Custom Calibrations allow you to adjust or offset parameter values to better reflect your current environmental conditions. You can simply offset any parameter value by a flat amount or apply a more sophisticated polynomial formula to create a best fit to your reference device.
For example to increase the humidity value by 5%, simply go to the device calibration page, click on 'Add Custom Calibration', select Humidity, and then enter the (5,1) in 'Calibration Params' field.
If you hit the test button, you'll able to input a sample value, x, and see output value, f(x) given the function you've constructed. Here we see that when the raw data or underlying value is 65%, the custom calibration will cause it show 70% instead.
The Calibration Params input accepts a string of numbers separated by a comma to represent polynomial coefficients as follows:
Calibration Params: (a, b, c, d)
f(x) = a + b*x + c*x^2 + d*x^3 ...
Therefore (5,1) creates f(x) = 5 + 1*x. At least two values are required (a,b) and you can use negative numbers to adjust values lower instead.
Note: Custom Calibration only apply to the current device configuration and do not persist through resets. They will be removed once a device is reset and a new initial configuration created.