6. Irradiation Intensity Control
The system irradiation intensity was set to an average 1000W/m
2
(+/-15%; class C
uniformity) at the time of installation. This intensity distribution test is included in Section 3 of
this manual. We recommend that the irradiation intensity is verified approximately every 500
hours of operation or once per month. To adjust the irradiation intensity, please follow the
steps below.
a) Refer to initial installation irradiation intensity distribution diagram included in Section
3 of this manual.
b) Select at least two (2) distributed test locations from distribution grid (these positions
are marked by tape on the bottom of the chamber roller shelf).
c) Turn on full solar array and allow at least ten (10) minutes for the lamps to stabilize.
d) Place a full spectrum pyranometer on the first of these selected positions and
measure irradiation intensity, then repeat at the second selected position.
e) Compare these measurements against the initial installation irradiation intensity
measurements, if the difference is more than five (5) percent it is recommended that
a full 18 point irradiation intensity grid measurement is performed. This will provide
the minimum irradiation intensity point and allow the calculation of the average
irradiation intensity and full target uniformity.
f) If the minimum irradiation intensity is below 850W/m
2
the irradiation intensity power
should be adjusted using the DIMMING CONTROL calibrated dial. This circuit
outputs a 0-10V signal that controls the power output (0V = Max power; 10V = Min
power). A typical value for a new installation (set to 1000W/m
2
) will be approximately
4.2V.
g) Place the pyranometer at the minimum measured irradiation intensity grid point and
ensure the reading is stable. Adjust the controller voltage lower while reading the
intensity level from the pyranometer (allow sufficient time after any adjustment for
the intensity level to stabilize).
h) Adjust the power such that the intensity level is increased to a value between 900-
950W/m
2
.
i) Re-measure the full 18 point grid irradiation intensity and re-calculate the Max, Min,
and Average values to ensure they are within specification.
If, for a particular application, you desire to reduce the average irradiation intensity to a value
lower than 1000W/m2 (such as 850W/m2), please follow steps g) – i) above and adjust the
power output proportionally to the desired average irradiation intensity level.
NOTE: To ensure solar lamp irradiation and spectrum stability, the average irradiation
intensity (power output) should not be reduced below 800W/m
2
.
