Timepower TP208 Precision Chilled-Mirror Hygrometer for SF₆ and Inert Gases
| Brand | Timepower |
|---|---|
| Origin | Beijing, China |
| Manufacturer Type | OEM Manufacturer |
| Country of Origin | China |
| Model | TP208 |
| Pricing | Upon Request |
Overview
The Timepower TP208 Precision Chilled-Mirror Hygrometer is a laboratory-grade dew point analyzer engineered for trace moisture measurement in technically demanding industrial and calibration environments. It operates on the fundamental physical principle of chilled-mirror condensation hygrometry: when a gas stream is cooled across a highly polished, temperature-controlled optical mirror surface, water vapor reaches saturation and forms a visible dew layer at the thermodynamic dew point temperature. This primary measurement method—defined in ISO 8503-1, ASTM E104, and IEC 60068-2-30—is recognized as the reference standard for humidity metrology due to its direct traceability to thermodynamic equilibrium and absence of chemical or polymer-based sensor drift. The TP208 is specifically validated for high-accuracy dew point determination in sulfur hexafluoride (SF₆), nitrogen (N₂), argon (Ar), helium (He), and other non-condensable, non-reactive gases commonly used in high-voltage switchgear, semiconductor purge lines, and inert atmosphere gloveboxes.
Key Features
- Chilled-mirror optical detection system with real-time photometric feedback for unambiguous dew layer identification and suppression of false condensation events.
- Four-stage Peltier thermoelectric cooling architecture enabling stable mirror temperature control down to –60 °C at ambient 10 °C, with thermal stability ≤ ±0.02 °C over 10-minute intervals.
- Digital fuzzy logic temperature control algorithm minimizing thermal overshoot and reducing equilibration time to 3–5 minutes under nominal flow conditions.
- Corrosion-resistant wetted path constructed from electropolished stainless steel and PTFE-sealed fittings, compatible with SF₆, H₂S, Cl₂, and other moderately aggressive process gases.
- High-resolution 4.3-inch color TFT LCD display showing simultaneous dew point (°C), volumetric moisture concentration (µL/L), real-time mirror temperature curve, mass flow rate (L/h), and diagnostic status flags.
- Integrated self-diagnostics including optical energy monitoring (displayed as % reflectance), flow validation alerting, dew detection confidence scoring, and thermal gradient anomaly detection.
- Passive air-cooled heat dissipation design ensuring silent operation and compact footprint (320 × 300 × 190 mm; 6.6 kg) suitable for benchtop deployment in QC labs and field service carts.
Sample Compatibility & Compliance
The TP208 is certified for use with dry, non-particulate, non-oily gas streams having dew points between 0 °C and –60 °C (at 10 °C ambient). It complies with IEC 61000-4 electromagnetic immunity standards and meets mechanical safety requirements per IEC 61010-1 for measurement equipment. Its measurement protocol supports traceability to national metrology institutes (NMIs) via NIST-traceable chilled-mirror reference standards. For regulated industries—including power transmission (IEC 60480, IEEE C37.122.1), pharmaceutical inerting (USP ), and aerospace purge validation—the instrument’s deterministic physics-based output satisfies GLP/GMP data integrity expectations without requiring periodic sensor recalibration.
Software & Data Management
While the TP208 operates as a standalone instrument with full local control, optional RS-232/USB interfaces enable integration into centralized SCADA or LIMS platforms. All displayed parameters—including timestamped dew point, flow rate, optical energy, and alarm logs—are exportable in CSV format. The device supports audit trail functionality through user-accessible event logging (e.g., “Flow out of range”, “Mirror contamination warning”), aligning with FDA 21 CFR Part 11 principles for electronic records where configured with external authentication layers.
Applications
- Moisture verification of SF₆ insulating gas in GIS/GIL systems prior to commissioning and during routine maintenance (per IEC 60480 Annex B).
- Residual moisture monitoring in nitrogen-purged transformer oil processing and cable splicing enclosures.
- Quality control of ultra-high-purity (UHP) carrier gases in semiconductor diffusion furnaces and CVD tools.
- Calibration transfer between primary chilled-mirror standards and secondary aluminum oxide or quartz crystal sensors.
- Environmental testing chamber humidity validation where low-ppb-level dryness must be confirmed.
FAQ
What pre-conditioning steps are required before measurement?
Prior to analysis, flush the sample line and optical chamber with ≥99.999% pure nitrogen at 30 L/h for ≥15 minutes to remove adsorbed moisture and stabilize optical reflectance.
How is optical performance monitored during operation?
The instrument continuously measures mirror reflectance intensity and displays it as a percentage (target range: 99–100%). A value below 99% indicates potential mirror contamination or misalignment requiring cleaning or service.
Can the TP208 measure gases under pressure?
Yes—it accepts inlet pressures from 10 mbar to 10 bar (1 kPa to 1 MPa); however, internal pressure regulation is not provided, so external pressure-reducing valves must be installed upstream for overpressure protection.
Is the dew point reading automatically compensated for pressure?
No—the TP208 reports true mirror-surface dew point temperature. Users must apply appropriate pressure correction algorithms (e.g., Magnus formula variants) if reporting ppmv or g/m³ at non-atmospheric conditions.
