Field Notes

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Other sites visited today: Sherman Wetland
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Tonzi: 2017-09-28 10:30:00 (DOY 271)
Author: Joe Verfaillie
Others: Daphne

Summary: Rewire and upgrade Tower solar system, tried to calibrate soil co2 Vaisala, new CO2 and N2 tanks for tower profile that is not running yet.

Tonzi
2017-09-28

Daphne and I arrived at about 10:30. It was hot, dry and clear with little to no wind. The trees that didnâ€™t turn entirely brown have lost what brown leaves they had so the trees are looking a bit greener. Some kind of large tractor with caterpillar treads has recently gone along the road and to the south of the road in places.

The task for the day was to upgrade the Towerâ€™s solar power system. Daphne rewired the solar panels in to three strings of four panels in series. The three strings run vertically so the panels to the east are one string the ones in the middle are a second and the panels to the west are the third. The black (negative) wires are spliced with wire nuts and the red wires connect the panels in series. This produces about 4A at 80VDC. The three sets are connected in parallel along the bottom of the panels with the #6 gauge wire. We had to manufacture some wire clamps to splice two #6 and one #10 wire in two places.

At the charge controller box at the base of the tower, I pulled out the two charge controllers sn SCC-001 and sn 0135002X. I installed a wooden backplane and a Midnite Kid MPPT controller sn KB04594 with a 20A breaker for the 16A solar input and a 5A breaker for the 24V load. The line to the battery bank has a 30A fuse in it right now but should be replaced by a breaker that I need to buy. I also removed a relay that looked like it used to be used to cycle all the power on the tower controlled by the 23x at the top. I didnâ€™t have four mounting screws for the charge controller â€“ I tied it in temporarily with some wire. I also need screws for the 24V terminal strip. The charge controller seems to have been set up for a 12V system and I couldnâ€™t find a way to change it completely, but I was able to adjust the absorb and float voltages to 28V and 26V.

I rewired the battery bank into six pairs for a 24V system. The wires to the charge controller are a little short. I removed some flexible aluminum conduit to get some extra length. I disconnected the ground wire in the process and forgot to reconnect it.

We installed DC-DC converters, one in the solar charge controller box and one in the tower top 23x box to step down from 24V to 12V for the data loggers. We checked that the Floor 23x, Tower top 23x, zcam 10x and Licor GHG systems were running before we left. The Licor GHG system is running on 24V. I reset the zcam 10x clock by about 10min.

We brought brand new tanks of N2 and CO2 for the profile system but did not get the system set up. The tanks are in place but need their regulators checked.

I also tried to calibrate the soil CO2 Vaisala in situ. I brought the box with an Eosense probe on a CR6 to the field. I uploaded a new program to the soil CO2 23x to collect data every 10sec. I put the four Vaisala at each location in the box and used my breath to bring the concentration up to about 1%. The idea was to watch the concentration decrease as the CO2 leaked out. However the 23x stopped logging data after 10 mins or so. I uploaded the original program before leaving.

Field Data

No tank data

No TZ Well data found

No TZ Moisture Point data found

No VR Moisture Point data found

No TZ grass heigth found

No VR grass heigth found

No TZ Tree DBH found

No water potential data found

No TZ Grass Biomass data found

No TZ OakLeaves Biomass data found

No TZ PineNeedles Biomass data found