How to Calibrate Photone
Short explanations to properly calibrate your device, if needed
Do You Need to Calibrate?
We already perform a factory calibration for most devices. However, individual tolerances result in deviations that might or might not be significant for your application. If your measurement does not lie within your expectations, a custom calibration should be performed.
Why Calibration Works
As the deviation generally behaves linearly – meaning it will always be 10% below your expectations, for instance – a calibration to a single reference point is enough to mathematically counteract this shift and our app takes care of the rest.
How To Calibrate
To illustrate the calibration procedure, we've created the following videos showing the required steps for you.
Using a Reference Light Chart
Using a Reference Meter
Using a Reference Device
Ensure Stable Lighting Conditions
Your calibration will be only as good as the lighting conditions when calibrating. If your light intensity fluctuates during the calibration procedure, your calibration will be inaccurate. Therefore, make sure that your lamp is sufficiently warmed-up as it may take a few minutes for the light output to stabilize. You can simply take some control measurements a few minutes apart to make sure that your lamp's output is stable.
What Makes a Good Reference
Your reference should be trustworthy (accurate), stable (precise), and provide readings in either lux, foot-candle, or PAR/PPFD. Good references include high-quality meters, trustworthy light manufacturer measurements, or Photone on another calibrated device. We recommend to use a bright reference as light meters are less accurate when measuring lower light levels.
Please always mind to select the correct unit of measurement within the calibration steps and to keep your setup (distance, lighting, reflections, ...) stable to not alter the results.
Beware of Cheap Light Meters
We tested many different light meters in the mid and low price segment ranging from $20 to $150. As expected, these devices showed a slight deviation of about ±10% from each other when measuring natural light. But when tested under grow lights, we found that the meters deviated with their readings up to ±100%. This means that some meters displayed double (or half) the amount of others in the same environment! For these scenarios it’s best to rely on a light specification or footprint chart.
What About a Diffuser?
Your device may or may not require a diffuser to perform a proper calibration and usage. Our iOS app generally requires a diffuser, while the Android app does not. In any case, the app will tell you on the main screen and within the calibration if a diffuser shall be mounted or not. Please note this information carefully.