SGP/EBBR/E18 - Pressure Incorrect

The pressure sensor was replaced at E18 EBBR without the replacement being
noted by Site Ops and therefore without an indication of serial number and
thus correct calibration. The serial number of the sensor was observed 
during a PM (after months of confusion concerning the thing) and a several
month search for the calibration sheet at ANL, the CF, and the manufacturer
ensued.  The sheet was finally found and I confirmed that an incorrect
offset was being used (the same as used for the previous sensor). This is
an easy error to make as there are two models of pressure sensors (with
different calibration ranges) being used in the EBBR systems.  On June
17, 1999 the correct offset was entered into the CR10 and storage module
programming.  The pressure for the period should be increased by 6.757 kPa.
The result of the error is that Bowen ratio was underestimated by 6.8% on
average, Latent Heat Flux was overestimated by 3.6% on average, and Sensible
Heat Flux was underestimated by 3.6% on average.  The errors in the fluxes 
are smaller than the estimated 10% error in the Bowen ratio flux 
measurement technique and therefore the data does not need to be reprocessed.
Anyone performing area averages of pressure or looking at the variation in 
pressure over the CART Site should adjust the E18 EBBR pressure values for this
period using the offset error indicated above.

• bowen_ratio
• alt
• home_signal_15
• surface_soil_heat_flux_5
• surface_soil_heat_flux_4
• rh_bottom_fraction
• surface_soil_heat_flux_1
• vapor_pressure_bottom
• surface_soil_heat_flux_3
• surface_soil_heat_flux_2
• wdir_vec_mean
• wdir_vec_std
• surface_soil_heat_flux_avg
• base_time
• temp_reference
• vapor_pressure_top
• lat
• corr_soil_heat_flow_5
• corr_soil_heat_flow_4
• soil_temp_1
• soil_temp_3
• net_radiation
• soil_temp_2
• soil_temp_5
• temp_trh_top
• soil_temp_4
• soil_moisture_5
• soil_moisture_4
• temp_trh_bottom
• corr_soil_heat_flow_3
• corr_soil_heat_flow_2
• corr_soil_heat_flow_1
• energy_storage_change_5
• wspd_arith_mean
• time_offset
• energy_storage_change_1
• energy_storage_change_2
• energy_storage_change_3
• temp_air_bottom
• energy_storage_change_4
• soil_moisture_1
• soil_moisture_3
• soil_moisture_2
• soil_heat_flow_5
• wspd_vec_mean
• lon
• soil_heat_flow_1
• soil_heat_flow_2
• soil_heat_flow_3
• soil_heat_flow_4
• latent_heat_flux
• home_signal_30
• rh_top_fraction
• soil_heat_capacity_1
• soil_heat_capacity_2
• sensible_heat_flux
• soil_heat_capacity_3
• temp_air_top
• atmos_pressure
• soil_heat_capacity_4
• soil_heat_capacity_5

• Raw data stream - documentation not supported

• wdir_vec_std
• time_offset
• rh_top_fraction
• wdir_vec_mean
• lat
• vapor_pressure_bottom
• rh_bottom_fraction
• temp_trh_bottom
• atmos_pressure
• temp_trh_top
• alt
• temp_air_bottom
• base_time
• wspd_arith_mean
• vapor_pressure_top
• net_radiation
• temp_air_top
• home_signal
• temp_reference
• lon
• wspd_vec_mean