COMET U4440 – Data Logger for Temperature, Humidity, CO₂ & Air Pressure

COMET U4440 – robust data logger with internal sensors (-20 to +60 °C ±0.4 °C / 0–100 %RH ±1.8 % / CO₂ 0–5000 ppm ±(50 ppm+3%) / 700–1100 hPa ±1.3 hPa), dew point 

The COMET U4440 is a highly precise and compact data logger with integrated sensors for temperature, relative humidity, CO₂, and barometric pressure – the ultimate all-in-one solution for autonomous long-term monitoring and documentation of complete indoor air quality in offices, schools, kindergartens, hospitals, server rooms, warehouses, conference rooms, residential spaces, greenhouses, pharmaceutical areas, or anywhere temperature, humidity, CO₂ concentration, and air pressure need to be recorded without external probes. With a large memory capacity of 500,000 values (non-cyclic) or 350,000 values (cyclic), freely adjustable logging interval (1 s to 24 h), and a traceable calibration certificate (EN ISO/IEC 17025), it is perfect for quality management, audits, workplace monitoring, health protection, and ISO compliance.

The internal temperature sensor measures -20 to +60 °C (±0.4 °C), the humidity sensor 0 to 100 %RH (±1.8 %RH), the CO₂ sensor 0 to 5000 ppm (±(50 ppm + 3 % of reading) at 25 °C and 1013 hPa), and the barometric pressure sensor 700 to 1100 hPa (±1.3 hPa at 23 °C). The dew point is automatically calculated (-60 to +60 °C, ±1.5 °C at T<25 °C and RH>30 %). Acoustic and visual alarms (buzzer + LED) immediately warn when user-defined limits are exceeded. Min/Max values are stored. The backlit LCD display is easy to read, and measurement/alarm update intervals can be set (1 s, 10 s, 1 min). The logger operates autonomously with a 3.6 V AA lithium battery – lifetime of several years depending on the interval. No power supply required – ideal for fixed and mobile installations. Logging is possible as non-cyclic (stops when full) or cyclic (overwrites oldest data). Real-time clock with date/time. Data transfer via USB-C to a PC (COMET Vision software).

The data logger is maintenance-free, long-term stable, and comes with a 3-year warranty. The included traceable calibration certificate guarantees highest measurement accuracy from the factory. Intuitive operation via keys and clear menu. The compact housing (61 x 93 x 32 mm) makes it unobtrusive and easy to mount. Whether used as a standalone logger in production, as a mobile tester in service, or as a fixed component in indoor air monitoring, the U4440 impresses with precision, durability, and ease of use. No external probe required – ready for immediate indoor measurements.

Why the COMET U4440 is the best data logger for temperature + humidity + CO₂ + pressure:

• Internal sensors for temperature + humidity + CO₂ + air pressure – ready to use without probe
• 500,000 value memory – non-cyclic or cyclic
• Adjustable logging interval – 1 s to 24 h
• Acoustic & visual alarm – instant warning when limits are exceeded
• Min/Max memory – extreme values for all parameters
• Backlit LCD – displays temperature, humidity, CO₂, pressure, and status
• Traceable calibration certificate included – EN ISO/IEC 17025
• Autonomous battery operation – lithium AA, lifetime of several years
• USB-C data transfer – easy reading via COMET Vision
• 3-year warranty – guaranteed COMET quality

Technical data U4440:

• Temperature internal: -20 to +60 °C (±0.4 °C)
• Humidity internal: 0 to 100 %RH (±1.8 %RH)
• CO₂ internal: 0 to 5000 ppm (±(50 ppm + 3 % of reading) at 25 °C and 1013 hPa)
• Air pressure internal: 700 to 1100 hPa (±1.3 hPa at 23 °C)
• Dew point: -60 to +60 °C (±1.5 °C at T<25 °C and RH>30 %)
• Resolution: 0.1 °C / 0.1 %RH / 1 ppm CO₂ / 0.1 hPa / 0.1 °C dew point
• Channels: internal sensors for temperature, humidity, CO₂ and pressure
• Memory: 500,000 values (non-cyclic) / 350,000 values (cyclic)
• Logging interval: 1 s to 24 h
• Measurement/alarm update rate: adjustable 1 s, 10 s, 1 min
• Alarm: acoustic (buzzer) + visual (LED) when limit exceeded
• Display: backlit LCD
• Power supply: lithium battery 3.6 V AA
• Operating temperature: -20 to +60 °C
• Protection: IP20
• Dimensions: 61 x 93 x 32 mm
• Weight (incl. battery): approx. 120 g
• Warranty: 3 years

Perfect for:

• Indoor air quality in offices, schools & hospitals
• Server rooms and data centers
• Warehouse and cold storage monitoring
• Pharmaceutical and food production
• Climate chambers and incubators
• Greenhouses & agriculture
• Quality management & audits
• Autonomous long-term logging without mains connection

Installation and operation – done in minutes

Insert the battery – that’s it! Set intervals and limits, start logging – read data via USB-C. The illuminated display and acoustic/visual alarm make operation safe and convenient. Calibration certificate included – ideal for audits and quality management.

Summary:

• The data logger records temperature, humidity, air pressure, and CO₂
• When defined limits are exceeded, an LED, LCD, and acoustic signal alert
• Data is stored in non-volatile electronic memory
• Data can be transferred to a PC via USB-C
• The data logger includes a traceable calibration certificate confirming the metrological traceability of the standards according to EN ISO/IEC 17025 requirements. 

Scope of delivery: 

• U4440 
• User manual 
• Traceable calibration certificate 
• Battery 
• Power supply unit 
• USB-C cable 
• Free full version of the COMET Vision analysis software