Field Notes

<--2022-07-26 10:00:00 | 2022-08-03 12:35:00-->
Phenocam link: Searching...

Mayberry: 2022-08-01 13:00:00 (DOY 213)
Author: Daphne Szutu
Others:

Summary: Reinstalled sonic and re-pinned to 7700 auxiliary input, changed GHG output columns, battery bank needs testing, water level decreasing

2022-08-01
Mayberry

I arrived around 13:00 PDT. Today's visit was to continue troubleshooting the sonic. I reinstalled the sonic sn 153805 and the original sonic cable.

I had tested the sonic and sonic cable in the lab with Joe's help over e-mail. Both tested fine. In the lab, I had mated the sonic cable with an Eosense cable and used the conductivity setting on the voltmeter to find the 4 eosense wires that corresponded to outputs 1-4. At rest (while I was standing still next to the sonic), the voltages were around +/- 8mV. I then used a fan to test U, V, W. The voltages went up to around 150mV. Placing the fan on the opposite side of the sonic produced about the same magnitude voltage with the opposite sign. SOS (output 4) was around 1.7V and didn't change much with the fan, as expected. I wired the Eosense cable to a CR1000 with a NL115 and ran it overnight, storing 30min and 20Hz data on an 8gb card. The data the next morning seemed reasonable. SOS had the same pattern as PanelT.

At the site, it was mostly overcast and a bit muggy. There were sprinkles on and off this morning in Berkeley (actual, measurable precipitation!). Lots of virga in the sky to the N and W throughout the day. The sun started peeking out around 15:00 PDT but a cool breeze kept it from getting too hot. The water was greenish and the staff gauge read 42cm. The water level has been steadily dropping here.

First, I again connected the sonic to the 7550 box. Visually the 7550 Auxiliary Input port looked perfectly fine and I shot some canned air into it. In the 7550 software, "U" and "SOS" were both reading -9999 as Carlos and Ari had seen last week. This should have been a clue--since the sonic is outputting an analog signal, a "zero" reading should be hovering around 0mV, not at -9999. Instead of "U", etc. I should have been plotting "7550 Auxiliary Input 1", etc. because our sonic is attached to the 7550 Auxiliary Input port. The variables "U", "V", "W", and "SOS" in the 7550 software are used for the newer SmartFlux system, not our older wiring system, but there's no way Ari and Carlos would have known that. From the -9999 displayed, I concluded there was something wrong with the 7550 Auxiliary Input port.

I re-pinned the sonic for the 7700 Auxiliary Input. The 7550 is expecting data from four DE signals (on pins 1-8) and the 7700 is expecting data from four SE signals (pins 1-4). The sonic pins stay the same (8, 14, 9, 15 for outputs 1-4 respectively; 10, 16, and/or 17 for analog ground), but the wire color changes to correspond to the correct pin on the analog end.

7550 pinout:
Sonic pin -> Licor wire color
8 -> White
14 -> Green
9 -> Gray
15 -> Blue
10, 16, 17 -> Brown, Yellow, Pink, Red
Not connected -> Tan

7700 pinout:
Sonic pin -> Licor wire color (or Harting wire color)
8 -> White (Brown)
14 -> Brown (Blue)
9 -> Green (White)
15 -> Yellow (Green)
10 or 16 or 17 -> Tan (Violet)

In the lab, I had already added a pin to the tan wire. However, in the field I realized that the brown and yellow wires had been soldered together to a single pin because they had both been used for AG in the 7550 pinout. For the 7700 pinout, the brown wire has to go in sonic pin 14 and the yellow wire has to go in sonic pin 15. I had to pull out the field soldering iron to separate the brown and yellow wires. I stole a solder pin from the red wire since it wasn't used for the 7700 pinout. To change it back to the 7550 pinout, the red and pink wires can go together in one pin. At this point I had run out of butane for the iron so the red wire is still loose.

After re-pinning the sonic connector, I connected the sonic to the 7700 and voila, reasonable data on the 7700 auxiliary channels! I updated the auxiliary coefficients and added the 7700 auxiliary inputs 1-4 to the GHG output. I did not change the 7550 output columns so they're still saving junk for the 7550 auxiliary inputs 1-4.

Last week Ari and Carlos had marked the sonic orientation and measured it at 7 deg true N. Today I matched up the sonic with their mark, but I measured it at 16 deg true N. I tried to split the difference and the final sonic heading was 10 deg true N.

(When I installed this sonic on 2022-01-02, I measured the heading at 23 deg true N. It should not have moved before it was removed on 2022-07-26. Not sure which heading is closest to the truth--23 or 7 or something else).

I'm not sure if the sonic would work connected to the 7550 Auxiliary Input port. Maybe the problem in the end was just a loose connection to the 7550 box, or maybe something more. To test in the future, we would need to refill the soldering iron with butane to connect the red and pink wires together into one pin to complete the 7550 pinout.

I cleaned the flux and rad sensors. The 7700 had a low RSSI because of spiderwebs (and dead insects) caught between the spars. The wash/spin ran once while I was there but it didn't do much because the spiderwebs were above the spray. The wash reservoir was 1/3 full; I refilled it. The eddy clock was only 10s slow so I left it as is for now.

The 7500 read: 434ppm CO2, 737mmol/m3 H2O, 26.1C, 100.8kPa, 101SS after cleaning
The 7700 read: 2.0ppm CH4, 12RSSI – 79 after cleaning

I cleaned the dusty solar panels and left around 16:45 PDT.

I found a baby caterpillar on my glove at the end of the day. I wonder if there will be another infestation this year.

Pre-dawn BattV is starting to drop <11V. I wonder if this is messing anything up with the 7550 or other flux sensors. BattV was ok from 2022-05-19 to 2022-06-08 when the 7700 was off the tower for repair, so maybe we are at the limit of our battery bank. We should test the batteries--maybe the short in the camera power cable last winter killed a battery or two.

0 photos found

11 sets found

7 MB_flux graphs found