What measurements are affected by this issue?
Not affected: Typical Broadband Lights.
Spectral errors were less than 2 % from broadband radiation sources, including sunlight, cool white fluorescent, metal halide, high pressure sodium, white LED fixtures, blue/red LED fixtures, and all other LEDs with peaks greater than 450 nm. No further action is required to update your current sensor/meter.
Partially affected: Deep-water measurements.
For users making deep-water measurements outdoors, errors from sunlight attenuation increases with depth, with an estimate of 4 % error occurring at 10 m. Please see the white paper for detailed error multipliers you can use to correct your data, or you can contact Apogee to have your sensor updated at no cost.
Affected: Deep Blue and Violet Lamps.
For users measuring lighting fixtures with a high percentage of output between 400 and 420 nm (for example, fixtures with only Actinic or Blue Plus T5 bulbs), measurements were 10 to 20 % low. Lighting fixtures containing only these bulbs are rarely used, as they are usually mixed with broader spectrum bulbs, like standard T5 bulbs. When Actinic and Blue Plus bulbs are mixed with broader spectrum bulbs, measurement errors are reduced to less than 5 % and may not be considered significant to many users (see accompanying white paper for mixed fixture errors and correction multipliers). If you are measuring fixtures with bulbs that only output in the deep blue/violet range, you can either use the correction multipliers provided in the white paper to correct your data, or contact Apogee to have your sensor updated at no cost.
If you have any questions about this announcement, please contact Apogee Instruments Technical Support department at firstname.lastname@example.org or (435)792-4700.
Serial Number Ranges:
MQ-500 S/N 1001-1457
MQ-510 S/N 1001-1109
SQ-500 S/N 1001-1227
SQ-520 S/N 1001-1359
SQ-514 S/N 1001-1002
To learn more about this issue, please click here to read a whitepaper created by Apogee’s engineers.