Phase 2 Alerts (Red)
Phase 2 alerts are triggered only after the sensor determines a high probability that the decline in air quality is from a smoldering fire.
After the sensor triggers a Phase 1 alert, the BME688 gas sensor triggers a Phase 2 fire detection process to determine if the observed deterioration in Air Quality is from a smoldering fire or from some other source. If this process determines a high probability that the sensor has detected a smoldering fire, (1) then the sensor sends a Phase 2 alert to the Silvanet Cloud. Otherwise, the sensor needs to reset, which takes from 2-4 hours to complete.
- A smoldering fire is defined to be a slow, flameless combustion of a biomass material such as forest floor material, branches, leaves, and so on.
After a Phase 1 alert is triggered, the sensor needs only 1-2 minutes to determine if a fire is present. It involves 5 steps:
BME688 gas sensor runs gas scans.
Each gas scan is compared to a Fire Model.
High probability of fire triggers a Phase 2 Alert.
Fire Alerts are sent to the Silvanet Cloud.
Fire notifications are sent to registered users.
BME688 sensor runs up to 60 gas scans
After a Phase 1 alert is triggered, the BME688 gas sensor automatically performs up to 60 consecutive gas scans (if necessary) which takes 1-3 minutes to complete. During the gas scan, the sensor measures hydrogen, carbon monoxide and other Volatile Organic Compounds (VOCs).
Each gas scan is compared to a Fire Model
The Silvanet sensor compares each gas scan measurement with pre-trained Machine Learning (ML) Models (Fire Model) (1) to determine if the observed disturbances can be classified as wildfire smoke or from some other source.
- These models have been trained in Dryad's lab to detect typical gas compositions of smoke from burning trees.
High probability of fire triggers a Phase 2 Alert
If the sensor determines that the decline in air quality has a very high probability of being the result of a smoldering fire, gas scans are terminated and the sensor immediately sends a Phase 2 (Red) Alert to the Silvanet Cloud.
If the sensor determines some other source has caused the decline in air quality (diesel fumes or some other similar gasses), then the sensor concludes the gas scans and does not trigger a Phase 2 alert. In this case the sensor must be reset. This can take up to 2 to 4 hours. See Return to normal values after gas scans
Fire Alerts sent immediately to the Silvanet Cloud
A Phase 2 Alert initiates a packet stream where Fire alert data packets are sent via the Mesh Network to the Silvanet Cloud. These packets include the Device ID of the sensor, a timestamp and location.
Fire notifications sent to users
After receiving a Fire Alert, the Silvanet Cloud initiates an email alert notification sent to the registered user's email account. A registered user is a person who has been associated with one or more Sites.
A Fire alert icon also appears in the Site Management app belonging to the user's Dryad account.