FKB/MET/M1 - Optical Rain Gauge Data Incorrect

The Optical Raingauge (ORG) data was incorrect during the listed times.  Ice/frost was 
forming on the lenses causing the ORG to believe there was precipitation occurring.

• Rain, surface, 1-min avg(precip_rate_mean)
• precip_rate_min
• precip_rate_max
• precip_rate_sd

FKB/MET/M1 - ORG Data incorrect during calibration

The ORG data was incorrect during calibration checks.  The check mimics a precipiation 
event so the precip amounts that were collected were not actually measured.

• Rain, surface, 1-min avg(precip_rate_mean)
• precip_rate_min
• precip_rate_max
• precip_rate_sd

FKB/MET/M1 - Optical Rain Gauge Data Incorrect

Precipitation was being reported on days with no rain.  Problems with the grounding and 
the orientation of the receiver facing south (sunlight in the optics) caused erroneous 
readings.

• Rain, surface, 1-min avg(precip_rate_mean)
• precip_rate_min
• precip_rate_max
• precip_rate_sd
• org_carrier_mean

FKB/MET/M1 - Optical Rain Gage Reporting Precip Constantly

During the time period listed the ORG reported precip consistently.  Reason unknown as 
deployment ended before resolution of problem.

• Rain, surface, 1-min avg(precip_rate_mean)
• precip_rate_min
• precip_rate_max
• precip_rate_sd

HFE/MET/M1 -  Wind Speed data contain offset due to induced voltage

The marine model of the RM Young wind sensor needs twisted pair shielded cable.  The 
manufacturer did not originally supply the pigtail with twisted pair shielded cable.  Use of 
twisted pair shielded cable for the rest of the cable run to the logger was also not 
specified.  This caused an induced voltage in the wind speed line from the wind direction 
excitation.  The induced voltage varied from sensor to sensor and probably changed anytime 
the cable was replaced or parts of the wind sensor were repaired or replaced. The induced 
voltage has been seen to vary from 0.15 m/s to as much as 1.08 m/s.

• wind_spd_arith_max
• Vector-averaged Wind Speed(wind_spd_vec_avg)
• wind_spd_arith_min
• wind_spd_arith_sd
• Wind speed, lower, 1-min avg(wind_spd_arith_avg)

FKB/MET/M1 - Wind Speed data contain offset due to induced voltage

The marine model of the RM Young wind sensor needs twisted pair shielded cable.  The 
manufacturer did not originally supply the pigtail with twisted pair shielded cable.  Use of 
twisted pair shielded cable for the rest of the cable run to the logger was also not 
specified.  This caused an induced voltage in the wind speed line from the wind direction 
excitation.  The induced voltage varied from sensor to sensor and probably changed anytime 
the cable was replaced or parts of the wind sensor were repaired or replaced. The induced 
voltage has been seen to vary from 0.15 m/s to as much as 1.08 m/s.

• wind_spd_arith_min
• wind_spd_arith_sd
• wind_spd_arith_max
• Wind speed, lower, 1-min avg(wind_spd_arith_avg)
• Vector-averaged Wind Speed(wind_spd_vec_avg)

HFE/MET/M1 - Intermittent barometer failure

Intermittent barometer failure occurred throughout the deployment.  We were unable to 
pinpoint the cause of the failure.  Typically one or two minutes of missing data occurred 
every few days.

Since pressure data is typically invariant over 1 minute, linear interpolation should be 
fine to fill in missing data.

• Atmospheric pressure(atmos_pressure)

HFE/MET/M1 - Intermittent PWD data

The Present Weather Detector had intermittent missing values throughout this deployment.  
Missing values occurred almost everyday, usually just one or two minutes per day.

• pwd_cumul_snow
• Average 10 min visibility(pwd_avg_vis_10_min)
• pwd_pw_code_15_min
• pwd_id
• pwd_err_code
• Average 1 min visibility(pwd_avg_vis_1_min)
• pwd_pw_code_1_hr
• pwd_avg_H2O_int_1_min
• pwd_pw_code_inst
• pwd_cumul_water

HFE/MET/M1 - ORG Measuring Ice Crystals or Fog

The ORG was measuring consistent values for long periods of time.  Typically this is 
indicative of fog, ice crystals in the air or poor performance of the lens heaters.

• precip_rate_sd
• Rain, surface, 1-min avg(precip_rate_mean)
• precip_rate_max
• precip_rate_min

HFE/MET/M1 - Induced voltage on wind speed sensor cable

The cable for the wind monitor is not a twisted pair shielded cable.  This caused an 
induced voltage on the wind sensor wires from the wind direction measurement excitation 
voltage.  A small offset is added into the wind speeds.  This value varies.  Most frequently 
the values of 0.49, 0.588 and 0.686 m/s were added into the wind speed.  On 11/27/2008 the 
value jumped to 0.98 m/s for most of the day.

• wind_spd_arith_max
• Vector-averaged Wind Speed(wind_spd_vec_avg)
• wind_spd_arith_min
• wind_spd_arith_sd
• Wind speed, lower, 1-min avg(wind_spd_arith_avg)

GRW/MET/M1 - Tower lowered during installation

Data was collected during set up and installation.  Any data collected is suspect due to 
the tower being lowered and calibration checks occurring.  The data should be viewed 
critically before being used.

• pwd_avg_H2O_int_1_min
• org_carrier_mean
• Rain, surface, 1-min avg(precip_rate_mean)
• pwd_pw_code_15_min
• pwd_pw_code_inst
• wind_spd_arith_sd
• pwd_cumul_water
• Temperature mean(temp_mean)
• pwd_cumul_snow
• Average 1 min visibility(pwd_avg_vis_1_min)
• Relative humidity mean(relh_mean)
• Vector-averaged Wind Speed(wind_spd_vec_avg)
• precip_rate_max
• Wind speed, lower, 1-min avg(wind_spd_arith_avg)
• pwd_err_code
• relh_sd
• logger_voltage
• Atmospheric pressure(atmos_pressure)
• temp_sd
• wind_dir_sd
• precip_rate_sd
• Vapor pressure mean(vappress_mean)
• pwd_id
• wind_spd_arith_min
• logger_temp
• precip_rate_min
• wind_spd_arith_max
• pwd_pw_code_1_hr
• vappress_sd
• Vector-averaged Wind Direction(wind_dir_vec_avg)
• Average 10 min visibility(pwd_avg_vis_10_min)

GRW/MET/M1 - Temperature/RH Aspirator Failure

The aspirator fan on the solar shield failed causing incorrect readings on the temp, RH 
and calculated variables.

• Temperature mean(temp_mean)
• relh_sd
• Vapor pressure mean(vappress_mean)
• Relative humidity mean(relh_mean)
• vappress_sd
• temp_sd