Field Notes

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Other sites visited today: Gilbert Tract | East End
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Mayberry: 2025-01-29 13:40:00 (DOY 29)
Author: Robert Shortt
Others: Daphne

Summary: Replaced the floating bucket and sonic rangefinder. Re-stripped wiring on the HMP fan. Sensors majorly pooped on. First download of miniCH4 data. 7700 time sync error--missing 2 weeks of CH4 data.

We arrived at 1:40pm. The weather was mostly sunny and mild, with light wind. The staff gauge read 58cm.

I got in the water and replaced the floating bucket with a new one (black). The old one (orange) was disintegrating, had broken off of the boom, and was floating in the water next to the boom. The boom was not floating at all. The miniDOT and eosGP data had a sharp drop on 2025-01-19, so that's probably when the bucket completely broke and the sensors were probably buried in mud at that time. Daphne handled the data download at this location, all looked normal.

The power wire to the HMP aspirator was rusted and broken, and the IRGAs were both completely covered in bird poop. No CO2 data after 2025-01-23 because of low signal strength.

I swapped out the old HMP housing with a cleaned-up housing + new aspirator and re-stripped the wiring for the aspirator. Even though there was charge passing through the wiring hub (screw terminal) (13.5V), I could not hear the fan running. We decided to check the data for sharp rises in sunlight next time and to leave it as-is.

There was also a leak in the 7700 water hose where the reservoir connects inside the box to the tubing outlet. Daphne managed to cut it and use some excess in the line to fix it. We refilled the empty wash reservoir and closed the lid.

The range finder looks bad sn 68574-2; Daphne replaced it with a new one sn 68574-4. Wired this one into 5V this time!

We downloaded the miniDOT data and swapped the miniDOT and water level desiccant.

There was a 7700 clock sync error when we arrived. Daphne adjusted the 7550 time by 1 second, which made the clock sync error go away. She reset the 7550 box and confirmed everything was ok. Because of the time sync error, there's no CH4 data since our last site visit when we swapped the 7500 for calibration.

7500 dirty read: -475pm CO2, -121mmol/m3 H2O, 16.6C, 101.3kPa, 12SS
7500 clean read: 398pm CO2, 540mmol/m3 H2O, 16.6C, 101.3kPa, 96.7SS
7700 read: 2.0ppm CH4, 41RSSI — 70 after cleaning

She checked the conductivity sensor as part of its routine quarterly check and confirmed that the orifice was clear.

We measured the surface water conductivity.
Surface, 2021uS, 11.1C

Daphne connected to the miniCH4 through CoolTerm and downloaded the miniCH4 data. She erased the logged data and set the next start time to 14:30 (download time was 14:04). She restarted sampling.

We left at about 2:55pm.

0 photos found

11 sets found

7 MB_flux graphs found