Rion NA-27 User manual

INSTRUCTION MANUAL
Precision Integrating Sound Level Meter
with 1/3 octave band real-time analyzer
NA-27
3-20-41 Higashimotomachi, Kokubunji, Tokyo 185-8533, Japan
http://www.rion.co.jp/english/

i
Organization of This Manual
This manual describes the features, operation and other aspects of the Precision Integrating
Sound Level Meter with 1/3 octave band real-time analyzer NA-27. If the unit is used together
with other equipment to configure a measurement system, consult the documentation of all
other components as well. The following pages 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. Also contains information about items that are
not covered in other sections.
Controls and Functions
Briefly identifies and explains the controls and connectors and all other parts of the unit.
Preparations
Explains how to insert the backup battery and main batteries, how to make connections,
set the date and time, calibrate the unit, and use the menu screens.
Setting Measurement Parameters
Explains how set the basic parameters before starting sound pressure level measurement
and analysis.
Sound Pressure Level Measurement
Explains the operation steps for performing sound pressure level measurement.
1/1-Octave and 1/3-Octave Analysis
Explains the operation steps for performing 1/1 and 1/3 octave analysis.
Data Exclusion (Back-Erase) Function
Explains how to exclude (back-erase) data from a short period before the measurement
was paused.
Trigger Function
Explains how to start the sound pressure level measurement using the trigger mode.
Delayed Measurement
Explains how to perform delayed measurement.
Memory Functions
Explains how to store measurement results in the memory of the unit.

ii
Remote Control (NA-27RC1)
Explains the names and functions of the operation buttons on the panel of the remote
control.
Technical Notes
Provides information about the microphone, preamplifier, basic configuration of the sound
level meter, and measurement functions.
Error Messages
Lists error message that can appear during startup, as well as suitable countermeasures.
Optional Accessories
Explains how to use the optional accessories available for the unit.
Specifications
Lists the technical specifications of the unit.
To conform to the EU requirement of the Directive
2002/96/EC on Waste Electrical and Electronic
Equipment, the symbol mark on the right is shown
on the instrument.
The NA-27 described in this manual is in conformity with the
following International Standard;
IEC 61672 - 1:2002 Class1 (Sound level meter)
EMC DIRECTIVE
* Company names and product names mentioned in this manual are usually trademarks or
registered trademarks of their respective owners.

iii
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 product.
Disregarding instructions
printed here incurs the risk of
injury to persons and/or dam-
age to peripheral equipment.
Mentioned about the tips to use
this unit properly. (This mes-
sages do not have to do with
safety.)
Note
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iv

v
Precautions
zOperate the unit only as described in this manual.
zThe NA-27 is a precision instrument. Protect it from shocks and vibrations. Take spe-
cial care not to touch the microphone diaphragm. The diaphragm is a very thin metal
film which can easily be damaged.
zUse only the microphone/preamplifier assembly with the number as shown on the
name plate of the unit.
zAmbient conditions for operation of the unit are as follows: temperature range -10 to
+50ºC, relative humidity 30 to 90%.
Protect the unit from water, dust, extreme temperatures, humidity, and direct sunlight
during storage and use. Also keep the unit away from air with high salt or sulphur
content, gases, and stored chemicals.
zAlways turn the unit off after use. Remove the batteries from the unit if it is not to be
used for a long time (a week or more). When disconnecting cables, always grasp the
plug and do not pull the cable.
zBefore using the microphone and before putting it away, always check that the micro-
phone grid has not become loose. If this has happened, refasten the microphone grid
firmly and then use or store the microphone.
zClean 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.
zDo not tap the LCD panel or other surfaces of the unit with a pointed object such as a
pencil, screwdriver, etc.
zTake care that no conductive objects such as wire, metal scraps, conductive plastics
etc. can get into the unit.
zDo not try to disassemble or alter the unit. Otherwise type certification will become
invalid. In case of an apparent malfunction, do not attempt any repairs. Note the condi-
tion of the unit clearly and contact the supplier.
zTo ensure continued precision, have the unit checked and serviced at regular intervals.
zWhen disposing of the unit or the accessories, follow national and local regulations
regarding waste disposal.

vi
Contents
FOR SAFETY ...................................................................................................iii
Outline................................................................................................................ 1
Controls and Functions.................................................................................. 4
Carrying Case and Accessories ..................................................................... 4
Top View ...................................................................................................... 6
Side View.................................................................................................... 10
Rear View ................................................................................................... 12
Bottom View ............................................................................................... 13
Measurement Screen ................................................................................... 14
Preparations.................................................................................................... 16
Backup Battery............................................................................................ 16
Power Supply .............................................................................................. 18
Tripod (option) Mounting ........................................................................... 21
Trigger Input ............................................................................................... 23
Using the Backlight .................................................................................... 23
Display Contrast ......................................................................................... 23
Setting the Date and Time .......................................................................... 24
Calibration .................................................................................................. 26
Using the Menu Screens ............................................................................. 30
Menu Screens.............................................................................................. 32
Factory Default Settings ............................................................................. 34
Setting Measurement Parameters.............................................................. 36
Sound Pressure Level Measurement......................................................... 42
Instantaneous Sound Pressure Level Measurement (LA, LC, Lp) ................ 43
Maximum and Minimum Sound Pressure Level Measurement
(Lmax, Lmin) ............................................................................................ 46
Waveform Peak Hold Measurement (Lpeak)................................................ 48
Equivalent Continuous Sound Pressure Level Measurement (Leq)............. 51
Sound Exposure Level Measurement (LAE)................................................ 53

vii
Takt-Max Sound Pressure Level Measurement (Ltm3, Ltm5) ....................... 54
Percentile Sound Pressure Level Measurement (Lx)................................... 57
1/1-Octave and 1/3-Octave Analysis ......................................................... 59
1/1-Octave and 1/3-Octave Analysis for Instantaneous Value
(LA, LC, Lp) ............................................................................................ 59
1/1-Octave and 1/3-Octave Analysis for Maximum and Minimum Level
(Lmax, Lmin) ........................................................................................... 60
1/1-Octave and 1/3-Octave Analysis for Equivalent Continuous
Sound Pressure Level (Leq) ................................................................... 61
1/1-Octave and 1/3-Octave Analysis for Percentile Sound Pressure Level
(Lx) ....................................................................................................... 62
Explanation of Analysis Screens ................................................................ 63
1/1-Octave and 1/3-Octave Analysis Precaution ........................................ 65
Data Exclusion (Back-Erase) Function.................................................... 66
Trigger Function............................................................................................ 68
Delayed Measurement .................................................................................. 74
Memory Functions......................................................................................... 76
Manual (Sound Pressure Level Mode) ....................................................... 78
Auto (Sound Pressure Level Mode) Single Store ....................................... 81
Auto (Sound Pressure Level Mode) Group Store ....................................... 84
Manual (Frequency Analysis Mode)........................................................... 87
Auto (Frequency Analysis Mode) Single Store .......................................... 89
Auto (Frequency Analysis Mode) Group Store .......................................... 93
Erasing Data ................................................................................................ 98
Recall Processing ........................................................................................ 99
Remote Control (NA-27RC1) ........................................................................ 101
Technical Notes ............................................................................................ 103
Microphone ............................................................................................... 103
Preamplifier .............................................................................................. 108
Preamplifier Specifications ....................................................................... 108

viii
Microphone Extension Cable (EC-04 series) ........................................... 109
Amplifier Circuit Configuration ............................................................... 112
Frequency Weighting Network ................................................................. 113
RMS Detection Circuit ............................................................................. 114
Measurement Functions ............................................................................ 117
Noise Floor ............................................................................................... 120
Background Noise..................................................................................... 121
Windscreen (WS-02) ................................................................................ 122
I/O Connector ........................................................................................... 125
1/1-Octave Filter Characteristics .............................................................. 126
1/3-Octave Filter Characteristics .............................................................. 127
Error Messages............................................................................................. 128
Optional Accessories................................................................................... 130
Microphone Extension Cables (EC-04 series) .......................................... 130
Level Recorder (LR-04, LR-06) ............................................................... 131
Using a Printer (DPU-414, CP-10, CP-11) ............................................... 134
Specifications................................................................................................ 140

1
Outline
The precision integrating sound level meter NA-27 allows digital 1/1-octave and 1/3-
octave analysis in real time. It conforms to legal requirements for quantity measurements
and to JIS and IEC standards. Using the output signal from a single microphone, the
NA-27 can determine values for different time constants and frequency weighting settings
simultaneously.
In addition to conventional noise level and sound pressure level measurements, the NA-27
can also determine the following quantities:
zEquivalent continuous sound pressure level Leq
zSound exposure level LE
zMaximum sound pressure level Lmax
zMinimum sound pressure level Lmin
zPercentile sound pressure level Lx
zTakt-max sound pressure level (3 or 5 s) Ltm3, Ltm5 *
zWaveform peak sound pressure level Lpeak
zPower average P_AVE
zPower sum P_SUM
zReverberation time REVERB
* Taktmaximalpegel Mittelwert: DIN
Power averaged maximum sound pressure level in a measuring period
Measurement data can be stored in the large-capacity internal memory of the NA-27.
These data can be sent to a computer, using the built-in serial port and a high-speed block
transfer protocol. In addition, an optical port allows data collection and data transfer under
computer control, and an infrared remote control unit is also supplied.

2
Outline
Processing functions in main channel and sub channel
*1 Lmax, Lmin, Leq, LE, Ltm3, Ltm5 are calculated simultaneously from Lpsampled at
10 ms intervals.
*2 Lxvalues are calculated simultaneously from Lpsampled at 100 ms intervals for
measurement times up to 1 h. For measurement times over 1 h, the sampling inter-
val increases by 100 ms for every hour.
*3 Set with the SETUP menu screen.
*4 Set with the DISPLAY menu screen.

3
Outline
Block diagram of NA-27

4
Controls and Functions
Carrying Case and Accessories
The unit is supplied with the parts listed below. Verify that all parts are complete and that
there is no damage. If any parts are missing or damaged, please contact the supplier.

5
Controls and Functions

6
Controls and Functions
Top View
Microphone/preamplifier
The microphone and preamplifier are configured as an integrated assembly. The micro-
phone and preamplifier are labeled with a serial number which must match the number
shown on the rear of the main unit. The microphone/preamplifier assembly can be
removed from the sound level meter and connected via an optional extension cable, for
measurements a distance.
Display
The backlit liquid crystal display has a resolution of 192 × 192 dots.
LED indicator
This indicator signals the following conditions.
Overload: Overload occurred in the main channel.
Measurement: Indicator flashes in 1 second intervals.
Remote control signal reception: Indicator flashes 3 times in 0.2 to 0.3 second inter-
vals.

7
Controls and Functions
Operation keys
START/STOP key
Press to start and to terminate the sound pressure level measurement (including the
various processing functions). The key is also used to store data in memory.
PAUSE/CONT key
Serves to temporarily pause and resume the measurement. When the data exclusion
(back-erasing) function is used, data for a certain number of seconds before the key was
pressed can be excluded from processing.
OPE MODE key
Serves to call up the various processing results on the display.
For the main channel, possible display items are instantaneous value (Lp), equivalent
continuous sound pressure level (Leq), sound exposure level (LE), maximum sound
pressure level (Lmax), minimum sound pressure level (Lmin), and percentile sound pres-
sure level (Lx). For the sub channel, the takt-max sound pressure level (Ltm3, Ltm5), and
the waveform peak hold level (Lpeak) can be displayed.
GRP/NUM/L-T key
In 1/1 octave and 1/3 octave mode, this key switches the display function between
graphical and numeric indication. When showing data stored in memory, the key can
be used to show the level-time indication.
SLM / 1/1 / 1/3 key
This key switches the operation mode between sound level meter (SLM), 1/1 octave
analysis (1/1), and 1/3 octave analysis (1/3).

8
Controls and Functions
CAL key
Pressing this key activates the built-in oscillator for electrical calibration of the NA-27
or for level matching of the NA-27 and connected equipment.
FREQ WEIGHT key
Selects the frequency weighting characteristic for the main channel. Available settings
are "A" weighting (A), "C" weighting (C), and flat frequency response (FLAT).
The frequency weighting characteristics for the sub channel are set with the SETUP
menu screen.
TIME CONST key
Selects the time weighting (time weighting) for the main channel. Available settings
are "FAST", "SLOW", "35 ms" and "10 ms". The time weighting for the sub channel is
set with the SETUP menu screen.
LEVEL UP LT key
Serves to select the level range. The level range cannot be set individually for the main
channel and sub channel. When showing the level-time display (from data stored in the
internal memory), the key serves to expand the time axis.
LEVEL DOWN LT key
Serves to select the level range. The level range cannot be set individually for the main
channel and sub channel. When showing the level-time display (from data stored in the
internal memory), the key serves to contract the time axis.
STORE key
Serves to start and stop the store process for entering data into the memory.
RECALL key
Switches the unit between the mode for recalling data from the memory (recall mode)
and the measurement data display mode (current mode).
INC, DEC keys
Serve to increase or decrease numerical values of the various menu entry items. When
data are being stored into the memory or displayed from memory, the keys serve to
select address numbers.
keys
Serve to select items from the menu screens.

9
Controls and Functions
keys
Serve to move the marker during frequency analysis. When a menu is displayed, the
keys serve to select parameters.
ENTER key
When a menu is displayed, the key serves to accept a setting.
PRINT key
Serves to start and stop printout of the current measurement screen or of data stored in
memory on a connected printer (DPU-414, CP-10, CP-11; option).
SETUP key
Pressing this key calls up the SETUP menu screen, for setting measurement param-
eters. Pressing the key once more returns to the measurement screen.
MEMORY key
Pressing this key calls up the MEMORY menu screen, for setting memory parameters.
Pressing the key once more returns to the measurement screen.
DISPLAY key
Pressing this key calls up the DISPLAY menu screen, for setting display parameters.
Pressing the key once more returns to the measurement screen.
I/O key
Pressing this key calls up the I/O menu screen, for setting input/output parameters.
Pressing the key once more returns to the measurement screen.
Optical port
This optical port allows sending measurement data over an infrared link to a computer
equipped with a suitable infrared port.
Remote control sensor
The signals from the remote control unit (NA-27RC1) are received here, allowing op-
eration of the unit from a distance of up to 3 meters.

10
Controls and Functions
Hand strap
The strap should be used to safely carry the unit during field work.
Side View