Truelab BT-2 Laboratory Digital Thermo-Hygrometer with Large LCD Display

Overview

The Truelab BT-2 is a compact, benchtop digital thermo-hygrometer engineered for routine environmental monitoring in laboratory, quality control, cold storage, and general facility management settings. It operates on the principle of resistive humidity sensing (capacitive polymer sensor) combined with precision thermistor-based temperature measurement. The device features dual temperature inputs—one internal sensor for ambient chamber or room conditions, and one external probe (included) for remote or surface temperature sampling—enabling simultaneous comparative readings critical for stability studies, incubator validation, and HVAC verification. Its large-format LCD display ensures legibility at viewing angles up to 60°, supporting ergonomic placement on lab benches, inside refrigerated units, or mounted on walls via optional accessories. Designed for continuous unattended operation, the BT-2 delivers stable, repeatable measurements without calibration drift under typical indoor laboratory conditions (20–25 °C, 40–60% RH).

Key Features

• Dual independent temperature channels: internal sensor (–30 °C to +50 °C) and external thermistor probe (–50 °C to +70 °C), enabling spatial thermal profiling
• Relative humidity measurement across 20–99% RH range using a factory-calibrated capacitive polymer sensor with long-term stability
• High-contrast 81.5 × 64.5 mm LCD with segmented digits and icon-driven interface—no backlight required for daylight readability
• Min/Max memory function for both temperature and humidity; user-initiated reset preserves data integrity during shift handovers
• Integrated real-time clock with 12/24-hour format and programmable alarm—supports time-stamped logging when paired with external recording systems
• Unit toggle between °C and °F without recalibration; resolution maintained at 0.1 °C/°F for temperature and 1% RH for humidity
• Low-power design: single AAA battery provides ≥12 months of continuous operation under typical usage (display active, no alarm cycling)

Sample Compatibility & Compliance

The BT-2 is intended for non-invasive, ambient air monitoring only. It is not rated for use in explosive atmospheres (ATEX/IECEx), high-pressure enclosures, or corrosive gas environments (e.g., chlorine, H₂S). The external probe’s PVC-insulated cable (1.2 m standard length) is compatible with most Class 1000–100,000 cleanroom environments per ISO 14644-1 when used with appropriate gowning protocols. While the instrument does not carry formal ISO/IEC 17025 accreditation, its ±1 °C temperature and ±5% RH accuracy specifications align with general-purpose monitoring requirements defined in ISO 14644-3 Annex B (environmental monitoring of cleanrooms) and ASTM E2237–22 (Standard Guide for Monitoring Environmental Conditions in Cleanrooms). It supports GLP-compliant documentation when used in conjunction with controlled logbooks or validated electronic data capture systems.

Software & Data Management

The BT-2 operates as a standalone instrument with no embedded Bluetooth, USB, or wireless connectivity. All data are displayed in real time and retained in volatile memory only—no internal storage or timestamped history is maintained beyond the current Min/Max values and clock state. For regulatory traceability, users must manually record readings or integrate the unit into third-party data acquisition platforms via analog output adapters (not included). When deployed in FDA-regulated environments, the device may serve as a secondary monitor alongside primary validated systems, provided its use is documented in SOPs and its calibration status (annual verification recommended) is tracked per 21 CFR Part 11 principles for ancillary equipment.

Applications

• Environmental qualification of stability chambers, refrigerators, and cold rooms per ICH Q5C guidelines
• Baseline monitoring of laboratory ambient conditions during analytical method validation (USP <1058>)
• Pre-shipment verification of temperature-sensitive reagents and reference standards
• Supporting ISO/IEC 17025 clause 6.4.10 (monitoring of environmental conditions affecting measurement uncertainty)
• Facility maintenance logs for HVAC performance trending in GMP manufacturing suites
• Educational labs requiring robust, low-cost instrumentation for teaching metrology fundamentals

FAQ

Does the BT-2 require periodic calibration?
Yes. While factory-calibrated, Truelab recommends annual verification against NIST-traceable references—particularly before critical qualification studies. Internal sensor drift is typically <0.2 °C/year under stable conditions.
Can the external probe be replaced or extended?
The standard probe uses a fixed 1.2 m cable with 2.5 mm jack termination. Custom-length probes (up to 5 m) are available upon request; extension beyond 3 m may introduce thermal lag and minor resistance-induced error.
Is the display readable in low-light conditions?
No. The LCD is reflective, not backlit. For dark environments (e.g., cold rooms with intermittent lighting), consider mounting near task lighting or pairing with an external LED indicator module.
What is the operating humidity limit for long-term reliability?
Continuous exposure above 95% RH may accelerate sensor hysteresis. For sustained high-humidity applications (>90% RH), desiccant-assisted housing or periodic sensor drying cycles are advised.
Does the alarm function support multiple trigger points?
No. The alarm is single-threshold and configurable for either internal temperature, external temperature, or humidity—selected via mode button. It emits a 1-second audible pulse every 30 seconds until acknowledged.