
SR6661
Sound Level Meter Class 1
Features:
Complies
with IEC61672 Class 1
Accurate testing results
RS232 interface output are available
Impulse sound level
Latest digital signal processing technology
Wide dynamic range
High precision
Modular design, on demand selection
Wide warm design, operating temperature from 15ºC to 50ºC
Applications:
Widely
use in industrial noise surveys, machinery, vehicles, ships and etc
May also be used in ambient noise



Model 
SR66611 
SR66611A 
SR66611B 
SR66611C 
SR66612 
SR66613 
Specialty 
Precision pulse 
Wide bandwidth 
Low noise measurement 
High noise measurement 
Precision integral 
Super
function 
Sensitivity 
30dB 
28dB 
25dB 
53dB 
30dB 
Frequency Weighting 
A, C, Z 
Time Weighting 
F, S, I, Peak 
Frequency
Range 
10Hz~16kHz 
10Hz~20kHz 
10Hz~16kHz 
10Hz~20kHz 
10Hz~16 kHz 
Meas. Upper Range 
>140dB 
>138dB 
>135dB 
>160dB 
>140dB 
Self generated Noise 
<20dBA 
<18dBA 
<10dBA 
<40dBA 
<20dBA 
Display 
128mm*64mm LED 
Output 
AC, DC, RS232 
Sampling Frequency 
48kHz 
Integrating Function 
No 
No 
No 
No 
Yes 
Yes 
Integrating
Time 
No 
Manual,10s, 1m, 5m, 10m, 20m, 30m, 1h, 2h,
4h,
8h, 12h, 16h, 24h 
1s~24h 
Main
Parameters of Meas. 
Lp, Lmax, Lpeak 
Lp,
Lpeak, Lmax, Lmin, SEL, E 
LXYp, LXeq, T, LXYmax, LXYmin, LN (Note: X
is A, C, Z; Y is F, S, I; N can be 199)SEL, Lex, 8h, Lavg,
TWA, DOSE, E, SD, LXpeak 
Statistical Analysis
Function 
No 
Optional 
Yes 
Over Limit Indication 
Yes, limits can be settled 
Data Storage 
No 
8000 Groups 
Recording Function 
No 
Optional 
Working Temp. 
15°C~50°C 




SR6691 Real Time Sound Signal
Analyzer
Class 1
Features:
Frequency Range: 10Hz~20KHz
Complies with IEC61672 class 1 and IEC61260 class 1
CE certificate
Pockettype realtime noise signal analyzer
FFT analysis on noise or vibration
90dB level linearity range
Different software could be selected
Autostart and autoend
Applications:
Precision acoustics measurements
Realtime frequency analysis in 1/1 and 1/3 octave digital filters
Environmental noise measurement and 24 hour monitoring
Reverberation time measurements
Airport Noise Monitoring and data collect 


Model 
SR66911 
SR66912 
SR66913 
SR66914 
SR66915 
SR66916 
SR66917 
SR66918 
Fulfils Standards 
IEC61672 class 1 and IEC61260 class 1 
Microphone 
1/2"Prepolarized Condenser
Mic.(sensitivity: 50 mV/Pa) 
Frequency Range 
10Hz~20kHz 
Range Gain 
10dB, 0dB, 10dB, 20dB, 30dB, 40dB, Range
Error: ≤0.1 dB. 
Selfgenerated Noise 
<18 dB(A), 23 dB(C), 28 dB(Z) 
Meas. upper Range 
140dB 
Peak C Sound Level Measuring Range 
50~143dB 
Frequency Weighting 
Parallel (simultaneous) A, C, Z.
Realized
by digital filtering 
Time Weighting 
Parallel F, S, I, Peak C^{+},
Peak C^{} 
A/D Bits 
24 bits 
Level Linearity Range 
>90 dB 
Sampling Frequency 
48 kHz 
Display 
240*160mm graphic LCD, with EL backlit 
Display Refresh 
1 Hz for value; 10 Hz for graph 
Main Parameters of Integrating
Measurement 
L_{xyp}, L_{xyi}, L_{xeq,1s},
L_{xeq,T}, L_{AE}, E, C_{peak+},
C_{peak}, L_{AFmax}, L_{AFmin},
L_{AFeqT}, L_{ASeqT}, L_{AIeqT,
Note: X is A, C, Z and Y is F, S, I} 
Main Parameters of Airport Noise Meas. 
L_{EPN}, T_{d}, L_{max} 
Display Resolution 
0.1dB 
Realtime spectrum analysis 
Fulfils
standards: IEC61260 Class 1
Filter type: Digital bandpass filter
Meas. Parameters: Lfmi, Lfmeq, 1s, Lfmeq, T, Lxyp, Lxyi,
Lxeq, 1s, Lxeq, T, LAE, E, Cpeak, Tm
Note: fm is center frequency; X is frequency weighting
A, C, Z. Y is time weighting F, S, I

Realtime Analysis Speed 
Approx. 47 times/s (It can simultaneously
complete all center frequencies and A, C, Z weighting) 
Statistical analysis Function
Statistical analysis software
Statistical analysis Menu: LAFp, LAFmax, LAF5, LAF10,
LAF50, LAF90, LAF95, LAFmin, SD, LAeq1 s, LAeq, T, LAE,
LAFeqT.
24 hours monitors menu: And Ld, Ln, Ldn 
Yes 
No 
Yes 
No 
Yes 
Yes 
Yes 
No 
Realtime 1/1 OCT spectrum analysis
1/1 OCT spectrum analysis software for
noise
Filters Center Frequency: 16 Hz~16 kHz 
No 
Yes 
Yes 
No 
No 
Yes 
Yes 
Yes 
Realtime 1/3 OCT spectrum analysis
1/3 OCT
spectrum analysis software for noise
Filters Center Frequency: 10 Hz~20 kHz 
No 
No 
No 
Yes 
Yes 
Yes 
Yes 
Yes 
FFT
analysis function,
FFT
analysis software for noise
Line Number: 200 lines on the display
Sampling Frequency: 48 kHz, 24 kHz, 12 kHz,6 kHz, 3 kHz,
1.5 kHz.
Upper Limit of Analysis Frequency: 18.75 kHz, 9375 Hz,
4687 Hz, 2344 Hz, 1172 Hz, 586 Hz
Bandwidth of each line: 93.75 Hz, 46.875 Hz, 23.438 Hz,
11.74 Hz, 5.8594 Hz, 2.9297 Hz
Average Method: index and linearity
Measuring Parameters: Lxyp, Lxyi, Lxeq,1s, Lxeq,T, LAE,
E, Cpeak,Tm in every line 
No 
No 
No 
No 
No 
No 
Yes 
No 
Reverberation time measurement function
Reverberation time measurement software
Function: Reverberation time, EDT measurement by
integrated impulse response method.
Fulfils Standard: ISO 3382
Measuring Parameters: T20, T30, EDT
Measuring Range: 0.20s to 20.00 s
Wave record time: 10 s or 20 s
Bandwidth of digital filters:1/1 OCT or 1/3 OCT
Center Frequency Ranges: 63 Hz ~ 16 kHz for Oct, 40 Hz ~
16 kHz for 1/3 Oct
Date store: Max 12288 groups reverberation time, also
translate to U disc 
No 
No 
No 
No 
No 
No 
No 
Yes 
Data Storage 
64M bits Flash, instantaneous data, 1
second integral results and integral measuring result
(maximum 12288 groups). Also can be stored in Flash disk
or transferred to the Flash disk through USB interface 
Integral Time 
Manual, 10s, 1min, 5min, 10min, 15min,
20min, 30min, 1h, 4h, 8h, 24h or 1min~59 min 
Print 
Can print analytical results in the
miniprinter, can also print the contents showed on LCD,
miniprinter 40S is optional 
Data Recall 
Recalled any data 
Intelligent Delete 
Burst event may be deleted scientifically 
Internal Clock 
Error less than 1 min/month 
Output Interface 
Stereo Connector AC Signal Output
RS 232 interface to the miniprinter, or connected to PC
USB Interface, which can transfer the measuring results
to PC, or the Flash disk 
Power Supply 
6×LR6 alkaline battery or rechargeable
batteries, which can work for over 12 hours
continuously. 9 V external power supply is also
acceptable 
Dimensions 
310(H)*90(W)*38(D)mm 
Weight 
0.5kg (include batteries) 
EMC 
Type X 
Working Temperature 
10°C~50°C 
Relative Humidity 
25~90% 
Atmospheric Pressure 
65kPa~108kPa 




SR6228+ Color screen Sound Level Analyzer
Class 1
Features:
 A handhold noise measuring instrument
 Multifunction and user friendly sound level meter (sound level meter,
integrating SLM, 1/1 OCT, 1/3 OCT analyzer, FFT analyzer, Noise dosimeter)
 240×320 color screen
 Measurement range up to 142dB
 Synchronously do integrating measure, statistical, realtime 1/1 OCT, 1/3 OCT,
FFT analysis and noise dosimeter measure
 Comply with IEC 61672 Class 1 and IEC61260 Class 1 and IEC 61252
Applications:
 Comprehensive noise measurements
 Environment noise certification
 Noise profile measurement of industrial noise
 Peak C sound level measurements
 Impulse noise measurements
 Workplace noise assessments
 Industry boundary assessments 
Specifications:
Fulfils Standards 
IEC 61672 Class 1, IEC 61260 Class 1, IEC61252:2002, IEC
60651:2001 Type 1, IEC 60804: 2000 Type 1, ANSI S1.4: 1983
Type 1,
ANSI S1.4A:1985 Type 1, ANSI S1.43:1997 Type 1, ANSI
S1.25:1991 
Microphone+ preamplfier 
1/2” prepolarized condenser microphone+ Preamplifier
(Sensitivity Level: 28dB) 
Preamplifier 
AWA14601 removable preamplifier 
Frequency Range 
10 Hz ~ 20 kHz ± 1 dB (not including microphone) 
Total Measurement Range 
Low range: (20～132)dBA,
(25132)dBC, (30132)dBZ
High range: (30～142)dBA,
(35142)dBC, (40142)dBZ 
Selfgenerated Noise 
<12 dB(A), 17 dB(C), 22 dB(Z) 
Frequency Weighting. 
Parallel (simultaneous) A, C, Z, B, D and user1&2defined
weighting 
Time Weighting 
Parallel (simultaneous) F, S, I, Peak 
Measurement Parameters 
Lxyp, Lxyi, Lxeq,1s, Lxeq,T, LAE, E, Cpeak, LAFmax, LAfmin,
LAfeqT, LAseqT, LAieqT.
Note: X is A, C, Z and Y is F, S, I 
A/D Bits: 
24 bits 
Sampling Frequency 
48 kHz 
Calibration 
Using Sound Calibrator Class 1 model AWA6221A 
Correction Function 
Press field correction in order to comply with standards
ANSI S1.4 
Delay Time 
The meter can delay 0~99s after pressing start measuring
button 
Back Erase Function 
Elimination of undesired noise; example barking dogs, cars,
doors 
Display 
240×320 color screen, adjustable brightness, backlight can
be closed 
Display Resolution 
0.1 dB 
Low battery indication 
Symbol indicate low battery 
Data Storage
(32 Mb FLASH RAM.
SD memory card is optional) 
* 3328 groups of
integrating measuring results only.
* 3328 groups of
statistical results only (‘statistical 1’ and ‘statistical
2’ analysis index are same.)
* 2663 groups of
statistical results only (‘statistical 1’ and ‘statistical
2’ analysis index are different.) 
Print
(Optional) 
Miniprinter 
Internal Clock 
Error less than 1 min/month 
Output Interface 
AC Output (full scale): 1.0V AC RMS; Output Impedance: 1k Ω;
Connector: φ3.5 mm stereo plug 
DC Output: 20mV/dB; Output Impedance: 1k Ω; Connector: DB9
plug 
RS232 Interface: To computer for output some measurement
results instantaneous values , also to miniprinter for
printing
Transmission speed: 4800, 9600,115200 bps 
USB Interface: available and no need device drive.
Allow USB to be controlled via communication commands 
Power Supply 
4×LR6 alkaline battery or rechargeable batteries 
5 V external power supply 
Battery Life 
Longest time of 30 hours continuously with 4×LR6 alkaline
battery 
Dimensions 
260 (H) x 80 (W) x 30 (D), mm. 
Weight 
0.35 kg. (include batteries) 
EMC 
Type X 
Environment: 
Working Temperature: 10 ~ 50 °C
Storing Temperature: 20 ~ 70 °C
Relative Humidity: 25 ~ 90 % 
Accessories 
AC adaptor, USB cable, RS232 transmission cable, windscreen,
hand strap, windscreen fall prevention rubber, carrying
case, Udisk, user’s manual 
Bluetooth Module (Optional) 
Can communicate with smart phone and realize wireless
control sound level meter 
Function of optional Embedded
Software and Hardware :
Type & Name 
Main function 
SR6228+ host (standard
configuration) 
Host hardware part (Don’t include transducer and software),
box, transfer software. 
SR6228+ 10100 Integral software 
The noise integral measuring 
SR6228+ 10101 Statistics analytical software 
The statistical analysis, 24 hours noise monitors
automatically. 
SR6228+ 10202 The OCT analysis software 
Noise realtime OCT spectral analysis 
SR6228+ 10303 The 1/3OCT analysis software 
Noise realtime 1/3OCT spectral analysis 
SR6228+ 10404 The FFT analysis software 
Noise realtime FFT spectral analysis 
SR6228+ 00013 The Noise Dosimeter software 
Noise dosimeter measuring 
SR6228+ 00509 The Data Logging software 
Do data logging 
SR6228+ 00508 The Reverberation Time Measurement software 
Reverberation Time Measurement 
Model SR4601 Preamplifier 
Preamplify, gain is 0 dB. 
Model SR4423 measuring microphone 
1/2", Prepolarized condenser microphone, 10 Hz ~ 20 kHz, 50
mV/Pa. 
Windscreen S80 
Reduce the affection of wind 
AH40 Miniprinter 
Print measuring result, include connecting line, print paper 
Extension cable with 5, 10 or 20 m 
For SR4601 and SR6228+ host 
32G SD memory card& recording 
GPS positioning modular 
Bluetooth function 
Tripod (1.46m Height) 



Sound Level Calibrator 



SR30X
Sound level calibrator
Introduction
SR30X Sound level calibrator can be used in the absolute pressure calibration of
sensor, sound level meter and other acoustics measuring meters. The unit is
designed as a compressible sound pressure and good stability. With the battery
to supply power, it’s very convenient for use.
Technical Specifications
Material 
ABS engineering plastic
housing, safe and reliable 
Output sound level

114dB and 94dB under 20upa

Accuracy 
±0.5dB 
Output frequency

1000Hz±2% 
Harmonic Distortion

＜3% 
Reference condition 
Temperature: 23°C

RH:
50% 
Atmosphere pressure:
1013mbar 
Power and low battery
indicator 
1/2 inch diameter microphone
accommodated 
Power supply 
9V block battery (6F22/
6LR61) 
Working current 
<20mA 
Operating temperature

0°C~45°C

Working humidity

5%~95%RH noncondensing

Storage Condition

20°C~+60°C,
≤85% (without
battery) 
Dimension 
108*56*34mm

Weight 
About 62g (w/o Battery) 




SR29A, SR29B Sound Level Calibrator
Specification 
Model 
SR29
Sound Level Meter Calibrator 
Model
suffix 
SR29A 
SR29B 
Standard 
GB/T15173, ANSI S1.40 CLASS2, IEC942 
Output
sound level 
94dB 
94dB 
114dB 
114dB 
Accuracy 
0.5dB 
0.3dB 
Frequency 
1000Hz 
Design
for 
1",
1/2" 
Power
supply 
1x9V
6F22 Battery 
Dimension 
142x47x47mm 
Weight
(Not including battery) 
275g 
Standard Accessories 
Main
Unit 
1 
Carry
Case 
1 
Operation Manual 
1 



Features:
Pocket size, portable unit
Comply with IEC60942 Class 1
CE Certification, 94dB and 114dB Sound Calibration at 1KHz 
SR21A
Sound Level Calibrator Class 1
Specifications:
Fulfils Standards 
IEC60942
Class 1 
Normal
sound pressure level 
94dB, 114dB 
Sound level
accuracy 
±0.2dB(+23°c), ±0.3dB(10°c~+50°c) 
Normal
frequency 
1000 Hz 
Frequency
accuracy 
±1% 
Distortion
(THD) 
<1% 
Power
supply 
1*6F22(9V)
battery, operating current: 10mA 
Battery
check 
As long as
the signal continues for one minute after the contact is release,
otherwise battery low 
Reference
conditions 
Ambient
temperature: 23°C;
Ambient Pressure: 1013hPa;
Ambient Humidity: 65% 
Working
conditions 
Temperature: 10°C~+50°C;
Humidity: 25%~90%(RH),
Atmospheric Pressure: 650hPa~1080hPa 
Dimensions 
φ52*116mm 
Weight 
<450g(include battery) 
Microphone
Type 
1" and
1/2"(with supplied adaptor) 
Accessories: 
Battery
6F22*1,
Instruction Manual*1,
Adaptor for 1/2" microphone*1,
Leather case*1 



Features:
Comply with IEC60942 Class 2
94dB Sound Calibration at 1KHz 
SR21B
Sound Level Calibrator
Specifications:
Fulfils Standards 
IEC60942
Class 2 
Normal
sound pressure level 
94dB 
Sound level
accuracy 
±0.3dB(+23°c), ±0.5dB(10°c~+50°c) 
Normal
frequency 
1000 Hz 
Frequency
accuracy 
±2% 
Distortion
(THD) 
<1.5% 
Power
supply 
1*6F22(9V)
battery, operating current: 10mA 
Battery
check 
As long as
the signal continues for one minute after the contact is release,
otherwise battery low 
Working
conditions 
Temperature: 10°C~+50°C;
Humidity: 25%~90%(RH),
Atmospheric Pressure: 650hPa~1080hPa 
Dimensions 
φ40*100mm 
Weight 
<250g(include battery) 
Microphone
Type 
1" and
1/2"(with supplied adaptor) 
Accessories: 
Battery
6F22*1,
Instruction Manual*1,
Adaptor for 1/2" microphone*1,
Leather case*1 



Measure Microphone 

Features:
Comply with IEC 61672 Class 1 or 2;
Low ambient temperature coefficient;
High resistance to humidity.
Uses:
Precision acoustic measurements;
Pressure variation measurements.
Specifications:
Model 
Diameter 
Open Circuit Sensitivity (mV/Pa) 
Polarization Voltage (V) 
Frequency Range (Hz) 
Frequency Response Characteristic 
Dynamic Range (dB) 
Capacitance (pF) 
Ambient Temperature
Coefficient (dB/°C) 
Dimensions 
SR4403 
Φ12.7mm (1/2”) 
15 
200 
20~40,000 
Free filed 
30~160 
18 
0.01 
Type WS1 
SR4404 
15 
20~12,000 
Pressure filed 
30~160 
18 
0.01 
Type WS1 
SR4422 
30 
0 
20~10,000 
Pressure filed 
20~142 
15 
0.02 
Type WS2 
SR4423 
50 
10~20,000 
Free filed 
16~140 
19 
0.01 
Type WS2 
SR4425 
40 
10~16,000 
Free filed 
17~140 
20 
0.01 
Type WS2 
SR4431 
Φ6.35mm (1/4”) 
4 
10~70,000 
Free filed 
40~160 
6 
0.01 
Type WS3 
SR4435 
4 
10~20,000 
Free filed 
40~160 
6 
0.01 
Type WS3 


Microphone Preamplifier 





SR4601 
SR4603 
SR4604 
SR4614E 
SR4600E 
Features:
1/2" prepolarized microphone
compatible;
Lemo connector with cable for easy
installation and use;
Low output impedance so that long
extension cable can be used.
Uses:
Signal analysis measurements setups;
With 1/2" Prepolarized Condenser
Microphones;
Sound power measurements;
Machinery noise measurements.
Specifications:
Models 
SR4601 
SR4603 
SR4604 
SR4614E 
SR4600E 
Photos 





Frequency Response
(re. 250 Hz) 
10Hz~20kHz, +0.2dB
5Hz~200kHz, +0.5dB 
10Hz~50kHz, +0.2dB
5Hz~50kHz, +0.5dB 
20Hz~20kHz, +0.2dB
10Hz~100kHz, +0.5dB 
20Hz~20kHz, +0.2dB
10Hz~100kHz, +0.5dB 
10Hz~20kHz, +0.2dB
5Hz~200kHz, +0.5dB 
Measurement Range
(dB) (re. 50mV/Pa) 
15~140 
15~120 
15~134 
15~134 
15~140 
Gain 
0.2dB 
20dB 
0.15dB 
0.25dB 
0.2dB 
Input Impedance 
≥10GΩ//0.5pF 
≥10GΩ//0.35pF 
≥10GΩ//0.35pF 
≥10GΩ//0.35pF 
≥10GΩ//0.5pF 
Noise 
Aweighting (20pF) <2.5u
Zweighting
(20pF) <10uV 
Aweighting (20pF) <4uV
Zweighting (20pF) <10uV 
Aweighting (20pF) <4uV
Zweighting (20pF) <15uV 
Aweighting (6.5pF) <8.5uV
Zweighting (6.5pF)
<35uV 
Aweighting (20pF) <4uV
Zweighting (20pF) <10uV 
Distortion (THD) 
<60dB 
Output Impedance 
<150Ω 
<50Ω 
<50Ω 
<50Ω 
<150Ω 
Max. Output Voltage 
20Vpp (at power voltage 30V) 
8VRMS (at power voltage 30V) 
6VRMS (at power voltage 24V) 
6VRMS (at power voltage 24V) 
20Vpp (at power voltage 30V) 
Power Voltage 
15~45V 
9~30V 
1CP 2mA~10mA 
1CP 2mA~10mA 
15~45V 
Operating Current 
1mA 
2mA 
1CP 2mA~10mA 
1CP 2mA~10mA 
1mA 
Polarization Voltage (V) 
200, 28, 0 
0 
Outside Diameter 
Φ12.7mm (1/2”) 
Φ6.35mm (1/4”) 
Φ12.7mm (1/2”) 
Weight 
<20g (not include cabel) 
