How to Correct for Spectral Errors of Popular Light Sources - Prior to June 1, 2021

Spectral errors can be approximated using wavelength dependent calculations that account for the spectral response of the quantum sensor, the spectral output of calibration light source, and the spectral output of light source being measured. The table below displays the calculated theoretical spectral errors and corresponding correction factors for many different popular lights sources. The spectral errors are calculated relative to each sensor's calibration source (the SQ-110 is calibrated to clear-sky sunlight, the SQ-120 and SQ-500 are calibrated to 4100K cool white fluorescent T5 lamps).

To correct for spectral error multiply your measured value by the correction factor (CF) associated with your light source. For example, if you are using an SQ-120 under a Blue LED (448nm), which has a spectral error of -12.7 and a CF of 1.15, and you measured 115 µmol m^-2 s^-1, you would multiply your measurement of 115 µmol m^-2 s^-1 by the CF 1.15 to get 132.3 µmol m^-2 s^-1 (115 x 1.15 = 132.3).

SQ-110 correction factors apply to sun calibrated models SQ-110, 212, 214, and 215, and models SQ-420, MQ-100, 200, and 210 when in SUN setting.

SQ-120 correction factors apply to electric calibrated models SQ-120, 222, 224, and 225, and models SQ-420, MQ-100, 200, and 210 when in ELEC setting.

SQ-500 correction factors apply to models SQ-500 and 520, and MQ-500, 501, and 510.

This information is also available as an interactive tool, which allows users to upload their own lighting spectrum.