Specifications

TEAM Climate Monitoring Protocol 3.0

Figure 11. Diagram showing the correct way to connect the power cable terminals to the data logger.

5.5.2 Licor200X Solar radiation sensor

It is recommended to install two pyranometers for redundancy and to account for seasonal

changes in solar path. If the pyranometer is not at the very top of the base tower, the base tower

could shade it during some periods of the year depending on the geographical location of the

field station. For example, in stations located north of the equator the sun path moves southwards

between the summer solstice (June 21) and the winter solstice (December 21) and then back

northwards until the next summer solstice (June 21). If the pyranometer is facing south then the

tower may cast a shade on it between the summer solstice and the fall equinox (September 23)

and then again between the spring equinox (March 21) and the summer solstice (see

http://astro.unl.edu/naap/motion3/animations/sunmotions.swf for a nice simulation of this). A

similar situation can arise for tropical locations south of the equator. To avoid this problem it is

better to have two pyranometers, one facing north and one facing south and then the appropriate

reading can be post-processed depending on the time of the year (not in the original data!). Even

if the pyranometer is not shaded (e.g. at the top of a structure), it is always better to have two in

case one gets dirty, or malfunctions.

Mounting the sensor: Attach a cross-arm stand to the end of the cross arm to provide a leveled

surface for the sensor (Figure 12). The height of the sensor is not as critical as the orientation

(either facing north or south). Mount the sensor on the leveling base (LI2003S) to ensure it is

adequately leveled. The base has a bubble level and adjustment screws to level the sensor

accurately.

Secure and connect the cables: Once the sensor is mounted and leveled, route and secure the

cable along the cross arm and then along the tower and into the enclosure. Finally, connect the

ends of the cables to the appropriate terminals as shown in the wiring diagram that comes with

the data collection program. REMOVE THE RED CAP AFTER INSTALLING THE

PYRANOMETER (save for future storage/shipping).

Figure 12. Diagram showing the mounting configuration for the LI200X pyranometer (adapted from

Campbell 2008).