COMET W3721 – WiFi Sensor for 2 External Temperature/Humidity Probes

COMET W3721 WiFi T+RH Sensor 2 external probes 

The COMET W3721 is the powerful WiFi sensor for measuring temperature and relative humidity using up to two external Digi/E probes – the ideal solution for precise, wireless multi-point climate monitoring in warehouses, greenhouses, server rooms, museums, production halls, or anywhere multiple measurement points need to be monitored via WiFi connectivity. The external probes (available optionally) allow flexible placement in hard-to-reach or extreme environments while keeping the housing protected.

Simply place it, connect to WiFi – and the W3721 automatically sends measurement data from both channels to the COMET Cloud (from a 5-minute interval) or to your own system. The maintenance-free sensor measures with high accuracy and calculates dew point, absolute humidity, specific humidity, mixing ratio, and specific enthalpy. If a limit value is exceeded on one or both channels, the sensor issues an alert via email, audible signal, or visually on the LCD display – with two freely adjustable alarm thresholds per channel.

Values can be displayed via integrated web pages or forwarded to third-party systems using Modbus TCP, SNMP, JSON, or XML. With the free COMET Cloud (3 months free, then 1 credit/year), you get a complete monitoring solution without your own server: charts, exports, alarms, and remote access via app or browser.

The robust housing, large LCD display, and simple setup via WPS or web interface make the W3721 the ideal multi-channel sensor for smart building, Industry 4.0, and professional monitoring – made by COMET.

Why the COMET W3721 is the smart choice for 2-channel monitoring:

• 2 external Digi/E probes – flexible for different measuring points
• WiFi connectivity – uses existing infrastructure
• COMET Cloud included – 3 months free, then low-cost credit
• Protocols: Modbus TCP, SNMP, JSON, XML – open for third-party systems
• Email alarm + acoustic/visual alerts – immediate notification per channel
• Large LCD display – local display of both channels
• Precise measurement – accuracy depends on probe
• Dew point & all humidity parameters integrated
• Easy setup – WPS or web interface
• 3-year warranty

Technical data:

• Temperature measuring range: depends on connected Digi/E probe
• Temperature accuracy: depends on probe
• Temperature resolution: 0.1 °C
• Humidity measuring range: depends on connected Digi/E probe
• Humidity accuracy: depends on probe
• Humidity resolution: 0.1 %RH
• Dew point: depends on probe
• WiFi: 2.4 GHz, IEEE 802.11 b/g/n
• Cloud interval: adjustable from 5 minutes to 12 hours
• Protocols: HTTP(S), SMTP, Modbus TCP, SNMP (v1,v2c,v3), HTTP POST/GET (JSON, XML)
• Alarm: Email, acoustic (buzzer), visual (LED/display)
• Display: LCD with backlight
• Power supply: AC adapter (included)
• Operating temperature: –30 to +60 °C
• Ingress protection: IP30
• Warranty: 3 years

Perfectly suited for:

• Multi-point monitoring in warehouses and cold chains
• Server rooms and data centers (multiple zones)
• Museums, archives, and libraries
• Greenhouses and agriculture
• Offices, schools, kindergartens
• Pharma storage and cold rooms
• Production areas and quality control
• Industry 4.0 and IoT applications

Setup – completed in minutes

Connect the sensor, attach the probes, connect to WiFi (WPS or app), activate COMET Cloud – done. Measurement data from both channels automatically flow into the cloud or your own system.

Summary:

• Sensors with WiFi interface measure temperature and relative humidity with two connected probes (optional accessories).
• Communication with the sensor is wireless via WiFi.
• The device allows sending measured values to the COMET Cloud (with a minimum interval of 5 minutes) or to the COMET database.
• Values can be displayed on integrated web pages and transmitted to third-party systems via Modbus TCP, SNMP, JSON, and XML.
• Measurements are displayed on the LCD display.

Scope of delivery:

• W3721
• User manual
• Traceable calibration certificate
• Power supply adapter
• USB-C cable
• COMET Cloud for 3 months
• EXTERNAL PROBES ARE NOT INCLUDED