Field Notes

West Pond: 2023-09-28 13:25:00 (DOY 271)
Author: Daphne Szutu
Others: Robert

Summary: Regular data collection/cleaning, losing power nightly--trimmed willow by solar panels, 7500 PLL error--fixed?, disconnected 7700 to save power

2023-09-28
West Pond

Robert and I arrived at 13:25 PDT. It was warm and sunny with no cooling breeze. There were many wasps buzzing about—one stung Robert at the very end while we were packing up the car. I gave him the last “sting relief” pad from our first aid kit—I need to buy more.

The inlet was off and the water level has gone down a little. The staff gauge read 71cm.

Robert got started trimming the willow tree south of the solar panels. He removed many of the branches.

I downloaded met, cam, and USB GHG. We are still losing power every night here, starting around 21:00. The 7700 also had a time sync error and the 7500 had a PLL error. I corrected the time sync error by adjusting the eddy clock to match the laptop time (<1 min difference). I corrected the PLL error by disconnecting and reconnecting the IRGA cable from the sensor. The chopper motor sounded louder than usual when booting up. The 7500 sn 75H-2514 is from 2014 and has never been back to the factory. I’m not sure if all the power cycles have affected it, or if it’s just wearing down. I’ll bring a replacement 7500 next time (it’s due for calibration anyways).

I checked the 7700 heater settings. Top and bottom heaters were both set to 10% (most other sites had 5% power). I dialed it back to 1% power and kept it on summer hours (21:00 to 06:00) to try to save power. Later I just disconnected it completely to save on power.

I checked on the batteries and charge controller. The charge controller numbers seemed normal and the tower was pulling about 0.7A. Both of the connected batteries tested good. The third battery (not connected to anything) tested on the border of good/weak. I called Joe, and he said there should be one more ok battery in the lab. Next time we can connect it to bring the system up to 4 batteries. He also suggested unplugging the 7700—no methane data at all but more data overall for gapfilling.

I went back to the main tower to disconnect the 7700 power.

I checked that the 7550 was still working and restarted the Canon camera before we left.

The 7500 read: 419ppm CO2, 530mmol/m3, 29.4C, 101.1kPA, 100SS – 100 after cleaning
The 7700 read: 2.3ppm CH4, 66RSSI – 82 after cleaning.

We left at 14:25 PDT.

Flux data 9/12-9/19 is missing. Might be on datamule.

0 photos found

8 sets found

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1 WP_DO graphs found