ChemTron THI 350 Thermo-Hygrometer

Overview

The ChemTron THI 350 Thermo-Hygrometer is a precision-engineered handheld instrument designed for simultaneous, non-contact surface temperature and ambient relative humidity measurement in industrial process monitoring, HVAC commissioning, laboratory environmental validation, and material conditioning applications. Unlike conventional hygrometers limited to air-based readings, the THI 350 integrates dual-sensing architecture: an infrared pyrometer for emissivity-compensated surface temperature assessment (−60 °C to +500 °C), and a high-stability capacitive humidity sensor for ambient RH determination (1–99 % RH). Its 12:1 optical distance-to-spot ratio enables reliable targeting of small or thermally isolated surfaces—such as piping insulation, drying ovens, pharmaceutical packaging trays, or composite curing molds—without physical contact. The device operates on a robust, low-power platform optimized for field use and complies with IEC 60584-1 for thermocouple reference tables and ISO 7726 for thermal environment instrumentation classification.

Key Features

• Triple-probe compatibility: Supports fixed capacitive (TFH 610), flexible-cable capacitive (TFH 620), and integrated IR+RH (THI 350) configurations for application-specific deployment.
• Emissivity-adjustable infrared optics (0.1–1.0) with factory-default 0.95 setting, enabling accurate surface temperature measurement across diverse materials—including painted steel, anodized aluminum, polymer films, and cured concrete.
• High-speed thermal response: <1 second rise time ensures dynamic process tracking during rapid thermal transients, such as steam sterilization cycles or exothermic reaction monitoring.
• Traceable factory calibration: Supplied with a documented certificate conforming to ISO/IEC 17025 requirements, including uncertainty budgets for both temperature and humidity channels.
• Industrial-grade ergonomics: IP54-rated enclosure (dust-protected, splash-resistant), compact form factor (46 × 143 × 184.8 mm), and battery-operated design support extended field deployment without external power.

Sample Compatibility & Compliance

The THI 350 is validated for use with non-corrosive, non-condensing environments where ambient temperatures remain between 0 °C and 50 °C. It meets EN 61326-1:2013 for electromagnetic compatibility in industrial settings and conforms to RoHS 2011/65/EU and REACH (EC) No. 1907/2006 regulatory frameworks. While not intended for intrinsically safe zones, its low-energy operation (<100 mW active draw) minimizes spark risk in standard industrial atmospheres. For GxP-regulated environments—including pharmaceutical cleanrooms and medical device manufacturing—the device supports audit-ready documentation when paired with optional calibration management software (e.g., ChemTron CalTrack Suite v3.2), enabling full traceability per FDA 21 CFR Part 11 requirements for electronic records and signatures.

Software & Data Management

Data logging and configuration are managed via ChemTron’s PC-based CalTrack Desktop Utility (Windows 10/11 compatible), which allows users to export timestamped measurement series in CSV or Excel-compatible formats. The utility supports batch calibration report generation, emissivity profile assignment per material class, and user-defined alarm thresholds for out-of-specification RH or surface temperature excursions. All firmware updates are digitally signed and delivered through ChemTron’s secure customer portal, ensuring integrity and version control. Audit trails—including operator ID, calibration date, and parameter modification history—are retained locally on-device memory and synchronized upon USB connection.

Applications

• Pharmaceutical lyophilization chamber mapping and shelf temperature uniformity verification.
• HVAC ductwork surface condensation risk assessment using dew point differential analysis.
• Composite material layup monitoring during autoclave curing, where surface emissivity shifts must be compensated in real time.
• Food processing line validation—measuring ambient RH near packaging stations and surface temp of stainless-steel conveyors.
• Electronics assembly floor environmental qualification per IPC-STD-168 for moisture-sensitive devices (MSD).

FAQ

Does the THI 350 require periodic recalibration?
Yes. ChemTron recommends annual recalibration against NIST-traceable standards; intervals may be shortened based on usage frequency, exposure to condensation, or mechanical shock.
Can the THI 350 measure humidity inside sealed enclosures?
No—it measures ambient RH at the instrument’s location. For internal enclosure monitoring, use the TFH 620 probe with extended cable routed through a sealed feedthrough.
Is emissivity correction mandatory for accurate surface temperature readings?
Yes. Uncompensated emissivity leads to systematic error; the THI 350 requires manual input of material-specific emissivity values prior to IR measurement.
What is the minimum measurable spot size at 1 meter distance?
With a 12:1 D:S ratio, the minimum spot diameter is approximately 83 mm at 1 m distance.
Does the device support data export to LIMS or MES platforms?
Yes—via CalTrack Desktop’s configurable ODBC driver or direct CSV output compatible with LabWare LIMS, Siemens Opcenter, and similar enterprise systems.