Rion NL-42A User manual

3-20-41 Higashimotomachi, Kokubunji, Tokyo 185-8533, Japan
https://www.rion.co.jp/english/
INSTRUCTION MANUAL
Sound Level Meter
NL-42A / NL-52A

i
Organization of the NL-42A/NL-52A documentation
Documentation for the Sound Level Meter NL-42A/NL-52A comes in three
parts, as listed below.
Instruction Manual (this document)
Describes operating procedures for the NL-42A/NL-52A, connection and
use of peripheral equipment such as a level recorder and printer, and use
of the SD memory card.
Serial Interface Manual
Describes communication with a computer, using the serial interface built
into the NL-42A/NL-52A. The manual covers the communication protocol,
use of control commands for the sound level meter, format of data output
by the sound level meter, and other topics.
Technical Notes
This document provides in-depth information about sound level meter
performance, microphone construction and characteristics, inuence of
extension cables and windscreen on the measurement, and other topics.
The current instruction manual is available on our website.
(https://www.rion.co.jp/english/)
* Company names and product names mentioned in this manual are usually
trademarks or registered trademarks of their respective owners.

ii

iii
Organization of this manual
This manual describes the features, operation and other aspects of the NL-42A/
NL-52A. If the unit is used together with other equipment to congure a mea-
surement system, consult the documentation of all other components as well.
Pages v and following contain important information about safety. Be sure to
read and observe these in full.
This manual contains the following sections.
Outline
Gives basic information about the unit.
Controls and Functions
Briey identies and explains the operation keys and connectors and all
other parts of the unit.
Preparations
Explains how to check the unit before use and how to install and set up the
unit for measurement.
Calibration
Explains how to calibrate the unit for measurement.
Reading the Display
Explains symbols and other information shown on the display of the unit.
Measurement
Explains the basic procedures for measurement.
Card capacity and store time
Lists the data store time corresponding to the SD memory card capacity, etc.
Store Operation
Explains how to store measurement data.

iv
Input/Output Connectors
Explains the input and output connectors of the unit.
Default Settings
Lists the factory default settings of the unit.
Setup Files
Explains how to start up the unit using settings saved in a setup le.
Optional Accessories
Explains how to use the optional microphone extension cable, printer, and
level recorder with the unit.
Specications
Lists the technical specications of the unit.

v
FOR SAFETY
In this manual, important safety instructions are specially marked as shown
below. To prevent the risk of death or injury to persons and severe damage
to the unit or peripheral equipment, make sure that all instructions are fully
understood and observed.
Caution
Important
Disregarding instructions printed
here incurs the risk of damage to
the unit.
Additional information about
using the unit. (These notes do
not directly affect safety.)
Note
WARNING Disregarding instructions printed
here incurs the risk of death or
severe injury to persons.
Disregarding instructions printed
here incurs the risk of injury to
persons and/or damage to periph-
eral equipment.

vi

vii
Quantier Notation
(Sound level and sound pressure level are expressed uniformly as sound
pressure level, distinguished by the use of frequency weighting.)
Measurement value
The time weighting characteristics
F, S I
Lp
Sound pressure
level
A-weighted sound pressure level LAF, LAS LAI
C-weighted sound pressure level LCF, LCS (LCI)
Z-weighted sound pressure level LZF, LZS (LZI)
Leq
Equivalent
continuous
sound level
Equivalent continuous A-weighted
sound level LAeq LAIeq
Equivalent continuous C-weighted
sound level LCeq (LCIeq)
Equivalent continuous Z-weighted
sound level LZeq (LZIeq)
LE
Sound exposure
level
A-weighted sound exposure level LAE(LAIE)
C-weighted sound exposure level LCE(LCIE)
Z-weighted sound exposure level LZE(LZIE)
Lmax,Lmin
Maximum sound
level
Maximum A-weighted sound level LAFmax, LASmax LAImax
Maximum C-weighted sound level LCFmax, LCSmax (LCImax)
Maximum Z-weighted sound level LZFmax, LZSmax (LZImax)
LN
Percentile sound
level
Percentile A-weighted sound level LAFNn, LASNn(LAINn)
Percentile C-weighted sound level LCFNn, LCSNn(LCINn)
Percentile Z-weighted sound level LZFNn, LZSNn(LZINn)
Lpeak
Peak sound level
A-weighted peak sound level (LApeak) ---
C-weighted peak sound level LCpeak ---
Z-weighted peak sound level LZpeak ---
Ltm5
Takt-max sound
level
Takt-max A-weighted sound level LAtm5 ---
Takt-max C-weighted sound level (LCtm5) ---
Takt-max Z-weighted sound level (LZtm5) ---
• Z-weighted level is the same as an existing at-weighted level.
• The combination of peak sound level and takt-max with I character-
istics does not exist.
• Generally, measurement value shown in brackets ( ) are not used or
not suitable for evaluation.

viii

ix
Quantier Notation of NL-42A/NL-52A According to International Stan-
dards and JIS
(Excerpts from ISO 1996, ISO 3891, IEC 61672-1, JIS Z 8202, JIS Z 8731)
NL-42A/52A
notation Description Frequency
weighting
ISO
notation
IEC
notation
JIS
notation
LZSound level ZLp—Lp
LAA-weighted sound level ALpA—LpA
LCC-weighted sound level C———
LZeq
Equivalent continuous
sound level Z———
LAeq
Equivalent continuous
A-weighted sound level ALAeq,TLAeq,TLAeq,T
LCeq
Equivalent continuous
C-weighted sound level C—LCeq,T—
LZESound exposure level Z———
LAE
A-weighted sound
exposure level ALAELAE,TLAE
LCE
C-weighted sound
exposure level C———
LAN
LA5
Percentile A-weighted
sound level ALAN,T
LA5,T—
LAN,T
LA5,T
LA10 LA10,T—LA10,T
LA50 LA50,T—LA50,T
LA90 LA90,T—LA90,T
LA95 LA95,T—LA95,T
LAmax
Maximum A-weighted
sound level A———
LAmin
Minimum A-weighted
sound level A———
LCpeak
C-weighted peak sound
level C—LCpeak —
• Z-weighted level is the same as an existing at-weighted level.

x
Precautions
Operate the unit only as described in this manual.
The NL-42A/NL-52A is a precision instrument. Protect it from shocks
and vibrations. Take special care not to touch the microphone diaphragm.
The diaphragm is a very thin metal lm which can easily be damaged.
Use only the microphone/preamplier assembly with the number as shown
on the name plate of the unit.
Do not use the preamplier of this unit with sound level meters of other
models. It may cause the preamplier to fail.
Ambient conditions for operation of the unit are as follows: temperature
range −10°C to +50°C, relative humidity 10% to 90% RH. Protect the
unit from water, dust, extreme temperatures, humidity, and direct sunlight
during storage. Also keep the unit away from air with high salt or sulphur
content, gases, and stored chemicals during storage and use.
If it starts raining while using the unit outside, stop the measurement and
protect the unit from getting wet. In case the unit gets wet, wipe it with
a dry cloth and let it dry in a well-ventilated place.
The power cord used to connect the optional AC adapter to an AC outlet
is a 100 V AC cord for domestic use in Japan, which is compliant with
Japanese laws and electrical safety standards. Do not use this power cord
outside Japan or with any voltage other than 100 V AC. Otherwise, RION
cannot guarantee the safety of the equipment. Use a power cable that is
compliant with the laws and electrical safety standards of your location.
If you notice any sign of a problem during use, disconnect the AC adapter,
remove the battery, and contact your supplier.
Always turn the unit off after use. Remove the batteries from the unit
if it is not to be used for a long time. Otherwise battery uid may leak,
posing a risk of corrosion and damage. Also disconnect the AC adapter
or battery pack.
When disconnecting cables, always grasp the plug and do not pull the
cable.
Before using the unit and before putting it away, always check that the
microphone and microphone grid has not become loose. If this has happened,
refasten the microphone grid rmly and then use or store the unit.
Store this unit in the right place in the supplied storage case.

xi
Up to two units can be stored in the storage case. When storing the unit in
an empty space, protect the unit by wrapping it with cushioning material.
Note that we are not responsible for any failure or damage to the unit which
occurs while the unit is stored in an empty space.
Clean the unit only by wiping it with a soft, dry cloth or, when necessary,
with a cloth lightly moistened with water. Do not use any solvents, cleaning
alcohol or chemical cleaning agents.
Do not try to disassemble or alter the unit. In case of an apparent mal-
function, do not attempt any repairs. Note the condition of the unit clearly
and contact the supplier.
Do not tap the LCD panel or other surfaces of the unit with a pointed
object such as a pencil, screwdriver, etc.
Take care that no conductive objects such as wire, metal scraps, conductive
plastics etc. can get into the unit.
To ensure continued accuracy, have the unit checked and serviced at
regular intervals. Contact the supplier.
Dispose of the unit and of batteries only according to national and local
regulations at the place of use.
Do not remove the seal on the rear of the unit. If the seal is removed, the
“water and dust resistant performance” of the unit is no longer guaranteed.
In order to maintain the “water and dust resistant performance” of the
unit, observe the following precautions.
- Make sure that the battery compartment lid and bottom cover of the
unit are rmly closed.
- Do not open the battery compartment lid or bottom cover while the
unit is wet.
- Do not leave the unit in a wet state. Always wipe off any moisture
and properly dry the unit.
- Have the unit regularly checked and calibrated, to ensure continued
“water and dust resistant performance”.
- We recommend to have the packing inside the case and the bottom
cover replaced regularly (fare-paying service). The recommended
replacement cycle is ve years. If more than two years have elapsed,
the “water and dust resistant performance” of the unit will no longer
be guaranteed. Regarding replacement of the packing and the bottom
cover, please contact your supplier.

xii
The life of the backup battery for the internal clock of the unit is lim-
ited. You should have the battery replaced about once every ve years.
Regarding replacement of the battery, please contact your supplier.
Please note that this product is warranted up to the product purchase price
against defects in material.
Never format optional program cards such as the NX-42EX and NX-42WR
with SD memory card formatting software (such as SD Formatter, etc.).
Otherwise the program data on the card will be erased and the respective
functions can no longer be used. Restoration of the erased program is not
warranted.
This product can be used in any areas including residential areas.

xiii
Contents
FOR SAFETY.................................................................................v
Outline ............................................................................................1
Controls and Functions....................................................................5
Front view..................................................................................5
Bottom view ..............................................................................8
Rear view...................................................................................9
Preparations ..................................................................................10
Power.......................................................................................10
Power on/off ............................................................................14
Windscreen (WS-10, WS-15, WS-16).......................................16
Diffuse sound eld correction..................................................17
SD memory card and program cards........................................ 18
Microphone extension cables (EC-04 series)............................19
Tripod mounting ......................................................................21
Connection to a printer (DPU-414) ..........................................22
Connection to a level recorder (LR-07, LR-20A) and
data recorder (DA-20, DA-21, DA-40)......................................24
Connection to a computer .......................................................25
Setting the date and time .........................................................26
Measurement in a dark location ...............................................27
Sub channel settings ................................................................29
Eco setting (Power-saving mode) .............................................32
Comparator output ...................................................................33
Language selection ..................................................................36
Calibration ....................................................................................37
Internal calibration (Electrical calibration) ..............................37
Acoustic calibration (with Sound Calibrator NC-75/NC-74 or
Pistonphone NC-72B/NC-72A).................................................39
Reading the Display ...................................................................... 41
Measurement screen display .................................................... 41
Sub channel display screen ......................................................46

xiv
Processed data display screen other than Lpvalue ...................46
Time-Level screen ...................................................................47
Indicator messages...................................................................48
Menu list screen.......................................................................49
System (Language) ............................................................. 51
Display ...............................................................................54
I/O......................................................................................57
Store...................................................................................59
Measure..............................................................................62
LN Mode............................................................................64
Save/Print...........................................................................65
Option ................................................................................66
Recall.................................................................................67
WR.....................................................................................70
MENU list items ................................................................71
Measurement.................................................................................72
Sound level (Lp) measurement..................................................72
Equivalent continuous sound level (Leq) measurement .............74
Sound exposure level (LAE), Maximum sound level (Lmax),
Minimum sound level (Lmin) and Percentile sound level (LN)
measurement .................................................................................79
Additional processing value measurement ...............................80
Card capacity and store time .........................................................83
Using Auto store (when the NX-42EX is installed)..................83
When performing waveform recording
(when the NX-42WR is installed) ............................................84
Store Operation .............................................................................85
Manual mode operation ...........................................................88
Auto mode operation................................................................92
Marker.....................................................................................95
Timer Auto mode operation .....................................................97
Data size information............................................................. 102
About the store data format....................................................102
About SD memory cards........................................................102

xv
Formatting an SD memory card.............................................104
Screen hard copy .................................................................. 105
Input/Output Connectors ............................................................. 106
AC OUT connector................................................................106
DC OUT connector................................................................ 108
I/O connector......................................................................... 110
Default Settings........................................................................... 111
Setup Files .................................................................................. 113
Resume function .................................................................... 113
Loading a start up le at startup ............................................ 113
Restoring default settings (factory default settings) ................ 114
Using setup les..................................................................... 115
Setting a start up le.............................................................. 118
Optional Accessories................................................................... 119
Microphone extension cables (EC-04 series).......................... 119
Printer DPU-414 ....................................................................120
Level recorder LR-07/LR-20A ...............................................123
Program options ....................................................................125
Specications ..............................................................................126

xvi

1
Outline
The Sound Level Meter NL-42A and NL-52A are designed for sound level
measurements according to the IEC standard. They support diffuse sound
eld measurements and also meets standard requirements when the supplied
windscreen is mounted.
The NL-42A and NL-52A consist of the 1/2-inch electret condenser micro-
phone UC-52 (for NL-42A) and UC-59 (for NL-52A), preamplier NH-24
(for NL-42A) and NH-25 (for NL-52A), and the main unit. The preamplier
can be used by separating and extending from the main body. The unit is
equipped with the operation keys and 2.8-inch backlit semitransparent color
TFT LCD display to offer good visibility for indoor/outdoor use and also in
a dark location.
The display supports various languages, and enables user-friendly, intuitive
operation which can be operated comfortably by persons who are inexperi-
enced in measurements.
The unit is equipped with AC OUT and DC OUT connector, I/O connector
and USB connector as the output connectors.
Since the main unit offers the “water and dust resistant performance” equivalent
to IP54 (except microphone unit), outdoor measurements can be performed
without undue worries and a risk of failure caused by a sudden rain can be
reduced.
The 113 dB wide linearity range enables measurement without switching ranges.
Measurement results data are stored on the internal memory or inserted SD
memory card of the unit.
The unit is designed for power saving, so operates continuously for up to 24 hours
on four size AA batteries.
Also, in consideration of environment, nickel metal hydride rechargeable bat-
teries can be used to help reduce the amount of battery waste.
Connecting to an external power is also possible. And the unit can be connected
the external power supply for the long time measurement.

2
Outline
Communication with a computer is possible via the built-in I/O connector
and USB connector. Because the USB connector conforms to storage spec-
ications, the unit will be recognized as a removable disk when connected
to a computer. This allows transfer of data from the SD memory card to the
computer without having to remove the SD memory card from the unit.
The RS-232C interface allows sending measurement data to a printer.
Various optional programs allow users to add the following functions: long-
time, continuous data recording to SD memory card, waveform recording,
and comparator output. Also, various measurements are supported including
octave and 1/3 octave band real-time analyses, FFT analysis, and additional
measurements such as time weighting I (impulse).
In addition to the measurements of sound level, equivalent continuous sound
level and maximum/minimum sound level, the unit can measure percentile
sound level and sound exposure level. Up to 1000 measurement results can
be stored in the main unit.
The NL-42A/NL-52A allows the following quantity measurements.
Main processing
Simultaneous measurement of all items with selected time weighting (F,
S) and frequency weighting (A, C, Z) characteristics
Instantaneous sound pressure level Lp
Equivalent continuous sound pressure level
Leq
Sound exposure level LE
Maximum sound pressure level Lmax
Minimum sound pressure level Lmin
Percentile sound level LN1, LN2, LN3, LN4
(1 to 99, 1-increment steps)
LN5 (0.1 to 99.9, 0.1-increment
steps)