The DHT11 sensor is a basic temperature and humidity sensor, but its accuracy is relatively low compared to more advanced sensors like the DHT22 (AM2302) or SHT3x series.
📊 DHT11 Accuracy Specifications:
- Temperature Accuracy: ±2°C
- Humidity Accuracy: ±5% RH
- Temperature Range: 0°C to 50°C
- Humidity Range: 20% to 90% RH
- Sampling Rate: 1 reading per second (1Hz)
🔍 Why is DHT11’s Accuracy Limited?
1️⃣ Lower Resolution – It provides integer values (no decimals) for temperature.
2️⃣ Limited Humidity Range – Doesn’t measure below 20% RH, making it unreliable in dry conditions.
3️⃣ Plastic Casing – Slows down response time and affects precision.
✅ When is DHT11 Good Enough?
- If you need basic environmental monitoring (e.g., room conditions).
- If ±2°C accuracy is acceptable for your project.
- If you’re okay with a low refresh rate (1Hz).
❌ When to Use a Better Sensor?
- If you need higher accuracy (DHT22: ±0.5°C, ±2% RH).
- If you’re working with extreme temperatures (DHT22: -40°C to 80°C).
- If you want faster updates (e.g., SHT31, BME280).
🚀 Alternatives with Better Accuracy:
| Sensor | Temperature Accuracy | Humidity Accuracy | Range (°C) | Range (RH) | Sampling Rate |
|---|---|---|---|---|---|
| DHT11 | ±2°C | ±5% RH | 0 to 50°C | 20-90% RH | 1 Hz |
| DHT22 (AM2302) | ±0.5°C | ±2% RH | -40 to 80°C | 0-100% RH | 0.5 Hz |
| SHT31 | ±0.3°C | ±2% RH | -40 to 125°C | 0-100% RH | 10 Hz |
| BME280 | ±1°C | ±3% RH | -40 to 85°C | 0-100% RH | 1-100 Hz |
Verdict:
DHT11 is okay for simple projects but not for precision applications. If you need better accuracy, go for DHT22, SHT31, or BME280. 🚀
