ESP32 Ait Qualuty Sensor

### Air Quality Index
| AQI Level | Description       | Suggestion                                          | Recommended Stay Time         |
|-----------|-------------------|----------------------------------------------------|-------------------------------|
| 5         | Extremely bad     | In unavoidable circumstances, please strengthen ventilation | Not recommended to stay       |
| 4         | Bad               | Strengthen ventilation, find sources of pollution | Less than one month           |
| 3         | Generally         | Strengthen ventilation, close to the water source | Less than 12 months           |
| 2         | Good              | Maintain adequate ventilation                      | Suitable for long-term living |
| 1         | Excellent         | No suggestion                                     | Suitable for long-term living |

### eCO2/CO2 Concentration Reference
| eCO2/CO2 Level | Description  | Suggestion                                      |
|-----------------|-------------|------------------------------------------------|
| 21500          | Terrible     | Indoor air pollution is serious and requires ventilation |
| 1000-1500      | Bad          | Indoor air is polluted, ventilation is recommended       |
| 800-1000       | Generally    | Can be ventilated                              |
| 600-800        | Good         | Keep it normal                                |
| 400-600        | Excellent    | No suggestion                                 |

### TVOC Concentration Reference
| TVOC (ppb) | Effects on Human Health              |
|------------|--------------------------------------|
| >6000      | Headaches and nerve problem          |
| 750-6000   | Restless and headache                |
| 50-750     | Restless and uncomfortable           |
| <50        | No effect                            |