SGP/SWATS/E1 - Reprocess: Wrong Calibration

Two sensor connections were switched. The East 125-cm sensor was plugged into the East 
85-cm sensor's connection, and vice versa. Technicians corrected the problem on 1440 GMT, 
08/02/00, and returned the instrument to service 10 minutes later at 1450 GMT. As the 
datalogger was confusing the 2 sensors, incorrect calibrations were applied.

The correct calibrations can be applied to the raw data to obtain the correct temperature 
rises, soil moisture, etc. However, this is a rather large amount of work to apply toward 
just 1 measurement profile.  This has been identified as a medium priority reprocessing 
task.

• Volumetric Water Content, East Profile(watcont_E)
• Soil Temperature, East Profile(tsoil_E)
• Sensor Temperature Rise, East Profile(trise_E)
• serial_numbers_E
• Soil Water Potential, East Profile(soilwatpot_E)

SGP/SWATS/E1 - Incorrect Soil Moisture Data, 5cm E

The temperature rise readings from the 5-cm depth on the east profile (trise_E) were 
incorrect. This also caused the matric potential (soilwatpot_E) and water content (watcont_E) 
data for the 5-cm depth to be incorrect.

• Volumetric Water Content, East Profile(watcont_E)
• Sensor Temperature Rise, East Profile(trise_E)
• Soil Water Potential, East Profile(soilwatpot_E)

SGP/SWATS/E1 - Sensor failure, 85cm W

The 85-west sensor failed and began reporting missing values (-9999) with intermittent 
incorrect values.

Instrument removed from service 20091014.

• Sensor Temperature Rise, West Profile(trise_W)
• Soil Water Potential, West Profile(soilwatpot_W)
• Volumetric Water Content, West Profile(watcont_W)
• Soil Temperature, West Profile(tsoil_W)

SGP/SWATS/E1 - Sensor failure, 25cm E

The soil sensor at the 25-cm depth on the East profile began reporting missing or 
incorrect values for all soil moisture measurements (trise, tsoil, soilwatpot, watcont).

Instrument removed from service 20091014.

• Volumetric Water Content, East Profile(watcont_E)
• Soil Temperature, East Profile(tsoil_E)
• Sensor Temperature Rise, East Profile(trise_E)
• Soil Water Potential, East Profile(soilwatpot_E)

SGP/SWATS/E1 - Questionable Soil Moisture Data

Between the 06GMT and 07GMT measurements on January 14th, it appears that some sort of 
non-atmospheric moisture source affected the 4 shallowest sensors (5-cm West & East, 15-cm 
West & East). No precipitation was recorded at the site, but data indicate a sharp 
increase in soil moisture that caused suspicious behavior that gradually lessened through 
January 23rd. Animal intrusion, but more probably adolescent mischief, is suspected.

Be aware that the soil moisture responses on January 14th most likely are not due to 
natural causes. For the remainder of the period, soil moisture measurements at 5cm and 15cm 
may be adversely affected.

• Volumetric Water Content, East Profile(watcont_E)
• Sensor Temperature Rise, East Profile(trise_E)
• Sensor Temperature Rise, West Profile(trise_W)
• Soil Water Potential, West Profile(soilwatpot_W)
• Volumetric Water Content, West Profile(watcont_W)
• Soil Water Potential, East Profile(soilwatpot_E)

SGP/SWATS/E1 - Sensor failure, 5cm E

Both trise and tsoil for the 5cm E sensor began to drop out intermittently reporting both 
incorrect values and values of -9999 starting on 08/18/2007.  Since this date, there have 
been periods where values of -9999 have been reported continuously for months at a time, 
but the sensor always seems to come back eventually and report values that appear 
correct.  

Currently, this sensor is reporting normal values again but has failed as recently as 
10/08/08.  When this sensor is failing, it typically impacts tsoil_E, trise_E, soilwatpot_E, 
and watcont_E.  However, there are cases where tsoil_E appears OK while the other 
variables are incorrect.

Instrument was removed from service 20091014.

• Volumetric Water Content, East Profile(watcont_E)
• Soil Temperature, East Profile(tsoil_E)
• Sensor Temperature Rise, East Profile(trise_E)
• Soil Water Potential, East Profile(soilwatpot_E)

SGP/SWATS/E1 - Sensor failure, 85cm E

Both trise and tsoil for the 85cm E sensor dropped out reporting values of -9999 starting 
on 08/24/2005.  Interestingly, both this sensor and the one at 85 cm W (D040730.1) began 
to report data again June-August 2006.  Both sensors have reported values of -9999 after 
this brief period through the current date.  This problem impacts tsoil_E, trise_E, 
soilwatpot_E, and watcont_E. 

Instrument was removed from service 20091014.

• Volumetric Water Content, East Profile(watcont_E)
• Soil Temperature, East Profile(tsoil_E)
• Sensor Temperature Rise, East Profile(trise_E)
• Soil Water Potential, East Profile(soilwatpot_E)

SGP/SWATS/E1 - Sensor failure, 15cm W

Both trise and tsoil for the 15cm W sensor began to drop out intermittently reporting both 
incorrect values and values of -9999 starting on 05/29/2008.  Currently, this sensor is 
reporting mainly values of -9999 for all measurements with a few random incorrect values 
from time to time.  This problem impacts tsoil_W, trise_W, soilwatpot_W, and watcont_W.

Instrument removed from service 20091014.

• Sensor Temperature Rise, West Profile(trise_W)
• Soil Water Potential, West Profile(soilwatpot_W)
• Volumetric Water Content, West Profile(watcont_W)
• Soil Temperature, West Profile(tsoil_W)

SGP/SWATS/E1 - Instrument failure

The diurnal temperature change in the tsoil measurements from all sensors installed below 
5 cm at this facility appear questionable.  On a daily basis, the diurnal trends in the 
tsoil measurements from depths below 5 cm did not match the above ground tref measurements 
or the tsoil measurements from the 5 cm W sensor (the 5 cm E sensor has failed). The 
tsoil measurements from these deeper sensors began to decrease prior to solar noon nearly 
every day. Also, the magnitudes of the diurnal change in these instruments appear to be the 
same for all sensors (Normally, the diurnal changes in tsoil are damped as we progress 
deeper below the surface).  

Attempts to correct the problem were unsuccessful until the time of site decommissioning.  
This facility was decommissioned and maintenance efforts ceased 10/1/2009.

• Soil Temperature, East Profile(tsoil_E)
• Soil Temperature, West Profile(tsoil_W)