Bruel & Kjaer Type 2240 - Sound Level Meter
Description
A low-cost, Class 1 sound level meter conforming to international standards. The three-button user-interface and large digital display make it easy to use for on-the-spot measurements. Equipped with a Type 4188 microphone, it simultaneously measures all of the most important environmental noise parameters over a measurement period from 1 second to 60 minutes.
Features
- Class 1 measurement precision conforming to the latest standards
- LAeq, LAFmax, LCpeak, LAF
- Dynamic range: 30 – 140 dB in two 80 dB ranges
- Handy and lightweight
- Large and clear display
- 16 hour battery life from two AA cells
Specifications
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STANDARDS |
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Conforms with the following: |
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• IEC61672 – 1:2002 Class 1 |
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• IEC60651 Type 1 (1979) with amendments 1 and 2 |
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• IEC60804 Type 1 (2000) |
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• ANSIS1.4 – 1983 Type S1 |
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• ANSIS1.43 – 1997 Type 1 |
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PARAMETERS |
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Four parameters are measured simultaneously: |
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• LAF, instantaneous sound pressure level, frequency weighting ‘A’ and time weighting ‘F’ |
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• LAFmax, maximum sound pressure level, frequency weighting ‘A’ and time weighting ‘F’ |
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• LAeq, equivalent continuous sound pressure level, frequency weighting ‘A’ |
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• LCpeak, maximum peak sound pressure level, frequency weighting ‘C’ |
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Resolution: 0.1 dB for all four parameters |
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MEASUREMENT CONTROL |
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Measurements are manually controlled |
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Measurement times between 1 s and 60 min |
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MEASURING RANGES |
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RMS: Total range: 30 – 140 dB |
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Two manually selected ranges: 30 – 110 dB and 60 – 140 dB |
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Peak: 60 – 143 dB |
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NOISE FLOOR |
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Below measurement range, < 22 dB |
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DETECTORS |
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Simultaneous RMS and Peak with independent frequency weightings |
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Linear Operating Range: 80 dB |
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FREQUENCY RANGE |
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20Hz to 16 kHz |
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FREQUENCY WEIGHTINGS |
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A-weighting (RMS) |
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C-weighting (Peak) |
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TIME WEIGHTING |
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‘F’ (Fast) |
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OVERLOAD AND UNDER-RANGE INDICATORS |
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Overload is indicated at full-scale +0.3 dB |
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An overload detected during a timed measurement latches and is displayed with the relevant parameters until these are cleared Under-range is indicated at scale lower limit –0.5 dB |
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MICROPHONE |
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Type 4188 Prepolarized Free-field 1/2″ Condenser Microphone |
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Sensitivity: –30 dB re 1V/Pa } 2 dB (corresponding to 31.6mV/Pa) |
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Frequency Range: 8Hz to 16 kHz }2dB |
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DISPLAY |
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LCD showing: |
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• Input signal level – indicated with a quasi-analogue bar |
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• Selected parameters with level |
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• Warnings for: low battery, measurement in progress, overload and under-range |
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• Measuring range |
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• Frequency and time weighting |
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• Elapsed measurement time |
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Update Cycle: 1 s (numeric), 0.1 s (bar graph) |
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Elapsed Time Display: from 00 min 00 s up to 60 min 00 s |
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SETTLING TIME |
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Less than 5 s |
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REFERENCE CONDITIONS |
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Reference Frequency: 1000 Hz |
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Reference Sound Pressure Level: 94 dB |
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Reference Temperature: 20°C (68°F) |
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Reference RH: 65% |
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Reference Range: 30 – 110 dB |
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Reference Direction of Incidence: Frontal |
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ENVIRONMENTAL EFFECTS |
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Storage Temperature: –25 to 60°C (–13 to 140°F) |
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Operating Temperature: –10 to 50°C (14 to 122°F) |
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Effect of Magnetic Field: 80 A/m (1 oersted) at 50 Hz gives less than 30 dB (A-weighted) |
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BATTERIES |
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Two 1.5 V LR 6/AA-size alkaline batteries |
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Power Consumption During Normal Operation: Less than 300mW |
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Lifetime (at room temperature): Approximately 16 h |
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PHYSICAL CHARACTERISTICS |
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Dimensions: 230 × 78 × 31 mm including microphone |
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Weight: 245 g (8.64 oz) including batteries |
