COMET U3631G – IoT Wireless Datalogger with 4G Modem, Internal Temperature and Humidity, External Pt1000 Sensor

COMET U3631G – IoT Wireless Datalogger with 4G Modem, internal T+RH (-20 to +60 °C ±0.4 °C / 0–100 %RH ±1.8 %), external Pt1000 (-90 to +260 °C ±0.2 °C), dew point, SMS/JSON alarm 

The COMET U3631G is a modern IoT wireless datalogger with an integrated 4G modem (LTE Cat 1, FDD/GSM/GPRS/EDGE) – the autonomous and network-independent solution for remote monitoring and long-term recording of temperature, relative humidity, and dew point using internal sensors plus an external Pt1000 temperature probe. Whether for cold chain logistics, warehouses, climate chambers, server rooms, greenhouses, compressors, dryers, pharmaceutical production, or remote sites – the U3631G sends instant SMS and JSON alarms via 4G when alarm limits are exceeded. Regular JSON data transmission to the COMET Database or COMET Cloud (a complete monitoring, alarm, and analysis tool) can be configured. Local alarms are indicated via LED, LCD, and buzzer. With storage for 1 million data points (non-cyclic) or 600,000 values (cyclic) and a traceable calibration certificate (EN ISO/IEC 17025), it is ideal for quality management, audits, and ISO compliance.

The internal sensors measure temperature from -20 to +60 °C (±0.4 °C) and humidity from 0 to 100 %RH (±1.8 %RH). The dew point is calculated automatically (-90 to +60 °C, ±1.5 °C at T<25 °C and RH>30 %). The external Pt1000 input measures -90 to +260 °C (±0.2 °C from -50 to +100 °C, ±0.2 % of reading above that, ±0.4 % from -90 to -50 °C). The acoustic and visual alarms provide immediate warnings when freely adjustable limits are exceeded. Minimum and maximum values are stored. The backlit LCD display is easy to read, and both the measuring rate (0.7 to 5 s) and display refresh rate can be adjusted. The logger operates completely autonomously using its internal battery – no external power supply required. Data can be downloaded to a PC via USB‑C. COMET Cloud: 3 months free included, then 1 credit per year. Supported LTE FDD B1/B3/B5/B7/B8/B20 and GSM 900/1800 MHz bands ensure global coverage and stable data transmission.

The datalogger is maintenance-free, long-term stable, and covered by a 3‑year warranty. The supplied traceable calibration certificate guarantees maximum measuring accuracy from the factory. Configuration is intuitive via LCD or COMET Cloud. Whether used as a mobile remote logger on construction sites, a stationary monitor in remote installations, or a central device in production – the U3631G impresses with precision, autonomy, 4G connectivity, and ease of use. The external Pt1000 probe (sold separately) enables measurements in pipes, ducts, or confined spaces.

Why the COMET U3631G is the best IoT 4G datalogger for T+RH with external probe:

• Integrated 4G modem (LTE Cat 1) – SMS/JSON alarm & data transmission without WLAN/LAN
• Internal T+RH sensors + external Pt1000 input – dual temperature measurement
• 1 million data point memory – non-cyclic or cyclic
• COMET Cloud – full monitoring, alarm & analysis (3 months free)
• Acoustic/visual alarm + LED – instant on-site warning
• Dew point & all humidity parameters – automatically calculated
• Backlit LCD – all values visible at a glance
• Traceable calibration certificate included – EN ISO/IEC 17025
• Battery powered – no external power supply required
• 3‑year warranty – guaranteed COMET quality

Technical data U3631G:

• Internal temperature: −20 to +60 °C (±0.4 °C)
• External temperature (Pt1000): −90 to +260 °C (±0.2 °C from −50 to +100 °C / ±0.2 % above / ±0.4 % from −90 to −50 °C)
• Internal humidity: 0 to 100 %RH (±1.8 %RH)
• Dew point: −90 to +60 °C (±1.5 °C at T<25 °C and RH>30 %)
• Resolution: 0.1 °C / 0.1 %RH / 0.1 °C dew point
• Alarm: acoustic + visual + SMS/JSON via 4G
• Memory: 1,000,000 values (non-cyclic) / 600,000 values (cyclic)
• Logging interval: 1 s to 24 h
• Measurement interval / display refresh: 0.7 to 5 s
• Display: backlit LCD
• Communication: 4G modem (LTE FDD B1/B3/B5/B7/B8/B20 + GSM/GPRS/EDGE 900/1800 MHz) + USB‑C
• Power supply: internal battery (lifetime depending on configuration – several months/years)
• Operating temperature: −10 to +60 °C
• Protection class: IP20 (device)
• Warranty: 3 years

Perfect for:

• Cold chain & transport monitoring (remote temperature & humidity)
• Warehouse and cold storage monitoring at remote sites
• Compressed air systems & compressors (remote humidity)
• Pharmaceutical and food production
• Greenhouses & agriculture
• Server rooms and data centers
• Remote monitoring without local internet
• Quality management & audits

Installation and operation – done in minutes

Connect the external Pt1000 probe, insert the SIM card (if required), activate the battery – finished! Set intervals, limits, and Cloud/SMS settings, start logging – read out the data via COMET Cloud or USB‑C. The backlit display and acoustic alarm make operation safe and convenient. Calibration certificate included – ideal for audits and quality management.

Summary:

• The 4G datalogger records temperature and humidity via internal sensors and temperature via an external probe
• If preset limits are exceeded, SMS and JSON messages are sent via the 4G data connection
• Measured values can be transmitted to COMET Cloud, a comprehensive monitoring, alarm, and analysis system
• Regular transmission of JSON messages to the COMET database can be configured; transmission interval is adjustable
• Alarms are indicated locally by LED, LCD, and an integrated acoustic signal
• Data is recorded in non-volatile electronic memory
• Data can be transferred to a PC via the supplied USB‑C cable
• The 4G recorder includes a traceable calibration certificate with declared metrological traceability of standards according to EN ISO/IEC 17025 requirements.

Scope of delivery:

• U3631G
• User manual
• Traceable calibration certificate
• Battery
• Power adapter
• USB‑C cable
• Free full version of COMET Vision analysis software
• COMET Cloud for 3 months
• External probes are not included
• SIM card not included