Field Notes

<--2018-02-28 11:40:00 | 2018-03-19 08:30:00-->
Other sites visited today: West Pond
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Twitchell Alfalfa: 2018-03-07 09:45:00 (DOY 66)
Author: Daphne Szutu
Others: Joe

Summary: Switched power system from 24V to 12V, removed Eosense/Forerunner CO2 probes, added LI-6400 power cable, updated stardot file names

2018-03-07
Twitchell Alfalfa

Joe and I arrived at 9:45. It was overcast and cool. The field is mostly grass and nettles, with a few alfalfa here and there. There were many geese on the field south of us and huge flocks on the pastures near the east edge of the island.

I collected met, camera, USB, and soil CO2 data. The 7500 read: 461ppm CO2, 434mmol/m3 H2O, 12C, 101.9kPa, 103SS. I renamed the stardot file names from twitchellalfalfa to twitchellalfalfa2 to match the upload protocol at Phenocam Network.

We re-wired the power system from 24V to 12V. This allows us to easily add single solar panels or batteries in the future. The system had had been at 24V to support the old Vaisala CO2 probes. The current Vaisala can run on 12V, there are no long power runs in the system, and being at 12V will allow us to remove a bunch of power converters. We re-wired the met box and swapped the power converter for the network switch (12V to 5V), as the old power converter seemed to only work on 24V. The battery bank sn BB-TA was rewired from two pairs to four in parallel but we were short two battery cables. We use some 14 gauge wire temporarily. The barely long enough power cable between the batteries and the solar charge controller was replaced with a longer one.

The solar panels were rewired from series at parallel. The wire between the two panels was replaced due to lots of squirrel chew and still needs slit loom.

I re-wired the soil CO2 box for 12V, configured Vaisala boards for 12V operation (moved red wire from Hi to Lo), and removed eosense/Forerunner CO2 probes: sn GP20140084 was at -2cm, sn GP20140026 was at -8cm, sn GP2013ex02 was at -16cm. The 12V screw terminal has the datalogger, FD chamber, and LI-6400. The SW12V bus is connected to Vaisala CO2 and VWC theta sensors. I added a Licor 6400 power cable to the soil CO2 enclosure, so if we forget the battery we can still do soil respiration measurements. Thereâ€™s at least one wasp in the box, so I put in moth balls in and left one cable entry open.

The non-functional ultra-sonic squirrel annoy-er was removed.

The solar panels and Arable done were cleaned.

We need to bring some medium split loom and 2 battery cables (1 red, 1 black) for next time.

We left at 12:15.

1 photos found

20180307TA_largeflock.JPG ( 2018-03-07 09:36:00 ) Full size: 1920x1440
Large flock of birds off of W Twitchell Island Road.