Field Notes
<--2001-06-01 15:08:00 | 2001-06-08 14:33:00-->Other sites visited today: Tonzi
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Vaira: 2001-06-06 13:53:00 (DOY 157)
Author: Ted Hehn
Others: Nancy, Jinwu, Liukang
Summary: Trouble shooting with pressure bomb, checked flux towers, started aspirator at Tonzi.
| I traveled to the site on the evening of June 6 slept in the van and met with Nancy and Jinwu at 8:00 on 7 June. They were having trouble with the pressure bomb so I spent an hour or more trouble shooting that and getting it to work. It appears that the instrument fell over or the regulator was dropped and consequently will need to be repaired or replaced. Upon opening the tower flux system I discovered that it had stopped taking data last Saturday at 0930 resulting in a 5 day loss of data. Rebooting the PC did not solve the problem so I shut the power down at the solar regulator to reboot the sonic. This was not successful. Upon climbing the tower I disconnected all power and digital I/O lines from the sonic and then began investigating the PAR sensors. The PAR sensors were disconnected from the data logger and I measured the voltage with a multimeter which indicated about 2.3 mVolts and this is what the data logger was showing the voltage to be both with ground and without ground. This indicates that the sensors sensitivity must have changed and I can't really do anything about it until I have another new sensor to compare to. I reconnected the leads to the sonic and climbed down the tower and the pc was now working and collecting data. I don't know why the sonic failed but would guess that there was some form of static charge built up that caused it to crash. Disconnecting all leads tends to allow this charge to bleed off. Next, I began diagnostics on the tower MD9 - using a spare pc, 532 interface, MD9, and short coax line I verified that the 23x and md9 on the tower were working. Next I used the spare system to attempt communication thru the long coax line and this failed so the problem was in that long line. My multimeter indicated that there was continuity so I simply replaced the connector on the down side and this did not correct it. Replacing the up side connector corrected the problem so I suspect either a short in the connector or a cold solder joint that rectified the hi frequency digital signal to straight DC. Anyway the problem is solved and renaming task is now operational. At that point Liukang returned from Vaira an informed me that we had lost communication with the 23x. I replaced the tower PC (widows 98) with the with windows NT pc. Also started the aspirator at the tonzi site. |
Field Data
No tank data
No VR Well data found
No TZ Moisture Point data found
No VR Moisture Point data found
No TZ grass heigth found
No VR grass heigth found
No VR Tree DBH found
No water potential data found
No VR Grass Biomass data found
No VR OakLeaves Biomass data found
No VR PineNeedles Biomass data found
0 photos found
9 sets found
16 VR_met graphs found
2 VR_flux graphs found
No data found for VR_soilco2.
No data found for VR_pond.
Can't check TZVR_mixed
No data found for VR_fd.
No data found for VR_processed.
No data found for VR_arable.
No data found for VR_soilvue.