The DHT11 sensor has a listed accuracy of:
- Β±2Β°C for temperature
- Β±5% for humidity
This means that any reading you collect can vary within this range, affecting the reliability of your data. Letβs break down how this impacts real-world applications. π
β‘ 1. Temperature Accuracy (Β±2Β°C)
πΉ What It Means?
If the DHT11 reports 25Β°C, the actual temperature could be anywhere between:
23Β°C to 27Β°C
This 2-degree margin of error may not seem like much, but for precise applications, it can be a problem.
πΉ How It Affects Different Applications?
β
General Room Monitoring: No big deal; a 2Β°C difference wonβt impact comfort.
β Precision Climate Control (e.g., Incubators, Labs): Too inaccurate! 2Β°C could be critical.
β Weather Monitoring: May not be reliable for scientific purposes.
πΉ How to Reduce Errors?
- Use an average of multiple readings to smooth out variations.
- Calibrate the sensor against a more accurate thermometer.
- Use a higher-accuracy sensor like DHT22 (Β±0.5Β°C) or BME280 (Β±0.25Β°C).
π§ 2. Humidity Accuracy (Β±5%)
πΉ What It Means?
If the DHT11 reports 50% humidity, the actual value could be anywhere between:
45% to 55%
For applications requiring precise humidity control, this is a significant margin of error!
πΉ How It Affects Different Applications?
β
General Home Monitoring: Fine for basic indoor humidity tracking.
β Greenhouses & Mushroom Farming: Small changes in humidity matter.
β Industrial Applications (e.g., Server Rooms, Pharmaceuticals): Requires better accuracy.
πΉ How to Reduce Errors?
- Use averaging to stabilize fluctuating values.
- Place the sensor away from heat sources or drafts.
- Upgrade to a DHT22 (Β±2% humidity) or SHT31 (Β±1.8%).
π 3. Real-World Impact of DHT11 Accuracy
Application | Effect of Β±2Β°C & Β±5%RH Error | Recommended Sensor? |
---|---|---|
Home Monitoring | Minimal impact | DHT11 is fine β |
DIY Weather Station | Moderate impact | Upgrade to DHT22 π |
Greenhouse Control | Can affect plant health | Use BME280 π± |
Industrial Climate Control | Not suitable | Use SHT31 or SI7021 π |
Incubators & Labs | Critical errors possible | Use DHT22 or higher π‘ |
π Conclusion β Is DHT11 Good Enough?
β
DHT11 is OK for basic hobby projects like home monitoring and DIY weather stations.
β For precision applications, itβs not reliable enough β upgrading to DHT22, BME280, or SHT31 is better.