Field Notes

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East End: 2018-10-28 12:10:00 (DOY 301)
Author: Daphne Szutu
Others: Alex, Karen, Mishal

Summary: Collected plants for litter decomp project, swapped 7500, re-tested tipping bucket, new gate combination

2018-10-28
East End

Alex, Karen, Mishal, and I arrived at 12:10. It was sunny and windy. The Twitchell gate was closed but not locked when we arrived. By the time we left, though, the gate was locked and the usual combination didn't work. Karen helped us communicate in Spanish with 4 farm workers who all tried to help us unlock the gate or get in touch with people who could. After about 30 minutes, we crossed paths with Bruce, who opened the gate for us and told us the new combination (4527).

Alex, Karen, and Mishal collected live and dead standing cattail and tule samples near the tower. Several plants were collected from 5 each previously marked patches east of the tower (and a tule patch north of the tower near the levee). Where possible whole plants were removed trying to avoid damage to the plant as much as possible, but for the live plants shears were used to sever the stem below the water surface. We gently wrapped the bushels in paper and kept cool and out of the sun. The samples were stored in large paper lawn/leaf bags overnight in the Hilgard basement cold room.

I swapped the 7500 for calibration: sn 75H-2176 came down and sn 75H-2150 went up. After the swap, I sent the new configuration file, updated the pressure coefficients, and reset the box.

LI-7500 readings:
(sn 75H-2176 --> sn 75H-2176 clean --> sn 75H-2150)
CO2 411ppm --> 407 --> 409
H2O 757ppm --> 765 --> 735
T 23.1C --> 23.4 --> 23.6
P 101.8kPa --> 101.8 --> 101.8
SS 100.5 --> 102 --> 94

I cleaned and re-tested the tipping bucket sn 50229-112. Last week, we got 94 tips and adjusted the set screws by one half turn. We connected the bucket to a CR23x and dribbled 475ml of water through it. This should result in 100 tips â€“ we got 98 tips. I adjusted the set screws in the bottom by one half turn clockwise (+2-3%).

We left at 13:45. On the way out, we stopped at the East Pond drain outlet and Alex confirmed it was still flowing.

3 photos found

20181028EE_MishalDaphneKaren.jpg ( 2018-10-28 11:57:31 ) Full size: 1440x1920
Mishal, Daphne and Karen ready to harvest litter for decomposition