Variable

Value

Reason

Measurement Instrument/Method used

Wind

1.0 m/s - 1.39 m/s

For minimum heat loss due to free air convection and consistency in test result.

MT130 cup anemometer

Solar Insolation

452 W/m² - 457 W/m²

Minimize variability of results due to thermal inertia.

Mac Solar digital pyranometer

Ambient Temperature

33˚C - 36˚C

For stability and repeatability of results in other regions of the country.

TL8009 mini digital thermometer.

Test time

10:00-14:30 hours (Nigerian Time)

Moderately constant Solar Azimuth angle

$\begin{array}{l}\text{ZenithAngle}\\ =\text{Latitude}-\text{declination}\end{array}$