Kestrel DROP D2 Temperature & Humidity Data Logger

Overview

The Kestrel DROP D2 is a compact, ruggedized, multi-channel temperature and humidity data logger engineered for long-term environmental monitoring in demanding field, industrial, logistics, and laboratory settings. Unlike traditional wired loggers or bulkier wireless alternatives, the DROP D2 employs a sealed, externally mounted thermistor and capacitive humidity sensor—thermally isolated from the main housing—to ensure rapid thermal response and high measurement stability across its full operating range of –10°C to +55°C (14°F to 131°F). Its measurement accuracy of ±0.5°C (±0.9°F) for temperature and ±3% RH (typical) for relative humidity meets requirements for ambient condition validation in cold chain transport, storage facility qualification, HVAC performance verification, and environmental compliance documentation. The device operates autonomously on a single replaceable CR2032 lithium coin cell, supporting up to four months of continuous logging under typical sampling intervals (e.g., 1–15 min), and stores over 7,000 timestamped dual-parameter records internally.

Key Features

• Ruggedized enclosure certified to IP67 (30-minute submersion at 1 m depth) and MIL-STD-810G for mechanical shock resistance (1 m drop onto concrete)
• Compact form factor (24 × 46 × 60 mm; 34 g) with integrated D-ring for flexible mounting—ideal for confined spaces, shipping containers, incubators, or outdoor enclosures
• Bluetooth® Low Energy (BLE) 4.0 connectivity enabling secure, low-power wireless data retrieval within 30 m (100 ft) line-of-sight
• Simultaneous connection to up to eight DROP D2 units via the Kestrel LiNK mobile application—no gateway or cloud subscription required
• User-configurable logging interval (2 seconds to 12 hours), real-time threshold alarms, and automatic time synchronization upon each mobile device connection
• On-device data visualization including min/max/average values, scrollable time-series charts, and export-ready CSV reports via email or local file transfer

Sample Compatibility & Compliance

The DROP D2 is designed for non-invasive, ambient air monitoring only—its external sensor configuration avoids internal thermal mass effects and enables accurate tracking of transient environmental shifts. It does not support immersion, pressurized gas, or corrosive vapor environments. While not certified to ISO/IEC 17025 or accredited for metrological traceability, its sensor performance aligns with common industrial benchmarks referenced in ASTM E145 (Standard Specification for Gravity-Convection and Forced-Ventilation Ovens), ISO 14644-1 (Cleanroom classification), and USP (Good Storage and Distribution Practices). The device supports audit-ready data integrity through immutable timestamps, user-defined alarm logs, and full export history—facilitating adherence to internal SOPs and GLP-aligned documentation workflows.

Software & Data Management

Kestrel LiNK is a free, platform-native application (iOS and Android) developed exclusively for DROP-series loggers. It provides full local control without mandatory cloud upload or account registration. All raw data remains stored on the mobile device until explicitly exported. The app enforces secure BLE pairing, displays real-time sensor status (battery level, memory usage, connection strength), and allows granular configuration of logging parameters—including custom start/stop triggers and alarm hysteresis settings. Export options include timestamped CSV files with UTC/GMT timestamps, compatible with Excel, MATLAB, LabVIEW, and LIMS integration via drag-and-drop import. No proprietary file formats or vendor-locked analytics are used—ensuring long-term data accessibility and interoperability.

Applications

• Cold chain validation: Monitoring temperature excursions during pharmaceutical, vaccine, or food transport and warehouse storage
• HVAC system commissioning and seasonal performance trending in commercial buildings and cleanrooms
• Museum and archive environmental stewardship per ISO 11799 guidelines for preservation conditions
• Agricultural microclimate profiling in greenhouses, grain silos, and post-harvest drying facilities
• Field-deployed environmental baselines for construction site dust and moisture control plans
• Educational labs requiring affordable, portable, and repeatable environmental data collection platforms

FAQ

Does the DROP D2 require a subscription or cloud service to function?
No. All data logging, configuration, and export occur locally via Bluetooth. No internet connection or recurring fees are needed.
Can multiple users access the same DROP D2 simultaneously?
No—only one mobile device can maintain an active BLE connection at a time. However, historical data can be exported and shared freely.
Is the battery replaceable by the end user?
Yes. The CR2032 coin cell is field-replaceable using standard tools; no soldering or calibration recalibration is required after replacement.
What happens if the Bluetooth connection is lost during logging?
The device continues logging autonomously. No data is lost—the full internal memory buffer remains intact until the next successful connection.
Does the DROP D2 meet FDA 21 CFR Part 11 requirements?
It does not provide electronic signature capability or audit-trail encryption out of the box. However, exported CSV files may be incorporated into validated systems that implement Part 11 controls at the enterprise level.