COMET U0121M – IoT Wireless Datalogger with 2G modem, 2× external Pt1000 probe

COMET U0121M – IoT Wireless Datalogger with 2G Modem, 2× External Pt1000 Probe (-200 to +260 °C ±0.2 °C), 500,000 Data Memory, SMS/JSON Alarm 

The COMET U0121M is a professional IoT wireless datalogger with an integrated 2G modem (quad-band GSM/GPRS) – an autonomous and network-independent solution for remote monitoring and long-term recording of temperature using two external Pt1000 probes. Whether for cold chains, warehouses, climate chambers, cold rooms, transport, pharmaceutical production, food industry, server rooms, or remote sites – the U0121M immediately sends SMS and JSON alarms via GPRS when preset limits are exceeded. Regular JSON data transmission to COMET Database or COMET Cloud (a complete monitoring, alarm, and analysis tool) can be configured. Local alarms are indicated by LED, LCD, and buzzer. With storage for 500,000 records (non-cyclic) or 350,000 records (cyclic) and a traceable calibration certificate (EN ISO/IEC 17025), it is ideal for quality management, audits, temperature mapping, and ISO compliance.

The two external Pt1000 inputs measure temperature from -200 to +260 °C (±0.2 °C from -50 to +100 °C, ±0.2 % of reading above that). The acoustic and optical alarms provide instant warning if adjustable limits are exceeded. Min/Max values are stored. The backlit LCD displays both channels simultaneously. The logger operates fully autonomously with an internal battery – no external power supply required. Data can be downloaded to a PC via USB‑C. COMET Cloud: 3 months free, then 1 credit per year. The quad-band GSM modem (850/900/1800/1900 MHz) ensures worldwide coverage and stable data transmission.

The datalogger is maintenance-free, long-term stable, and includes a 3-year warranty. The supplied traceable calibration certificate ensures maximum measurement accuracy directly from the factory. Intuitive configuration via LCD or COMET Cloud. Whether used as a mobile remote logger in transport vehicles, a stationary monitor in cold rooms, or a central device in production, the U0121M impresses with precision, autonomy, 2G connectivity, and ease of use. The two Pt1000 inputs enable differential measurements (e.g., supply/return or product/ambient).

Why the COMET U0121M is the best IoT 2G datalogger for dual Pt1000 sensors:

• Integrated 2G modem (quad-band GSM/GPRS) – SMS/JSON alarm & data transfer without Wi‑Fi/LAN
• 2× external Pt1000 inputs – dual temperature measurement for differential or redundant monitoring
• 500,000 data memory – non‑cyclic or cyclic
• COMET Cloud – full monitoring, alarm & analysis (3 months free)
• Acoustic/optical alarm + LED – immediate local alert
• Wide measuring range – -200 to +260 °C (±0.2 °C in the core range)
• Backlit LCD – simultaneous display of both channels
• Traceable calibration certificate included – EN ISO/IEC 17025
• Battery‑powered operation – no external power supply required
• 3‑year warranty – guaranteed COMET quality

Technical data U0121M:

• External temperature (Pt1000): -200 to +260 °C (±0.2 °C from -50 to +100 °C / ±0.2% above)
• Resolution: 0.1 °C
• Channels: 2× external Pt1000
• Alarm: acoustic + optical + SMS/JSON via GPRS
• Memory: 500,000 values (non‑cyclic) / 350,000 values (cyclic)
• Internal logging interval: 1 s to 24 h
• COMET Cloud logging interval: from 5 minutes
• Measurement/alarm evaluation interval: adjustable 1 s, 10 s, 1 min
• Display: backlit LCD
• Communication: 2G modem (quad‑band 850/900/1800/1900 MHz, GPRS Class B) + USB‑C
• Power supply: internal battery (lifetime depends on configuration – several months/years)
• Operating temperature: -20 to +60 °C
• Protection rating: IP67 (device)
• Warranty: 3 years

Perfect for:

• Cold chain & transport monitoring (differential measurement remotely)
• Warehouse and cold room monitoring at remote sites
• Pharmaceutical and food production
• Climate chambers and incubators
• Product vs. ambient temperature (dual‑channel)
• Quality management & audits
• Autonomous long‑term logging without mains connection
• Mobile inspection and service

Setup and operation – done within minutes

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

Summary:

• The GSM datalogger is designed for temperature measurement with two external Pt1000 probes
• When set limits are exceeded, SMS and JSON alerts are sent via a GPRS data connection
• Measured values can be transmitted to the online storage COMET Cloud – a complete monitoring, alarm, and analysis system
• Regular transmission of JSON data to the COMET Database can also be configured; the sending 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 device includes a traceable calibration certificate ensuring metrological traceability according to EN ISO/IEC 17025
• When purchasing a new IoT wireless datalogger with integrated modem, 3 months of COMET Cloud are included free; for one full year of use, 1 credit is required thereafter. 

Scope of delivery:

• U0121M
• User manual
• Traceable calibration certificate
• Rechargeable battery
• Power adapter 
• USB‑C cable 
• Free full version of COMET Vision analysis software 
• COMET Cloud for 3 months 
• External probes not included
• SIM card not included