SPECIFICATIONS
Calibration Traceability
Apogee MU series UV-A meters are calibrated through side-by-side comparison to the mean of four transfer
standard UV sensors under UV-enhanced T5 fluorescent tubes. The transfer standard UV sensors are calibrated
through side-by-side comparison to an Apogee model PS-300 spectroradiometer under sunlight (clear sky
conditions) in Logan, Utah. The PS-300 is calibrated with a quartz halogen lamp traceable to the National Institute
of Standards and Technology (NIST).
Spectral Response
MU-250
Calibration Uncertainty
± 10 % (see Calibration Traceability below)
Measurement
Repeatability
Less than 0.5 %
Non-stability
(Long-term Drift)
Less than 2 % per year
Non-linearity
Less than 1 %
Response Time
Less than 1 ms
Field of View
180°
Spectral Range
300 nm to 400 nm (see Spectral Response below)
Directional (Cosine)
Response
± 2 % at 45°, ± 5 % at 75° zenith angle
Maximum Range
104.9 W per m
2
Temperature Response
Less than 0.1 % per C
Operating Environment
0 to 50 C; less than 90 % non-condensing relative humidity up to 30 C; less than 70 % non-
condensing relative humidity from 30 to 50 C
Meter Dimensions
126 mm length; 70 mm width; 24 mm height
Sensor Dimension
30.5 mm diameter, 37 mm height
Mass
180 g
Cable
2 m of two conductor, shielded, twisted-pair wire; TPR jacket (high water resistance, high UV
stability, flexibility in cold conditions)
Spectral response estimate of Apogee
MU series UV-A meters. Spectral
response was modeled from sensitivity
of the photodetector and
transmittance of the diffuser.
