PT100 and PT1000 are the two most popular platinum RTD (Resistance Temperature Detector) sensors used for accurate temperature measurement in industrial, laboratory, and commercial applications. While both are based on the same platinum resistance principle, they have important differences that affect accuracy, installation, and cost. This guide explains the key differences between PT100 and PT1000 sensors to help you make the right choice for your application.
What Are PT100 and PT1000 Sensors?
- PT100: Platinum RTD with 100 ohms resistance at 0°C
- PT1000: Platinum RTD with 1000 ohms resistance at 0°C
- Both follow the IEC 60751 standard and have a temperature coefficient of 0.385%/°C
How Do PT100 and PT1000 Sensors Work?
Both sensors operate on the same principle: the electrical resistance of platinum increases predictably with temperature. A small current is passed through the element, the voltage drop is measured, and resistance is calculated. This resistance is then converted to temperature using standardized calibration curves.
PT100 vs PT1000: Comparison Table
| Feature | PT100 | PT1000 | Which is Better? |
|---|---|---|---|
| Base Resistance (0°C) | 100 Ω | 1000 Ω | PT1000 (higher sensitivity) |
| Temperature Coefficient | 0.385 Ω/°C | 3.85 Ω/°C | PT1000 (10x more sensitive) |
| Lead Resistance Effect | High | Low | PT1000 (better for long cables) |
| 2-Wire Accuracy | ±2-5°C | ±0.5-2°C | PT1000 |
| 3-Wire Accuracy | ±0.3-1°C | ±0.1-0.5°C | PT1000 |
| 4-Wire Accuracy | ±0.1°C or better | ±0.1°C or better | Both |
| Signal Level | Low | High | PT1000 (better SNR) |
| Current Requirement | 1-5mA | 0.1-1mA | PT1000 (lower self-heating) |
| Cost | Lower | Higher | PT100 (more economical) |
| Equipment Compatibility | Widespread | Requires compatible equipment | PT100 (easier integration) |
| Long Cable Runs | Limited | Excellent | PT1000 |
Pros and Cons
PT100 Pros
- Lower cost
- Widespread compatibility
- Industry standard for many years
- Excellent accuracy in 4-wire setups
PT100 Cons
- More affected by lead resistance (especially in 2-wire/3-wire)
- Lower signal levels (more susceptible to noise)
- Not ideal for long cable runs
PT1000 Pros
- Higher sensitivity and signal levels
- Less affected by lead resistance
- Better accuracy in 2-wire/3-wire setups
- Ideal for long cable runs and noisy environments
PT1000 Cons
- Higher cost
- Requires compatible measurement equipment
- Not as widely supported as PT100
Application Scenarios
When to Use PT100
- Short cable runs (<10m)
- Budget-sensitive projects
- Existing PT100-compatible systems
- 4-wire high-accuracy applications
- General industrial and laboratory use
When to Use PT1000
- Long cable runs (>10m, especially >50m)
- 2-wire or 3-wire installations
- Automotive and HVAC systems
- Noisy environments (better SNR)
- When lead resistance is a concern
How to Choose: PT100 or PT1000?
- Check equipment compatibility: Ensure your measurement system supports the chosen sensor type.
- Consider cable length: For long runs, PT1000 is usually better.
- Evaluate accuracy needs: Both can be highly accurate in 4-wire, but PT1000 is better in 2/3-wire.
- Assess budget: PT100 is more economical for most standard uses.
- Think about environment: PT1000 is better for noisy or harsh environments.
Frequently Asked Questions
What is the main difference between PT100 and PT1000 temperature sensors?
The main difference is their base resistance at 0°C: PT100 has 100 ohms, PT1000 has 1000 ohms. PT1000 is more sensitive to temperature changes and less affected by lead resistance, making it better for long cable runs and 2-wire/3-wire setups.
Which is more accurate: PT100 or PT1000?
Both can be highly accurate, but PT1000 generally offers better accuracy in 2-wire and 3-wire configurations due to reduced lead resistance effects. In 4-wire setups, both can achieve similar high accuracy.
When should I use PT1000 instead of PT100?
Use PT1000 for long cable runs, applications where lead resistance is a concern, or when higher signal levels and better noise immunity are needed. PT1000 is also common in automotive and HVAC systems.
Are PT100 and PT1000 sensors interchangeable?
No, they are not directly interchangeable. Their resistance values and signal levels differ, so the measurement equipment must be compatible with the specific sensor type.
Which is more cost-effective: PT100 or PT1000?
PT100 sensors are generally less expensive and compatible with a wider range of equipment. PT1000 sensors may have higher initial costs but can offer better performance in certain applications.
Conclusion
PT100 and PT1000 temperature sensors are both excellent choices for accurate and reliable temperature measurement. The best choice depends on your application's requirements for cable length, accuracy, equipment compatibility, and budget. PT1000 is ideal for long cable runs, noisy environments, and when lead resistance is a concern, while PT100 remains a cost-effective, industry-standard solution for many applications.