SAUTER SW 1000 Class 1 sound level metre, data logger, octave band filter

Wave mechanics and acoustic metrology of accuracy class 1

In occupational health and safety, comprehensive environmental monitoring and building acoustics analysis, the physically accurate measurement of sound pressure levels is a highly critical metrological requirement. The SAUTER SW 1000 is designed as a precise reference instrument of accuracy class 1 (in accordance with IEC 61672-1). The device measures the longitudinal pressure waves of sound across an extremely wide dynamic measurement range. To represent the enormous differences in sound pressure – from the absolute hearing threshold right up to the pain threshold in industrial mechanical engineering – linearly and without logarithmic distortion, the measuring system is equipped with a highly sensitive, capacitive 1/2-inch free-field microphone. The ultra-thin diaphragm converts the mechanical kinetic energy of the sound waves into electrical voltage fluctuations without any delay; these are then processed by the internal electronics at the highest sampling rate.

Digital Signal Processing (DSP) and Frequency Weighting

The objective physical measurement of sound pressure differs fundamentally from the subjective psychoacoustic perception of the human ear. The SW 1000’s internal microprocessor utilises advanced digital signal processing (DSP) to physically filter the incoming raw signal in real time. The device supports the standardised frequency weightings A, C and Z (linear). Whilst the A-weighting simulates the frequency-dependent sensitivity of the human ear, the unweighted Z setting is essential for the physically accurate quantification of low-frequency infrasound emissions from industrial plant. In parallel, the selectable time weighting (Fast, Slow, Impulse) enables precise analysis of signal dynamics – from continuous background noise through to explosive, transient sound events (impulse noise). An outstanding analytical feature is the integrated octave-band filter, which breaks down the complex frequency spectrum into discrete physical bands, thereby enabling the precise identification of resonance frequencies or disruptive tonal characteristics in machinery.

Hardware integrity and GLP-compliant data logging

To ensure the integrity of the raw acoustic data during long-term measurements under adverse microclimatic conditions, the SW 1000 is designed as a self-contained measurement system. The sensitive microphone capsule can be detached for interference-free calibration (using an external acoustic calibrator) or operated remotely via an extension cable for measurements in hard-to-access machine rooms. The supplied windscreen effectively eliminates aerodynamic noise caused by air turbulence. For certified test laboratories subject to strict GLP (Good Laboratory Practice) or ISO regulations, the instrument features a robust internal MicroSD-based data logger.

Digital connectivity and analytical evaluation

The continuously recorded measurement series (including Leq, Lmax, Lmin) can be transferred to peripheral devices via the integrated RS-232 or USB interface in a tamper-proof manner. The large, backlit LCD display allows for immediate visual monitoring of sound pressure trends directly in the field, without the need to connect a PC. The seamless digital traceability of all acoustic parameters guarantees legally compliant documentation for regulatory noise control requirements or occupational health assessments.

Technical details

• Accuracy class 1 in accordance with IEC 61672-1
• Highly sensitive 1/2-inch free-field microphone (detachable)
• Frequency weighting filters A, C and Z (linear)
• Selectable time weightings: Fast, Slow and Impulse
• Integrated octave-band filter for frequency analysis
• Wide dynamic measurement range for sound pressure levels
• Calculation of Leq, Lmax, Lmin and other parameters
• High-contrast, backlit LCD display for live readouts
• Internal data logger via MicroSD memory card
• USB and RS-232 digital interfaces for PC connection
• Robust housing design for mobile field use
• Tripod socket on the rear of the unit

Contents of the pack

• 1 x SAUTER SW 1000 Class 1 sound level metre
• 1 x 1/2-inch free-field microphone
• 1 x Acoustic windscreen (foam)
• 1 x Sturdy carrying case
• 1 x MicroSD memory card
• 1 x USB data cable
• 1 x mains adaptor
• 1 x Detailed user manual

Individual requirements & accessories

To ensure legally compliant and standard-compliant measurements, a Class 1 sound level metre must be physically recalibrated before and after each significant series of measurements. We strongly recommend ordering a suitable acoustic calibrator (e.g. SAUTER BS 1) at the same time. For long-term measurements in a free field, we also recommend using a sturdy tripod. Our metrology-trained procurement service will be happy to configure a bespoke, ISO-certified measurement setup for you, including the necessary DAkkS calibration certificates.