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RION Sound Level Meter NL-52( Class 1)・NL-42( Class 2)

Extremely User Friendly! Provide full support for the measurement process!

The NL-52 and NL-42 were developed to eliminate the trouble of reading instruction manuals when conduction measurements.
Large and easily viewable three-inch LCD color display.
The unit (except for the microphone) is water-resistant, which means that it is unaffected by sudden rain showers.
You can use rechargeable batteries to help cut down on waste, making this an environmentally friendly product.

Sound Level Meter


NL-52( Class 1)/NL-42( Class 2)




  • No paper manual is needed
  • Water-resistant (Except for the microphone)
  • Use of rechargeable batteries
  • Continuous detailed measurements for one month
  • Functionality can be extended by a range of options

NL-42/52/62: Sound Level Meter



NL-52 NL-42
Applicable standards IEC 61672-1: 2013/2002 class 1
ANSI/ASA S1.4-2014/Part1 class 1
JIS C 1509-1: 2017 class 1
IEC 61672-1: 2013/2002 class 2
ANSI/ASA S1.4-2014/Part2 class 2
JIS C 1509-1: 2017 class 2
CE marking
WEEE Directives, Chinese RoHS (export model for China only)
Measurement functions Simultaneous measurement of the following items, with selected time weighting and frequency weighting
Processing (main ch) Instantaneous sound pressure level: Lp
Equivalent continuous sound pressure level: Leq
Sound exposure level: LE
Maximum sound pressure level: Lmax
Minimum sound pressure level:
Percentile sound levels: LN (0.1 to 99.9 %, 0.1-increment steps, max. 5 values)
Processing (sub ch) Instantaneous sound pressure level: Lp
Additional processing In addition to main processing items, one of the following can be selected for simultaneous processing:
C-weighted equivalent continuous sound level: Lceq
C-weighted peak sound level: Lcpeak
Z-weighted peak sound level: Lzpeakエ-time-weighted equivalent continuous sound level: LAエeq*2
Maximum エ-time-weighted equivalent continuous sound level: LAエmax*2
The power average of the maximum level of each 5 second interval: LAtm5
The frequency weighting for the additional processing synchronizes with the frequency weighting of the sub-channel, so when the sub-channel has A-weighting, LAtm5 can be selected.
When C-weighting (Z-weighting ) is selected, the additional processing LCeq and LCpeak (LZpeak) are selectable.
Microphone Type UC-59 UC-52
Sensitivity level -27 dB -33 dB
Measurement range A-weighting: 25 dB to 138 dB
C-weighting: 33 dB to 138 dB
Z-weighting: 38 dB to 138 dB
C-weighting peak sound level: 55 dB to 141 dB
Z-weighting peak sound level: 60 dB to 141 dB
Inherent noise A-weighting 17 dB or less 19 dB or less
C-weighting 25 dB or less 27 dB or less
Z-weighting 30 dB or less 32 dB or less
Frequency range 10 Hz to 20 kHz 20 Hz to 8 kHz
Frequency weighting A, C, and Z
Time weighting F (Fast) and S (Slow)
Level range Single range (Linearity range: 113 dB)
Bar graph display range max Max. 110 dB (20 to 130 dB)
Switching of bar graph display Set the upper/ lower limit in 10 dB increments.
RMS detection circuit Digital processing method
Sampling cycle 20.8 μs (Lp, Leq, LE, Lmax, Lmin, Lpeak : sampling frequency: 48 kHz) 100 ms (LN )
Calibration Electrical calibration performed according to IEC and JIS standards, using internally generated signals: acoustic calibration performed with the NC-75.
Correction functions Windscreen correction:
Compliant with IEC 61672-1 and JIS C 1509-1 standards when the windscreen is installed.
Diffuse sound field correction:
Correction of frequency characteristics in order to comply with standards (ANSI S1.4) in diffuse sound field.
Delay time The meter can be set to start measuring a specified time (OFF, 1, 3, 5 or 10 s)
after the start button has been pressed or when a user-set trigger is exceeded.
Back erase function When the PAUSE key is pressed to pause measurement, the preceding
(user selectable) 0, 1, 3 or 5 s data are excluded from processing.
Display Backlit semitransparent color TFT LCD display WQVGA (400 x 240 dots)
*LCD with touch panel (Capacitive Touch Panel)
Numerical display update frequency: 1 s   Bar graph update frequency: 100 ms
Store Manual Data for measurement results are stored manually in single address increments.
Number of data Internal memory: max. 1 000 sets
SD Card: depends on the capacity of the SD Card*1
Auto*2 Instantaneous values (Lp mode) and processed values (Leq mode) are stored continuously and automatically at preset intervals.
Lp sampling cycle 100 ms, 200 ms, 1 s, Leq 1s
Leq sampling cycle 10 s, 1, 5, 10, 15, 30 min, 1, 8, 24 h, and user selected time (up to 24 hours)
Measurement Time Max. 1 000 h in Auto Lp storage mode, max. 100 000 addresses in Auto Leq storage mode(depends on the capacity of the SD card)*1
Data recall Allows viewing of stored data
Setup memory Up to five setup configurations can be saved in internal memory, for later recall
Start up via file settings previously stored on SD card possible
Waveform recording*2*3 File format Uncompressed waveform WAVE file
Sampling frequency Select 48 kHz, 24 kHz or 12 kHz
Data length Select 24 bit or 16 bit
Outputs DC output Output DC signals using a frequency weighting characteristic selected by processing.
Output voltage 2.5 V, 25 mV / dB at bar graph display full scale
AC output Output AC signals using a frequency weighting characteristic selected by processing or by A, C, Z-weighting.
Output voltage 1 V (rms values) at bar graph display full scale
Comparator output*2 Turns on when the open-collector output exceeds the set value
(max. applied voltage 24 V, max. current 60 mA, allowable dissipation 300 mW).
USB Allows USB to be connected to a computer and recognized as a removable disk
Allows USB to be controlled via communication commands
RS-232C communication Allows for RS-232C communication via use of a dedicated cable
Data continuous output*2 Type of data Instantaneous value Lp
Processed value Leq, Lmax, Lmin, Lpeak
Output interval 100 ms
Power requirements Four IEC R6 (size AA) batteries (alkaline or rechargeable batteries) or external power supply
Battery life (23 ˚C) Alkaline battery LR6 (AA): 26 h Ni-MH secondary battery: 25 h
At the maximum *Depends on the setting
AC adapter NC-98E
External power voltage 5 to 7 V (rated voltage: 6 V)
Current consumption Approximately 90 mA (normal operation, rated voltage)
Ambient conditions Temperature -10 to +50 ˚C
Humidity 10 to 90 % RH (non-condensing)
Dustproof / water-resistant performance*4 IP code: IP54 (except for microphone)
See precautions regarding waterproofing
Dimensions, weight Approx. 250 (H) x 76 (W) x 33 mm(D), approx. 400 g (with batteries)
Supplied accessories Storage case x 1, Windscreen WS-10 x 1, Windscreen fall prevention rubber x 1,
Hand strap x 1, LR6 (AA) alkaline batteries x 4, SD card 512 MB×1 (NX-42EX preinstalled model only)

*1 Use Rion fully guaranteed products. *2 NX-42EX required (sold separately).

*3 NX-42WR required (sold separately).
*4 Protection against harmful dust and water splashing from any direction.
Precautions regarding waterproofing
Before use, verify that the rubber bottom cover and the battery compartment lid are firmly closed.
To maintain the water and dust proof rating, internal packing replacement is required every two years (at cost).

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