FNIRSI FDM01 Noise Decibel Meter

FNIRSI FDM01 Noise Decibel Meter

The FNIRSI FDM01 is a compact decibel meter designed to measure noise levels ranging from 30 to 130 dB while simultaneously monitoring temperature and humidity. It features a sensitive 6 mm condenser microphone, a 2.3-inch VA color display with backlight, and a rechargeable 600 mAh lithium battery charged via USB-C. Its fast response time, multiple measurement modes (MIN/AVG/MAX), light alarm, and selectable detection modes (FAST/SLOW) make it suitable for use in offices, construction sites, transportation, production rooms, and public spaces.

Precision Measurement Microphone

The device uses a 6 mm condenser microphone characterized by high sensitivity and rapid response. Constructed with nickel-plated steel, a three-layer conductive structure, and silicone seals, it effectively isolates interference and ensures reliable results even during sudden volume spikes. Users can select between FAST (1 second) and SLOW (1.25 seconds) measurement modes to adapt to dynamic or stable noise environments.

Measurement in A-Weighting Mode

The FNIRSI FDM01 employs the A-weighting frequency characteristic, which aligns with human ear sensitivity across frequencies. It measures sound in the range of 31.5 Hz to 8.5 kHz, enabling accurate assessment of environmental noise levels according to standard practices.

Light Alarm and Value Hold Function

The device features a red alarm light that activates when the preset sound threshold is exceeded. It can display minimum, average, or maximum values to facilitate result documentation. The HOLD function allows users to freeze the current reading on the screen for convenience.

Easy-to-Read Screen and Durable Housing

The 2.3-inch VA display provides clear visibility of all data even in bright lighting conditions. The housing is made of durable ABS plastic with silicone buttons, enhancing robustness for field and industrial use. A soft wind shield reduces ambient noise interference during measurements. The built-in 600 mAh lithium battery eliminates the need for disposable batteries and is conveniently rechargeable via USB-C, reducing operational costs.

Included Items

• FNIRSI FDM01 decibel meter
• Charging cable

Specifications

• Manufacturer: FNIRSI
• Model: FDM01
• Accuracy: ±1.5 dB (based on NV sound source 94 dB at 1 kHz)
• Frequency Range: 31.5 Hz – 8.5 kHz
• Dynamic Range: 3.50 dB
• Measurement Range: 30 – 130 dB
• Frequency Weighting: A-weighting curve
• Digital Display: 4 digits, resolution 0.1 dB, refresh rate 2 times per second
• Dynamic Scale Display: 1 division = 2 dB, refresh rate 2 times per second
• Dynamic Scale Range: 30 – 130 dB
• Overload Indication: Displays "OVER" or "UNDER" symbols
• Dynamic Characteristics: FAST (1 sec), SLOW (1.25 sec)
• Microphone: 6 mm condenser microphone
• Maximum Value Retention: MAX function
• Battery: Rechargeable lithium battery, 600 mAh / 3.7 V
• Operating Temperature and Humidity: 0°C to 40°C, 10% to 80% RH
• Storage Temperature and Humidity: -10°C to 60°C, 10% to 70% RH