LFE Thermal Conductivity Detector (TCD)｜Thermal Conductivity Gas Analysis Technology
The LFE TCD (Thermal Conductivity Detector) is a general-purpose gas analyzer based on the principle of thermal conductivity differences. Its core consists of precision electrically heated filaments and a Wheatstone bridge circuit. When the sample gas flows through and causes a change in thermal conductivity, the filament temperature and resistance change accordingly, allowing the system to rapidly detect variations in gas composition and concentration. It is suitable for process monitoring and safety detection of a wide range of organic and inorganic gases.
Key Features
- Fast response: T90 ≤ 3 seconds (at 60 L/h flow rate)
- High-stability filaments: platinum sensing wires protected with Al₂O₃, glass, and SiOx coatings
- Universal detection: detects nearly all gases with thermal conductivity different from helium or hydrogen
- Corrosion- and high-temperature-resistant gas path: suitable for Cl₂, HCl, H₂S, SO₂, H₂O, and other process gases
- Miniaturized TCD design with fast response and stable signal
- Proprietary technology: enables simultaneous analysis of H₂ / He (not achievable with conventional TCDs)
CONTHOS 3 Series Models
- CONTHOS 3E: 19" rack-mounted, suitable for cabinet integration
- CONTHOS 3F: Standard version, wall-mounted design
- CONTHOS 3F – Ex: Explosion-proof version, compliant with EN 60079 Zone 1 / 2 (Ex p II T4)
- CONTHOS 3F – HT: High-temperature version for extreme process environments
Enclosure and Electrical Specifications
| Model | Dimensions (H × W × D) | Protection Rating | Weight |
|---|---|---|---|
| 3E | 133 × 483 × 427 mm | IP40 | Approx. 10 kg |
| 3F | 434 × 460 × 270 mm | IP65 | Approx. 25 kg |
| 3F – Ex | 490 × 460 × 270 mm | Ex p II T4 (Zone 1 / 2) | Approx. 30 kg |
| 3F – HT | 502 × 460 × 270 mm | IP65 | Approx. 25 kg |
Power supply: 100–240 VAC (48–62 Hz), max. 100 VA during warm-up
Measurement Characteristics
- Measurement principle: differential thermal conductivity (Δλ) TCD
- Ranges: up to 3 switchable ranges (manual / automatic / remote control)
- Minimum range: 0–0.5% H₂ (in N₂)
- Maximum range: 0–100% H₂
- Calibration: manual 2-point (zero/span), optional automatic / remote calibration
- Response time: t90 ≤ 3 seconds
- Accuracy / linearity: ≤ 0.5% of full scale
- Detection limit: ≤ 0.5% of full scale
- Ambient temperature influence: ≤ 1% FS per 10 K change
- Operating temperature: +5 °C to +45 °C