Resistance Temperature Detectors (RTDs) are temperature sensors that operate based on the principle of electrical resistance variation in metals with temperature changes. Platinum is the most commonly used material due to its stability and linear resistance-temperature relationship. RTDs provide precise and repeatable temperature measurements, making them critical in industrial process control, scientific research, and quality assurance systems.
| Type | Functional Characteristics | Application Examples |
|---|---|---|
| Platinum RTD (Pt100/Pt1000) | High accuracy ( 0.1 C), wide temperature range (-200 C to 850 C) | Industrial process control, HVAC systems |
| Copper RTD | Lower cost, limited range (-50 C to 150 C) | Motors temperature monitoring |
| Nickel RTD | High sensitivity but non-linear output | Aerospace applications |
| Thin-Film RTD | Compact size, fast response time | Medical devices, semiconductor manufacturing |
| Wire-Wound RTD | High vibration resistance, mechanical durability | Power generation plants |
Typical RTD construction includes:
| Parameter | Significance | Typical Values |
|---|---|---|
| Temperature Range | Determines operational limits | -200 C to 850 C (Pt100) |
| Accuracy Class | Defines measurement precision | Class A ( 0.15 C), Class B ( 0.3 C) |
| Response Time | Critical for dynamic temperature tracking | 0.5-20 seconds |
| Electrical Resistance | Affects signal transmission quality | 100 (Pt100), 1000 (Pt1000) |
| Self-Heating Error | Impact of excitation current on measurement | <0.02 C/mW |
| Manufacturer | Representative Product | Key Features |
|---|---|---|
| Honeywell | TD Series | IP67 rating, -50 C to 250 C range |
| Omega Engineering | PX Series | Explosion-proof design, Class A accuracy |
| Yokogawa | YTA Series | HART protocol support, 4-wire configuration |
| ABB | MT Series | Digital signal processing, SIL2 compliance |
Key considerations:
Emerging developments include: