My grow hub has been up and running my tent for about a week and I’m very impressed so far in its ability to chase vpd. When I did the original setup I calibrated the light to 100% and it worked great recognizing when I dimmed it. It dropped to 56% yesterday while i was at work so I recalibrated the sensor again last night. I know my light is at 100% but the app shows 60% today. The sensor hangs 4" above the canopy pretty much in the center of the tent. Is there something I’m missing or should I just ignore it on the app?
Hello @Dmr7547 some context first. LEDs are “not dimmable” like a regular filament bulb, controlling the current signal waveform. They are usually controlled with a PWM signal and instead of being precisely adjusted in the amount of lux they provide they are just switched on and off quickly (in milliseconds) based on an input signal, usually 0-10V, so there is not a precise relation between how much you tune the dial and an exact amount of lux, it can be 500lux now, 0 lux 50 milliseconds after as they are switching from “full ON” to “full OFF”
Because the LEDs are switching on and off for a certain amount of time (milliseconds) while they are dimmed the Niwa LED may not be accurate on the readings, because the sensor takes readings every certain amount of time and average those readings.
In essence, the Niwa Grow Hub is not an accurate way to read the output of your LEDs in a precise way, it’s just a relative measure (%) that will help you to determine a LED blown, for example. I’d recommend other sensors, for example, a PAR sensor, for that goal, it will also provide much more useful information as the spectrum of your LEDs.
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