New service by UAV / Sewer Savior

Question:
Many workers die when they work in sewer, because they suck in too much poisonous gas, for example, biogas .
Solution:
Make the UAV fly in the sewer.
Dectect the poisonous gas concentration. Using headlamp and surveilance camera to make an inspection tour let workers know the sewer’s circumstance.
Alarm annunciator is designed to use when the poisonous gas concentration approach the numerical value. It’s used to warn the workers exit the sewer quickly.
Make UAV bring signal to prevent from the bad thing happened.