Larson Davis CAL150 User manual

CAL150
Precision Acoustic Calibrator
Manual

I150.01 Rev E
Larson Davis
CAL150
Manual

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 commitment 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.

CAL150 Technical Reference Manual Introduction 1-1
CHAPTER
1Introduction
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

CAL150 Technical Reference Manual Features 1-2

CAL150 Technical Reference Manual Using the CAL150 Calibrator 2-1
CHAPTER
2Using 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 battery door on the lower section of the
back panel up to remove it.
Step 2 Gently pull the battery 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

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.

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 method 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

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 within
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.

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.

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 by 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.

CAL150 Technical Reference Manual Specifications A-1
APPENDIX
ASpecifications
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 Proce-
dures 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 measure-
ment, 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: 20Pa @ 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

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 4.15cm3 (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

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

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) andStandard(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: [phone]