SOUND LEVEL METER The testo 816-1 is ideal for sound level measurements at workplaces, in industrial and production halls, and in public places. With the touch of a button, the measuring instru-ment can be switched from Slow (1 sec.) to Fast (125 ms). It is also possible to switch between the frequency weighting characteristic curves A and C and vice versa, also at the touch of a button. Characteristic curve A corresponds to the sound pressure sensitivity of the human ear, while characte-ristic curve C can evaluate low-frequency components of a noise. Integrated Data Storage: The integrated data store allows the storage of over 30000 measurement values in the instrument, these can be administered using the software included in delivery. In addition to this, the software allows online measurements over a longer period to be carried out. With the optional sound calibrator and the adjustment ac-cessory included with it, the testo 816-1 can be recalibrated on site. Sound level measurement acc. to IEC 61672-1 class 2 and ANSI S1.4 Type 2 Frequency weighting A and C Integrated data storage for up to 31000 measurement values Software for data management and long-term measurement Switchable time weighting Fast/Slow Bar graph display Backlit display AC and DC output for the connection of other intruments   816-1 Sound Level Meter Technical data: Accuracy ±1 digit    ±1.4 dB (under reference conditions: 94 dB, 1 kHz) Measuring range    30 to 130 dB Frequency range    20 Hz to 8 kHz Resolution    0.1 dB Frequency weighting    A / C Microphone    ½ inch Measuring rate    0.5 s Dynamic range    100 dB Data storage    approx. 31000 measurements Operating temperature    0 to +40 °C Storage temperature    -10 to +60 °C Battery type    4 x Type AA batteries Weight    390 g Dimensions    272 x 83 x 42 mm Time weighting    FAST 125 ms / SLOW 1 sec AC/DC output    AC: 1 V RMS at full scale / DC: 10 mV/dB