Rotronic HC2-S3 Precision Temperature and Humidity Sensor

Overview

The Rotronic HC2-S3 is a high-stability, laboratory-grade temperature and humidity sensor engineered for traceable environmental monitoring in regulated and research-critical applications. It operates on the principle of dual-sensor metrology: a platinum resistance thermometer (Pt100 RTD) conforming to IEC 60751 Class B (1/3 tolerance) for temperature measurement, and a capacitive polymer humidity sensing element with integrated temperature compensation. Unlike its predecessor—the HYGROClip S3—the HC2-S3 features a robust stainless-steel MIL-C-5015 aviation connector, eliminating mechanical vulnerability associated with legacy plastic housings and ensuring long-term signal integrity under vibration, thermal cycling, and repeated mating cycles. Its design supports continuous operation across an extended environmental envelope (−50 to +100 °C; 0–100 % RH), while maintaining metrological performance within tightly defined uncertainty budgets—making it suitable for use in stability chambers, cleanrooms, climatic test cabinets, and reference-grade validation systems.

Key Features

• Stainless-steel MIL-C-5015 aviation connector for enhanced mechanical durability, EMI shielding, and repeatable electrical contact—critical for GxP-compliant installations.
• Pt100 RTD sensor with IEC 60751 1/3 Class B tolerance (±0.06 K at 0 °C), enabling high-resolution temperature measurement from −40 to +60 °C with ±0.1 K accuracy at 23 °C.
• Capacitive humidity sensing element calibrated at up to nine RH points (10–90 % RH in 10 % increments), delivering ±0.5 % RH accuracy under ISO/IEC 17025-aligned calibration conditions.
• Analog 0–1 VDC output with low-noise signal conditioning, compatible with data loggers, PLCs, SCADA systems, and custom DAQ hardware supporting ratiometric or precision voltage input channels.
• Wide supply voltage range (3.2–5 VDC or 12 VDC), supporting both low-power embedded deployments and industrial control environments without external regulation.
• Extended operational envelope (−50 to +100 °C ambient; 0–100 % RH) with condensation-tolerant housing design—enabling reliable use in dynamic humidity ramp tests and sub-zero storage validation.

Sample Compatibility & Compliance

The HC2-S3 is not a sample-contact instrument but a direct-reading environmental probe—designed for installation in air streams, enclosures, ducts, and controlled atmospheres where representative ambient condition capture is required. Its stainless-steel body and hermetically sealed sensing chamber meet IP65-rated ingress protection when properly mounted. The sensor complies with electromagnetic compatibility requirements per EN 61326-1 (industrial environment), and its calibration traceability aligns with ISO/IEC 17025 when performed by an accredited laboratory. While not intrinsically safe, it is suitable for non-hazardous area deployment in accordance with IEC 60079-0. For regulatory validation workflows—including those governed by FDA 21 CFR Part 11, EU Annex 11, and WHO TRS 961—the HC2-S3 supports documented calibration intervals, as-found/as-left records, and uncertainty budget reporting when integrated into validated monitoring systems.

Software & Data Management

The HC2-S3 operates as a standalone analog transducer and does not embed firmware or require proprietary drivers. However, it integrates seamlessly with Rotronic’s HygroLog NT software suite (via compatible Rotronic MP100/MP150 data loggers) for automated calibration certificate generation, trend analysis, alarm threshold configuration, and electronic audit trail creation. When used with compliant data acquisition platforms, the sensor supports full ALCOA+ data integrity principles: attributable, legible, contemporaneous, original, and accurate. Its 0–1 VDC output enables straightforward scaling in LabVIEW, Python (with NI-DAQmx or similar), MATLAB, or commercial SCADA systems—facilitating custom interpolation, real-time dew point calculation, and uncertainty propagation modeling per GUM (JCGM 100:2018).

Applications

• Environmental qualification of pharmaceutical stability chambers (ICH Q1, USP <1151>) and cold chain logistics monitoring.
• Validation of HVAC performance in ISO 14644-classified cleanrooms and aseptic processing suites.
• Reference-grade humidity calibration transfer between primary standards (e.g., chilled mirror hygrometers) and working standards.
• Long-term climate monitoring in museum conservation, archival storage, and materials aging studies.
• Embedded use in OEM environmental test equipment requiring NIST-traceable, low-drift sensing with field-replaceable probe architecture.

FAQ

Is the HC2-S3 suitable for use in saturated or condensing environments?
Yes—the sensing head incorporates hydrophobic filtration and condensation management geometry, enabling stable operation up to 100 % RH at temperatures ≥0 °C. Prolonged exposure below 0 °C with high RH requires careful assessment of frost formation on the filter membrane.

Does the HC2-S3 require periodic recalibration?
Per ISO/IEC 17025 and industry best practice, annual calibration is recommended for GxP applications. Rotronic provides factory calibration certificates with measurement uncertainty statements and optional on-site verification services.

Can the HC2-S3 be used with third-party data loggers?
Yes—its 0–1 VDC analog output is fully compatible with any data acquisition system supporting high-impedance voltage inputs and configurable scaling (e.g., 0 V = −40 °C / 0 % RH; 1 V = +60 °C / 100 % RH).

What is the typical measurement response time (τ63%) for temperature and humidity?
At 1 m/s airflow, typical τ63% is ≤15 s for temperature and ≤25 s for humidity—values confirmed per ISO 11784 and Rotronic’s internal characterization protocol.

Is the stainless-steel connector rated for washdown or autoclave use?
No—the connector is corrosion-resistant and mechanically rugged but not designed for direct chemical exposure, steam sterilization, or repeated high-pressure cleaning. For such applications, consult Rotronic’s HC2-AW or HC2-IC series variants.