Ii is also indicated for certification according to the Leg. Decrees currently in force as regards environmental noise measurements and in working environments. These devices have a wide measuring range (from 25 to 140dB) and multiple functions such as statistic analysis, 24H analysis, integration of Leq over time, which are indispensable elements when measuring. These models also allows carrying out detailed analyses of spectrum components of noise using integrated octave-band filters and 1/3 octave-band filters (only HT157) and they are provided with an internal memory to save data and with a USB interface for transferring data to the PC through dedicated software in a Windows environment with possibility of numerical, graphic and statistic display. Sound level meters ape provided with a practical and resistant case with a mobile calibrator for preliminary checks before each measurement is carried out.
| Device category (Class) | Class 1 |
| Noise measuring range | 25 ÷ 140dB |
| Noise measurement resolution | 0.1 ÷ 0.01dB |
| Frequency range | 10kHz ÷ 20kHz |
| Dynamic range | 90dB |
| Measurement of sound pressure level (SPL) | |
| Measurement of equivalent noise levels (Leq) | |
| Frequency weighting | A/C/Z A/ |
| Integration over time | Fast/Slow/Impulse |
| Integration with programmable period | |
| Peak measurements (Peak-, Peak+) | |
| Display of MAX/MIN values of SPL | |
| Statistic analysis of noise with "A" weighting | |
| SPL analysis in 24H | |
| Spectrum analysis with octave-band filter (1/1) | 19Hz ÷ 16kHz |
| Spectrum analysis with 1/3 octave-band filter | |
| Provided mobile calibrator | Class 1 |
| Manual calibration with trimmer | |
| Precise calibration with internal procedure | |
| Pre-polarized “1/2” condenser microphone | |
| AC and DC analogue outputs with 3.5mm jack | Only AC |
| Internal memory for data saving | 128 |
| Recalling of results on the display | |
| Mini-USB interface for PC connection | |
| Windows software for saved data analysis | |
| Display | LCD 240 x 160 |
| Display backlight | |
| Power supply | |
| Provided external power supply | |
| Reference standards | IEC61672 Class 2 - IEC61620 Class 2 |
| Size (LxWxH) (mm) | 285 x 90 x 39 |
| Weight in grams (batteries included) | 500 |
