Introduction
The COEUS-4G/WiFi temperature sensor from Freshliance is designed for real-time environmental monitoring in both static and mobile applications. Available in Wi-Fi and 4G versions, these IoT data loggers provide reliable temperature and humidity data with robust alerting, long battery life, and flexible deployment.
Features
24/7 Real-Time Remote Monitoring
COEUS-WiFi temperature sensor connects via WiFi—no SIM card or mobile data plan required. Ensures stable, cost-effective monitoring for indoor environments.
COEUS-4G real-time data logger automatically uploads data via a built-in 4G SIM card, with no need for Wi-Fi. Direct cellular connection enables seamless setup and real-time tracking, even in mobile or remote environments.
Optional External Probes
Supports two external probes with three optional sensor types:
Temperature & humidity probe: -30℃ to +70℃ / -40℃ to +85℃
Single temperature probe: -30℃ to +70℃
Ultra-low temperature probe: -90℃ to +190℃
Default probe cable length: 2 meters, customizable upon request.
combined with external probe to supply wide temperature monitoring range.
Ideal for cold rooms, incubators, or dry ice applications
Dual Monitoring System: App + Cloud Platform
Real-time access and remote configuration via both mobile app and cloud platform—no need for on-site manual checks
Rechargeable Battery
Equipped with a 2600mAh lithium battery, supports up to 90 days of operation (with 1-hour logging interval). Reliable during power outages.
Data Continuity
Even during WiFi or 4G disconnection, data is stored locally and auto-uploaded once the network is restored.
Instant Alerts
Receive SMS, email, and app push notifications via the internet.
Visual + audible alerts on the device: red flashing light + buzzer.
On-Demand Report Export
Supports temporary data export during active operation for compliance checks or quick reviews.
Specifications
Model | COEUS-WiFi | COEUS-4G |
Data Upload Network | WiFi | 4G |
Device Configuration Network | Device AP | 4G |
Maximum Power Consumption | ≤500mA | ≤800mA |
Built-in Sensor | -30℃ ~+ 60℃ ±0.5℃ F.S. |
0~100%RH (Non-condensing) At 25℃ ±2%RH typical ±3%RH (20%~80%RH) ±5%RH (Others) |
External Probes | See the External Probe List |
Logging Interval | 1min~2d |
Uploading Interval | 1min~2d |
Memory Capacity | 120,000 readings, circular buffer |
Main Power Supply | USB-Type C, 5V/2A (DC) |
Backup Battery | Rechargeable lithium battery, 2600mAh; Max. 60 days (Uploading interval: 15min) |
Alarm Mode | Audible and visual alarm |
Device Dimensions | 109mm(L)*33mm(W)*80mm(H) |
Screen Dimensions | 85mm*52mm |
Weight | 175g |
External Probe List:
Probe Type | Measuring Range | Measuring Accuracy |
Temperature Probe | -30℃~+70℃ | ±0.5℃ (-30℃~+50℃) ±1.0℃(Others) |
-90℃~+200℃ | ±0.3℃ (-40℃~+100℃) ±0.5℃ (-80℃~-40℃; +100℃~+150℃) ±1.0℃ (Others) |
Temperature and Humidity Probe | -40℃~+85℃ | ±0.5℃ F.S. |
0-100%RH | ±3%RH (25℃, 20%~90%RH) ±5%RH (Others) |
Standard cable length: 2m; Customizable length available: 5m, 10m, 15m or 20m. |
Application
COEUS series 4G/WiFi temperature sensor are mainly used for the temperature and humidity monitoring of cold rooms, especially the fridges and freezers. The fridge/freezer/refrigerator real-time data logger will automatically upload all monitoring data to the cloud via WiFi or 4G network accordingly. Besides, they have a large LCD screen to help users to intuitively view the current temperature and humidity, Max. and Min. temperature and humidity values, date and time, etc.
