You don't see arrows going both ways between the target and the sensor? DERP!
It’s a picture. How is that observed? Explain
Yes, the sensor observes the net thermal flux.
They wrote an entire book about the sensors that observe.
Is English your second language?
“Definition:
Net flux represents the amount of substance moved in or out of the cell. It is the mathematical difference between influx and efflux.
Net flux = Influx − Efflux. Similar to influx and efflux,
net flux is reported as a rate.Jan 3, 2014”
I gave my explanation as this relates to.