety of gradually changing environmental conditions, some precautions should be taken when sudden changes occur:
The temperature of the CAL150 should be stable. If the temperature changes suddenly, provide a stabilization time of at least 15 minutes. This will ensure that the temperature compensation sensors are at the same temperature as the rest of the unit.
While humidity will not affect the CAL150, avoid condensing moisture. Also, avoid environments over 90% relative humidity because condensation can easily take place.
The CAL150 is insensitive to magnetic fields. However, the instrument being tested may not be. Therefore, calibration should not be done near motors, dynamos, high voltage wires, or other sources of electromagnetic fields.
Calibrator Calibration
The American National Standards Institute states, “An acoustical calibrator should be recalibrated at least annually by the instrument manufacturer or an acoustical test laboratory qualified to perform calibration.” (American National Standards Institute. Specifications for Acoustical Calibrators. ANSI S1.40, 2006,par. 5.2)
Larson Davis believes the frequency of recalibration depends on the number of calibrators being used and the number of instruments being calibrated. With this in mind, the following guidelines are presented for your consideration:
For one calibrator and one measurement instrument , the CAL150 should be certified at least yearly.
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CAL150 Technical Reference Manual Microphone Calibration 2-6
If a systematic drift of several dB occurs, there is no reliable way to verify which instrument is at fault, even though it is more likely to be the measurement instrument.
For one calibrator and several measurement instruments, one calibration a year is recommended. But if no systematic drift occurs, every two years might be satisfactory.
For several calibrators and several instruments, one calibration a year is recommended.
If the CAL150 is being used to calibrate several instruments, then the history of calibration adjustments can usually pinpoint which instrument is drifting. If all the measurement instruments are drifting in the same direction b y an amount you consider significant, the CAL150 should be recertified.
If several instruments and several calibrators are in use, then the history of calibration adjustments would precisely pinpoint any problem pieces of equipment. Furthermore, it is probably satisfactory to recalibrate only one of the calibrators each year.
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CAL150 Technical Reference Manual Specifications A-1
APPENDIX
A
Specifications
The specifications contained in this chapter are subject to change without notice. Please refer to calibration and test results for data on a specific unit.
Standards Met
ANSI S1.40-2006, Specifications and Verification Proce­dures for Sound Calibrators, Class 2
IEC 60942-2003, Class 2, Sound Calibrators
IEC 61010-1:2001, Safety requirements for electrical equipment for measurement, control, and laboratory use
- Part 1 General Requirements
IEC 61326-1:2005, Electrical equipment for measure­ment, control, and laboratory use - EMC requirements
Technical Specifications
Calibration sound pressure level (factory specification)
Calibration sound pressure level after one year
94.0 dB and 114.0 dB ±0.3 dB SPL re: 20Pa @ 101.3 kPa, 23º C and 50 % RH (114.0 dB is the principal sound pressure level)
114.0 dB ± 0.3 dB under same conditions as above
Equivalent free-field level -0.12 dB for 1/2” free-field microphones
Frequency 1 kHz ± 1%
Harmonic distortion < 2 %
Stability after pressing On ± 0.1 dB after 2 seconds
Minimum stabilizing time after the microphone and calibrator are coupled together
10 seconds
Static pressure range 65 kPa to 108 kPa, SPL variation will be < ± 0.4 dB
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A-2 Technical Specifications CAL150 Technical Reference Manual
Table A-1 CAL150 Specifications
Microphone Types According to IEC 61094-4:1995
1/2” WS2P, WS2F and WS2D microphones; no adaptor required
Temperature range SPL variation < ± 0.6 dB Frequency variation < ± 2 Hz
over the range of -10 ºC to 50 ºC
Humidity range SPL variation < ± 0.5 dB over the range 10 % to 90 %
relative humidity (non-condensing) Frequency variation < ± 2 % over the range 10 % to 90 % relative humidity (non-condensing)
Storage temperature -40 ºC to 60 ºC
Storage humidity 0 % to 90 % relative humidity (non-condensing)
Effective volume of calibrator and microphone
4.15cm
3
(0.253 in.3 )
Dimensions Length 106.1 mm (4.18 in.)
Width 63.4 mm (2.5 in.) Thickness 25.9 mm (1.02 in.)
Weight 156 gm. (5.5 oz.)
Battery 9 V NEDA 1604A or IEC 6LR61. With sufficient battery
voltage, calibrator will run (after releasing ON button) for 1 to 1.5 minutes before automatic shutdown. With insufficient battery voltage, calibrator will not remain ON after release of button
Battery Voltage Operating Range 6.7 Volts to 10 Volts
Traceability Utilize a 1/2” precision condenser microphone (WS2P)
in conjunction with other traceable measuring instruments to establish traceability of the output level and frequency of the Model CAL150
CE-mark indicates compliance with EMC directive
Note: The reference orientation for testing the effects of radio-frequency fields is with the radio-frequency incident on the calibrator face and the electric field vector parallel to the axis of the microphone. This is also the orientation of maximum susceptibility and emissions
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CAL150 Technical Reference Manual Technical Specifications A-3
1/4” WS3P, WS3F and WS3D microphones with ADP024 adaptor
According to IEC 61094-1;2000
1/2” LS2P; no adaptor required
Other Microphones
3/8” with ADP031 adaptor
4180 Microphone
The CAL150 level correction is +0.26 dB
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A-4 Technical Specifications CAL150 Technical Reference Manual
CE Mark Declaration of Conformity
FIGURE A-1 CE Mark Declaration of Conformity
•PCB
Declaration
of Conformity
Application
of
Council
Directives:
2004/108/BC
EMC
Directive
and
2006/95/EC
Low
Voltage
Directive
Standards
to
which
Conformity
is
Declared:
C€
CE
- Mark indicates compliance
with
EMG
directive and
Low
Voltage
directive
2006/95/EC.
Harmonised
Standards
61326-1:2005
Electrical equipment for
measurement,
control,
and laboratory use - EMC requirements.
Safety requirements for electrical equipment for measurement, control, and
laboratory
use -
Part
1: General requirements.
Product Specific
standards
60942:2003
Sound Calibrators.
ANSI
.40-2006
Specifications
and
Verification Proceedures for
Sound
Calibrators.
Emissions
Test
Standards
CISPR
11: 4.1
2004:
Industrial, scientific
and
medical (ISM) radio-frequency
Electromagnetic
disturbance characteristics - Limits and methods of
measurement.
Class B, Group 1.
Immunity
Test
Standards
EC
Electrostatic discharge (ESD) immunity.
±4
kV contact discharges and ±8 kV air discharges.
Immunity
Test
Standards
Radiated, radio-frequency, electromagnetic field immunity.
80
1 V/m.
Immunity
Test
Standards
610004-8:2001
Power frequency magnetic
field
immunity. 80
A/m.
50/60
Hz.
Notes:
above are guaranteed only
when
using accessories listed
in
the product manual.
Manufacturer
PCB Piezotronics
3425
Walden Avenue
Depew,
New York USA
Authorized European Representative
PCB
Piezotronics Europe GmbH Porschestrasse
20-30
41836
Type
of
Equipment:
CAL150
-
Acoustic
Calibrator
the
undersigned,
hereby
declare
that the equipment specified
above
conforms
to the
above Directive(s)
and Standard(s).
Signature:
Name:
Kenneth
J.
Gonyea
Jr.
Title:
V.P.
Manufacturing
PS078(E)
03/13/2015
Depew,
NY
9001
PCB
Piezotronics,
Inc.
Plione:
716-684-0001
FAX:
716-684-0987
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