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 | MEWOI-TW408A(Class 1+1/1OCT) | MEWOI-TW408B(Class 1+1/1OCT+1/3OCT) | MEWOI-TW409A(Class 2+1/1OCT) | MEWOI-TW409B(Class 2+1/1OCT+1/3OCT) | 
| Accuracy | Class 1 | Class 1 | Class 2 | Class 2 | 
| Octave | 1/1OCT | 1/1OCT+1/3OCT | 1/1OCT | 1/1OCT+1/3OCT | 
| Real time 1/1 Octave: 8Hz-16kHz 
 Real time 1/3 Octave(Optional)6.3Hz 20 kHz GBT3241-2010 , IEC 61260-1:2014 ANSI S1.11-2004 . Base 10 system | Real time 1/1 Octave: 20Hz-8kHz 
 Real time 1/3 Octave(Optional) 20Hz-12.5kHz GBT3241-2010 , IEC 61260-1:2014 ANSI S1.11-2004 . Base 10 system | 
| Supplied Microphone | MPA231T: 1/2 pre polarized measurement microphone, Class 1. Sensitivity: 4 0mV/Pa. Frequency Range: 3 Hz~ 20kHz. | MPA309 T : 1/2 ” pre polarized measurement microphone, Class 2 . Sensitivity: 4 0mV/Pa. Frequency Range: 2 0Hz~ 12.5 kHz. | 
| Mic Interface | TNC connecter with ICCP power supply ( 4mA | 
| Detector / Filter | Fully float point digital signal processing (digital detector and filter | 
| Integral Period | Infinite or 1s 24h user define integra l period. Repeat time: I nfinite or 1~9999 | 
| Logger Step | 0.1s , 0.2s , 0.5s , 1s~24h | 
| Measurement Functions | LXY(SPL) SPL), L Xeq , L XY SD , L X SEL , L X E , L XYmax , L XYmin , L XPeak , L XN . Whe re X is the frequency weighting: A, B, C, Z; Y is time weighting: F, S, I; N is the statistical percentage 1 99 3 profile and 14 custom define measurement are calculat e in parallel with different frequency/time weighting | 
| 24h Measurement | Automatic measurement based on user define date/time and save 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 | 
| Self Noise | Sound: 19dB(A), 25dB(C),31dB(Z) Electrical:13dB(A), 17dB(C), 24dB(Z) | Sound:20dB(A), 26dB(C), 31dB(Z) Electrical:14 dB(A), 19 dB(C), 24dB(Z) | 
| Upper Limit | 136dB(A), Increase to 154dB(A) with 5mV/Pa Microphone | 
| Frequency Response | 10Hz~20kHz | 20Hz~12.5kHz | 
| Level Linearity Range | 22dB(A)-136dB A,Octave: 30dB-136dB | 25dB(A)~136dB(A),Octave: 33dB-136dB | 
| Dynamic Range | 123dB(13dB (A)~136dB(A)) | 122dB (14dB(A)~136dBA) | 
| Peak C Range | 47dB-139dB | 50dB~139dB | 
| Electrical I nput | Maximum input voltage: 5Vrms 7.07Vpeak ). Input impedance of preamplifier : >6 G Ω | 
| Range Setting | Single range to cover whole dynamic range | 
| Resolution | 24Bits | 
| Sampling Rate | 48kHz | 
| Time History | Time domain noise curve display. Duration time: 1min , 2min , 10min | 
| LCD Display | 160x160LCD with white backlight, 14 step contrast level , 1s display update rate | 
| Mass Storage | 4G MicroSD card ( TF card) | 
| Post Processing | Post processing software VA SLM ca n read , analy ze and generate reports of store data | 
| Export Data | Directly connect to the c omputer to read the memory card (USB disk) | 
| Output | AC Output max 5V RMS , 15mA ), DC Output (10mV/dB , max 15mA, RS232 serial interface and USB (USB disk mode or modem | 
| Alarm | User define alarm threshold. LED indicate the alarm status | 
| Setup Template | 5 templates to save user setup for different application, template can be save in MicroSD card | 
| Auto Power On | Automatic power on and start measurement when power supply available , ease of integration | 
| Power Supply | 4x1.5V alkaline batteries (LR6/AA/AM3), sustainable use of approx. 1 0 hours depend s on battery). It also can be supply by external DC power ( 14V 500mA) and USB po wer (5V 1A) | 
| RTC | Builtin backup battery has been calibr ated at factory to the error<26s in 30days (<10ppm, (25±16) ºC). It can keep RTC running when replacing the main batteries GPS timing function,available (optional with GPS) | 
| Language | English, Chinese,Portuguese , Spanish , German, French | 
| Firmware Update | Update firmware via USB port | 
| Conditions | Temperature: 10º C 5 0º C. Humidity : 20 9 0 %RH | 
| RT Temperature | Realtime tempera ture display on the main screen | 
| Size (mm) | W70 x H300 x D36 | 
| Weight | Approx. 620g , including 4 alkaline batteries | 
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 | Optional | 
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| GPS | 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 | 
| Calibrator | CA111, Class 1, 94dB/114dB, 1kHz | 
| Printer | Mini thermal or dot-matrix printer, RS232 port |