UL90-GSM GSM-Based Ultra-Low Temperature Freezer Monitoring and SMS Alert System
| Brand | Truelab |
|---|---|
| Origin | Shanghai, China |
| Manufacturer Type | Authorized Distributor |
| Country of Origin | China |
| Model | UL90-GSM |
| Price | USD 570 (approx.) |
| Temperature Range | −90 °C to +40 °C |
| Temperature Accuracy | ±0.5 °C to ±0.8 °C |
| Temperature Resolution | 0.1 °C |
| Memory Capacity | 14,848 data points (expandable to 31,104) |
| Logging Interval | 2 seconds to 24 hours (user-configurable) |
| Power Supply | 12 V DC input with built-in rechargeable lithium battery (7-day backup during power outage) |
| Communication Interface | USB 2.0 |
| Average Power Consumption | ≤0.24 W |
| Alarm Triggers | Temperature out-of-range, power failure, configurable SMS alert interval (default 10 min) |
| SMS Recipients | Up to 3 mobile numbers |
| Network Compatibility | GSM only (not compatible with CDMA or LTE-only SIMs) |
| Operating Environment | −20 °C to +70 °C |
| Compliance | CE-marked for industrial environmental monitoring |
Overview
The UL90-GSM is a purpose-engineered environmental monitoring system designed specifically for continuous, unattended temperature surveillance in ultra-low temperature (ULT) storage environments. It operates on the principle of high-stability thermistor-based temperature sensing combined with embedded GSM cellular communication, enabling real-time remote monitoring and event-triggered SMS alerts without requiring local network infrastructure. Unlike generic data loggers, the UL90-GSM integrates three critical functions into a single robust enclosure: (1) continuous temperature logging at user-defined intervals, (2) instantaneous SMS notification upon power interruption, and (3) configurable threshold-based SMS alarms for temperature excursions. Its −90 °C to +40 °C operational range makes it uniquely suited for applications where cryogenic stability is non-negotiable—such as −86 °C biomedical freezers, vapor-phase liquid nitrogen storage units, dry ice transport containers, and refrigerated logistics vehicles. The device complies with fundamental requirements for cold chain integrity monitoring under ISO 14644-1 (cleanroom environmental control), ASTM D3103 (cold chain packaging validation), and supports documentation practices aligned with FDA 21 CFR Part 11 when used with validated software workflows.
Key Features
- GSM-based remote monitoring: No Wi-Fi or Ethernet required—operates independently via standard 2G GSM networks using a pre-inserted SIM card.
- Dual-power architecture: 12 V DC input charges an internal high-capacity lithium battery; maintains full functionality—including logging and SMS transmission—for up to 7 days during mains power failure.
- Triple-recipients SMS alerting: Configurable to notify up to three designated personnel simultaneously upon temperature deviation or power loss.
- User-adjustable alarm logic: Independent upper/lower temperature thresholds; programmable SMS retransmission interval (default 10 minutes) to prevent message flooding during sustained excursions.
- Real-time remote interrogation: Any authorized mobile phone can query current temperature, memory status, battery level, and signal strength via standardized SMS command syntax (e.g., “READ TEMP”).
- On-device visual and audible feedback: Dual-status LED indicators for network registration and alarm states; calibrated piezoelectric buzzer provides distinct acoustic signatures for successful initialization, valid command receipt, and communication errors.
- Expandable data retention: Standard 14,848-record memory (≈6 months at 15-minute logging); firmware-upgradable capacity to 31,104 records for extended archival compliance.
Sample Compatibility & Compliance
The UL90-GSM is validated for direct mounting inside ULT freezer chambers (−86 °C), insulated transport containers, and cold rooms with ambient operating limits from −20 °C to +70 °C. Its IP54-rated enclosure resists condensation ingress and mechanical abrasion typical in laboratory and logistics settings. While not intrinsically safe for explosive atmospheres, it meets EN 61326-1:2013 electromagnetic compatibility standards for industrial measurement equipment. For regulated environments, raw CSV log exports generated by the included Windows-compatible analysis software support traceable, time-stamped records suitable for internal QA audits and external inspections per ISO/IEC 17025 and EU Annex 15 guidelines. Note: GSM network registration requires a functional 2G SIM card with active voice/SMS service, caller ID enabled, and properly configured SMSC number—verified against regional carrier specifications (e.g., +8613800100500 for China Mobile).
Software & Data Management
The bundled Truelab LogView software (v3.2+) provides full configuration, data retrieval, and report generation capabilities. Users configure logging intervals, alarm thresholds, recipient numbers, and SMS center addresses via intuitive GUI dialogs. All parameters are stored redundantly—in device flash memory and locally encrypted project files—to ensure reproducibility across deployments. Exported datasets include UTC timestamps, sensor readings, battery voltage, signal strength (RSSI), and event flags (e.g., “POWER_LOSS”, “TEMP_HIGH”). Audit trail functionality logs every configuration change with operator ID and timestamp—critical for GLP/GMP-aligned laboratories requiring documented instrument control history. Software-generated PDF reports include calibration certificate references, statistical summaries (min/max/mean/stdev), and annotated excursion timelines—exportable for inclusion in SOP appendices or regulatory submissions.
Applications
- Continuous monitoring of −86 °C ultra-low temperature freezers storing stem cells, plasma, mRNA vaccines, and other thermolabile biologics.
- Validation and routine surveillance of dry ice shipping containers during clinical trial material distribution.
- Temperature mapping and alarm verification in pharmaceutical cold rooms compliant with USP <797> and <1079>.
- Backup monitoring layer for existing BMS systems in biorepository facilities—providing independent confirmation of thermal integrity.
- Field-deployable logging for remote research stations or mobile labs lacking stable internet connectivity.
FAQ
Does the UL90-GSM support 4G/LTE networks?
No. It operates exclusively on legacy 2G GSM networks (900/1800 MHz bands). Verify local carrier 2G coverage before deployment.
Can I disable SMS alerts while retaining local logging?
Yes. The front-panel button toggles SMS functionality on/off without affecting data acquisition or internal memory operations.
What happens if the SIM card balance is depleted?
SMS alerts will fail silently; however, temperature logging continues uninterrupted. The device logs failed transmission events internally and reports low-balance status via SMS upon next successful transmission.
Is calibration certificate included?
A factory calibration report (NIST-traceable reference) is supplied with each unit. Field recalibration is supported via optional PT100 probe interface (sold separately).
How is data security handled during USB transfer?
No encryption is applied to USB-transferred CSV files. Users must implement local file access controls per organizational IT policies. The software does not store passwords or transmit data externally.
