BSWA 308


NEW BSWA 308/NEW BSWA 309 are new generation digital sound level meter upgrade from base BSWA 308/309. The new types update the dual-core (DSP+ARM) architecture to single chip ARM with FPU, and update all fix-point calculation to float-point which significantly improves the accuracy and stability. Re-design analog front end circuit also lower the noise floor of sound level meter.

Single chip high speed ARM with FPU USB port function implemented
White backlight LCD Update firmware via USB (also power supply)
Integral period from 1s~24h Timer feature support auto measurement
0.1s, 0.2s, 0.5s logger step added Internal GPS (option) with GPS timing
5 templates to save user setting Single range to cover 123dB dynamic range
B-weighting added to meet ANSI standard Reduce the noise floor (only for Class 1)
Automatic power on with external supply, ease of integration Upper limit of measurement: 136dBrms/139dBpeak (40mV/Pa)

Product Features:

● Class 1 (NEW BSWA 308) and Class 2 (NEW BSWA 309) sound level meter

● Comply with IEC 61672-1:2013, ANSI S1.4-1983 and ANSI S1.43-1997

● 1/1 Octave in accordance with IEC61260-1:2014 and ANSI S1.11-2004

● Linearity range: 20dBA~134dBA (Class 1), 24dBA~136dBA (Class 2)

● Single range to cover 123dB dynamic range

● Frequency weighting A/B/C/Z. Time weighting Fast/Slow/Impulse

● 3profile calculation in parallel with different frequency/time weighting. 14 custom define measurement

● Calculate SPL, LEQ, Max, Min, Peak, SD, SEL, E

● LN statistics and time-domain curve display

● User define integral period measurement

● High speed ARM with FPU (Float Point Unit) to achieve wide dynamic range and low noise floor

● 4G MicroSD card (TF card) mass storage

● RS-232 remote control port

● Mini thermal printer for measurement data print

● Internal GPS module (option)

Technical Parameters:





Class 1 / Type 1


GB/T3785.1-2010, GB/T3785.2-2010, IEC60651:1979, IEC60804:2000, IEC61672-1:2013, ANSI S1.4-1983, ANSI S1.43-1997


Real-time 1/1 Octave: 8Hz~16kHz Optional Real-time 1/3 Octave: 6.3Hz~20kHz GB/T 3241-2010, IEC 61260-1:2014 ANSI S1.11-2004. Base 10 system

Supplied Microphone

MPA231T: 1/2” prepolarized measurement microphone, Class 1. Sensitivity: 50mV/Pa. Frequency Range: 6.3Hz~20kHz.

Mic Interface

TNC connecter with ICCP power supply (4mA/24V)

Detector / Filter

All float-point digital signal processing (digital detector and filter

Integral Period

1s-24h user define integral period. Repeat time: infinite, 1~9999

Measurement Functions

LXY(SPL), LXeq, LXYSD, LXSEL, LXE, LXYmax, LXYmin, LXPeak, LXN. Where X is the frequency weighting: A, B, C, Z; Y is time weighting: F, S, I; N is the statistical percentage: 1~99.

24h Measurement

Automatic measurement and log the history data

Frequency Weighting

Parallel A, B, C, Z (It can also be applied to 1/1 and 1/3 Octave)

Time Weighting

Parallel F, S, I and Peak detection


Sound: 18dB(A), 23dB(C), 31dB(Z) Electrical: 11dB(A), 16dB(C), 21dB(Z)

Upper Limit

134dB(A) Increase to 154dB(A) with 5mV/Pa Microphone

Frequency Response


Linearity Range


Dynamic Range

123dB (11dB(A)~134dB(A))

Peak C Range


Range Setting

Single range



Sampling Rate

48kHz(Sampling interval for LN: 20ms)

Noise Curve

Time domain noise curve display. Duration time: 1min, 2min, 10min

LCD Display

160x160 LCD with white backlight, 14 step contrast level

Mass Storage

4G MicroSD card (TF card)


Post-processing software VA-SLM can read, analyze and generate reports of store data

Export Data

Directly connect to the computer to read the memory card (USB disk)


AC (max 5VRMS output), DC (10mV/dB), RS-232 serial interface and USB virtual serial port


User define alarm threshold. LED indicate the alarm status

Power Supply

4x1.5V alkaline batteries (LR6/AA/AM3), sustainable use of more than 10 hours. It also can be supply by external DC power (7V-14V 500mA) and USB power (5V 1A)


Built-in backup battery has been calibrated at factory to the error <30s in 30days (<10ppm, 25?C). It can keep RTC running when replacing the main batteries. GPS timing function available (option with GPS module)

Firmware Update

Update firmware via USB port


Temperature: -10℃~ 50℃. Humidity: 20% ~ 90%RH

RT Temperature

Real-time temperature display on the main screen

Size (mm)

W70 x H300 x D36


Approx. 620g, including 4 alkaline batteries


Receiver Type: 50 Channels; Time-To-First-Fix: Cold Start 27s, Warm Start 27s, Hot Start 1s; Sensitivity: Tracking -161dBm, Reacquisition -160dBm, Cold Start -147dBm, Hot Start -156dBm; Horizontal position accuracy: 2.5m, Timing accuracy: 30ns, Velocity accuracy: 0.1m/s; Update Rate: 1Hz, Operation Limits: Dynamic≤4g, Altitude<50000m, Velocity<500m/s


CA111, Class 1, 94dB/114dB, 1kHz


Mini-needle or thermal printer, optional, RS-232 port


firmware software



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