SGP/NIMFR/C1 - Tube heater not functioning

The tube heater is not functioning properly. On 6/27/06, site operations personnel 
indicated the heater plug was found to be disconnected (The heater became disconnected on 
6/12/06).  It was reconnected and while the head temperature returned to normal, the tube 
temperatures are still bad.

The purpose of the tube heater is to help prevent condensation from forming on the window. 
 The mentor has not noticed any problems with the data resulting from the tube heater 
malfunction.  However, since the instrument is technically not fully functional, this DQR 
is being issued.

A repair attempt was made on June 7, 2007 that resulted in the tube temperatures reaching 
at times into the upper 50s and sometimes even the lower 60s.  The high tube temps 
influenced the head temperature causing it to move into the upper 40s and sometimes the lower 
50s.

The heater was repaired on Oct 11, 2007.  Though repaired, the instrument was configured 
to keep the tube temp in the lower 20s (deg C).  This is acceptable, though to keep with 
instrument specifications the setting was adjusted to keep the temps in the upper 30s (deg 
C).  This occurred on 8 Jan, 2008.

• Cosine of Solar Zenith Angle(cosine_solar_zenith_angle)
• Direct Horizontal Broadband Irradiance, broadband scale applied(direct_horizontal_broadband)
• Normalized filter function data, filter 4, wavelength value obtained during
  bench calibrations(wavelength_filter4)
• Nominal calibration factor, applied to filter2 data(nominal_calibration_factor_filter2)
• Offset subtracted from direct normal filter4 data(offset_filter4)
• Normalized filter function data, filter 2, measured transmittance value obtained
  during bench calibrations(normalized_transmittance_filter2)
• Tube Temperature(tube_temp)
• Normalized filter function data, filter 2, wavelength value obtained during
  bench calibrations(wavelength_filter2)
• Offset subtracted from direct normal filter2 data(offset_filter2)
• Direct Normal Broadband Irradiance broadband scale applied(direct_normal_broadband)
• Direct Normal Narrowband Irradiance, Filter 3(direct_normal_narrowband_filter3)
• Nominal calibration factor, applied to filter1 data(nominal_calibration_factor_filter1)
• Data Logger Supply Voltage(logger_volt)
• Second Detector Temperature(head_temp2)
• Normalized filter function data, filter 1, wavelength value obtained during
  bench calibrations(wavelength_filter1)
• Direct Normal Narrowband Irradiance, Filter 2(direct_normal_narrowband_filter2)
• Narrowband Direct Horizontal Irradiance, Filter 6(direct_horizontal_narrowband_filter6)
• Normalized filter function data, filter 3, measured transmittance value obtained
  during bench calibrations(normalized_transmittance_filter3)
• Direct Normal Narrowband Irradiance, Filter 1(direct_normal_narrowband_filter1)
• base time(base_time)
• Narrowband Direct Horizontal Irradiance, Filter 1(direct_horizontal_narrowband_filter1)
• Airmasses(airmass)
• Normalized filter function data, filter 6, measured transmittance value obtained
  during bench calibrations(normalized_transmittance_filter6)
• Normalized filter function data, filter 5, measured transmittance value obtained
  during bench calibrations(normalized_transmittance_filter5)
• Dummy altitude for Zeb(alt)
• lat(lat)
• Detector Temperature(head_temp)
• Normalized filter function data, filter 4, measured transmittance value obtained
  during bench calibrations(normalized_transmittance_filter4)
• lon(lon)
• Offset subtracted from direct normal filter5 data(offset_filter5)
• time(time)
• Nominal calibration factor, applied to broadband data(nominal_calibration_factor_broadband)
• Narrowband Direct Horizontal Irradiance, Filter 5(direct_horizontal_narrowband_filter5)
• Normalized filter function data, filter 1, measured transmittance value obtained
  during bench calibrations(normalized_transmittance_filter1)
• Nominal calibration factor, applied to filter3 data(nominal_calibration_factor_filter3)
• Offset subtracted from direct normal filter1 data(offset_filter1)
• Offset subtracted from direct normal broadband data(offset_broadband)
• Nominal calibration factor, applied to filter6 data(nominal_calibration_factor_filter6)
• Direct Normal Narrowband Irradiance, Filter 4(direct_normal_narrowband_filter4)
• Narrowband Direct Horizontal Irradiance, Filter 3(direct_horizontal_narrowband_filter3)
• Azimuth angle(azimuth_angle)
• Offset subtracted from direct normal filter3 data(offset_filter3)
• Normalized filter function data, filter 3, wavelength value obtained during
  bench calibrations(wavelength_filter3)
• Nominal calibration factor, applied to filter5 data(nominal_calibration_factor_filter5)
• Elevation Angle(elevation_angle)
• Offset subtracted from direct normal filter6 data(offset_filter6)
• Narrowband Direct Horizontal Irradiance, Filter 4(direct_horizontal_narrowband_filter4)
• Solar zenith angle(solar_zenith_angle)
• Nominal calibration factor, applied to filter4 data(nominal_calibration_factor_filter4)
• Normalized filter function data, filter 6, wavelength value obtained during
  bench calibrations(wavelength_filter6)
• Direct Normal Narrowband Irradiance, Filter 6(direct_normal_narrowband_filter6)
• Normalized filter function data, filter 5, wavelength value obtained during
  bench calibrations(wavelength_filter5)
• Narrowband Direct Horizontal Irradiance, Filter 2(direct_horizontal_narrowband_filter2)
• Direct Normal Narrowband Irradiance, Filter 5(direct_normal_narrowband_filter5)
• Time offset of tweaks from base_time(time_offset)

• Detector Temperature(head_temp)
• Direct Normal Narrowband Irradiance, Filter 5(direct_normal_narrowband_filter5)
• Offset subtracted from direct normal filter5 data(offset_filter5)
• Data Logger Supply Voltage(logger_volt)
• Direct Normal Narrowband Irradiance, Filter 2, raw data as read(direct_normal_narrowband_filter2_raw)
• Direct Normal Narrowband Irradiance, Filter 4(direct_normal_narrowband_filter4)
• Offset subtracted from direct normal filter4 data(offset_filter4)
• Offset subtracted from direct normal broadband data(offset_broadband)
• Direct Normal Narrowband Irradiance, Filter 5, raw data as read(direct_normal_narrowband_filter5_raw)
• Tube Temperature(tube_temp)
• Offset subtracted from direct normal filter1 data(offset_filter1)
• lat(lat)
• Direct Normal Narrowband Irradiance, Filter 1(direct_normal_narrowband_filter1)
• Second Detector Temperature(head_temp2)
• time(time)
• Direct Normal Narrowband Irradiance, Filter 6, raw data as read(direct_normal_narrowband_filter6_raw)
• Dummy altitude for Zeb(alt)
• Direct Normal Broadband Irradiance, raw data as read(direct_normal_broadband_raw)
• Direct Normal Narrowband Irradiance, Filter 2(direct_normal_narrowband_filter2)
• lon(lon)
• Direct Normal Narrowband Irradiance, Filter 4, raw data as read(direct_normal_narrowband_filter4_raw)
• Time offset of tweaks from base_time(time_offset)
• Direct Normal Narrowband Irradiance, Filter 1, raw data as read(direct_normal_narrowband_filter1_raw)
• Direct Normal Narrowband Irradiance, Filter 3(direct_normal_narrowband_filter3)
• Direct Normal Narrowband Irradiance, Filter 6(direct_normal_narrowband_filter6)
• Offset subtracted from direct normal filter6 data(offset_filter6)
• Offset subtracted from direct normal filter2 data(offset_filter2)
• Direct Normal Broadband Irradiance broadband scale applied(direct_normal_broadband)
• base time(base_time)
• Direct Normal Narrowband Irradiance, Filter 3, raw data as read(direct_normal_narrowband_filter3_raw)
• Offset subtracted from direct normal filter3 data(offset_filter3)