Field Notes

<--2017-10-04 10:20:00 | 2017-10-26 09:15:00-->
Other sites visited today: West Pond | Twitchell Alfalfa | Bouldin Alfalfa | East End

Bouldin Corn: 2017-10-19 09:45:00 (DOY 292)
Author: Daphne Szutu
Others: Kyle, Dennis

Summary: Regular data collection, swapped 7500 but H2O is suspect, power-cycled PRI/NDVI sensors

2017-10-19
Bouldin Corn

We arrived at 9:45. It was breezy, partly cloudy, and cool. The red gate by the road overpass was open, so we were able to take that short route to the tower. It doesn't look like they've plowed or done much to our field since harvest. The chambers were out in the field and our radiometers were dusty.

Dennis cleaned the radiometers and EC sensors, and he and Kyle swapped the 7500. sn 75H-2668 came down, sn 1594 went up. I uploaded the configuration file, "sn1594_0614_20170928Lab_cal.l7x", updated the pressure coefficients, and reset the 7550 box.

LI-7500 readings:
CO2 381.8 --> 417 after swap
H2O 759 --> 522 after swap
T 16.9 --> 17.5 after swap
P 100.9 --> 100.9 after swap
SS 94.2 --> 100.8 after swap

LI7700 readings:
CH4 1.92 --> 1.9 after cleaning
RSSI 27.7 --> 70 after cleaning

The H2O jumped -240 mmol/m3, which is more than we expected. This 7500 was calibrated in the lab on 7550 version 8.7.5 but is now installed at BC on 7550 version 8.5.0. This may cause the 7500 to be slightly off.

Two weeks ago, we swapped the 7550 at BC; the old 7550 was version 8.7.5, and the current 7550 was version 8.5.0. At that time, the H2O changed from 550 to 380 mmol/m3, a difference of -170 mmol/m3. So the total change from 4 weeks ago was -400 mmol/m3.

We might want to calibrate a 7500 on a 7550 with 8.5.0 to install at BC for next time.

We also had to power-cycle the 4 SRS sensors (NDVI in, NDVI out, PRI in, PRI out). These 4 sensors started reading NAN on 2017-10-09. We checked all connections and power and they seemed ok. The 3 CSI soil moisture sensors were on the same control port but seemed to be reading fine. We power-cycled the SRS sensors and tested them one-by-one using C3 and the Campbell Connect Terminal Emulator. The SRS and soil moisture sensors were all working so we reconnected them back to C5 and uploaded the original program.

We left at 11:25.

0 photos found

6 sets found

17 BC_met graphs found