| DQR ID | Subject | Data Streams Affected |
|---|---|---|
| D000801.4 | SGP/AOS/C1 - Nephelometer failure | sgpaosC1.a0, sgpaosauxC1.a0 |
| D000801.5 | SGP/AOS/C1 - Nephelometer failure | sgpaosC1.a0, sgpaosauxC1.a0 |
| D980528.1 | SGP/AOS/C1 - Optical Particle Counter (PCASP-X) down | sgpaosC1.a0, sgpaosauxC1.a0 |
| D990611.1 | SGP/AOS/C1 - Ozone Instrument Failure | sgpaosC1.a0, sgpaosauxC1.a0 |
| D990614.1 | SGP/AOS/C1 - Invalid absorption data | sgpaosC1.a0, sgpaosauxC1.a0 |
| D990618.1 | SGP/AOS/C1 - Incorrect absorption and scattering data | sgpaosC1.a0 |
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 06/20/2000 | 1340 | 07/03/2000 | 1833 |
| Subject: | SGP/AOS/C1 - Nephelometer failure |
| DataStreams: | sgpaosC1.a0, sgpaosauxC1.a0 |
| Description: | An inexperienced AOS technician inadvertently closed off the flow to the dual-nephelometer humidograph system during a Friday Preventative Maintenance. This resulted in liquid water getting into the humidified nephelometer. Flow was restored to the system on Monday, but the nephelometers were producing strange data. A number of tests were performed over the next few days to remotely troubleshoot the situation, to no avail. Eventually, the decision was made to pull both nephelometers and return them to Boulder for repair. This DQR refers only to the reference nephelometer, which was out of service for 2 periods due to 2 separate problems. This DQR is for the second period, from 000620 (1340 GMT) to 000703 (1833 GMT). Light absorption measurements are invalid whenever the reference nephelometer is not operational, because those data are required for correction of the absorption data. |
| Measurements: | sgpaosauxC1.a0:
sgpaosC1.a0:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 06/02/2000 | 1842 | 07/03/2000 | 1833 |
| Subject: | SGP/AOS/C1 - Nephelometer failure |
| DataStreams: | sgpaosC1.a0, sgpaosauxC1.a0 |
| Description: | An inexperienced AOS technician inadvertently closed off the flow to the dual-nephelometer humidograph system during a Friday Preventative Maintenance. This resulted in liquid water getting into the humidified nephelometer. Flow was restored to the system on Monday, but the nephelometers were producing strange data. A number of tests were performed over the next few days to remotely troubleshoot the situation, to no avail. Eventually, the decision was made to pull both nephelometers and return them to Boulder for repair. This DQR refers only to the humidified nephelometer, which was out of service for the entire period from 000602 through 000703. |
| Measurements: | sgpaosauxC1.a0:
sgpaosC1.a0:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 07/01/1997 | 0936 | 07/03/1997 | 1556 |
| 08/01/1997 | 1329 | 08/08/1997 | 1348 |
| 05/05/1998 | 0926 | 06/16/1998 | 1505 |
| 06/09/1999 | 0824 | 07/26/1999 | 2205 |
| 09/08/2000 | 0426 | 10/13/2000 | 1630 |
| 05/17/2002 | 0602 | 05/20/2005 | 1847 |
| 05/23/2002 | 2011 | 05/31/2002 | 1258 |
| 09/09/2002 | 0000 | 10/07/2002 | 1905 |
| Subject: | SGP/AOS/C1 - Optical Particle Counter (PCASP-X) down |
| DataStreams: | sgpaosC1.a0, sgpaosauxC1.a0 |
| Description: | The AOS Optical Particle Spectrometer (PCASP-X sizing probe) was down during these periods. This lowers the laser reference voltage and results in inaccurate sizing. |
| Measurements: | sgpaosauxC1.a0:
sgpaosC1.a0:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 05/07/1999 | 1556 | 05/14/1999 | 1445 |
| Subject: | SGP/AOS/C1 - Ozone Instrument Failure |
| DataStreams: | sgpaosC1.a0, sgpaosauxC1.a0 |
| Description: | A malfunction occurred with the AOS surface ozone instrument during the period 990507 1556 GMT to 990514 1445 GMT. The instrument reported an ozone concentration of 9.91e-01 ppm (991 ppb) continuously during this time. Quality checking of the data the following week revealed that the problem began at about the time weekly maintenance check was made on Friday. The problem continued until the next weekly maintenance check was done. Site Ops was notified by the mentor of the problem on Friday, 5/14/99, and a technician was sent to inspect the system. No switches on the instrument front panel were found in the wrong position (for example, if the instrument was inadvertantly left in a calibration mode). By the time the technician arrived at the trailer, the instrument appeared to be working correctly. No explanation is given as to why these erroneous values were being generated by the ozone instrument, except that possibly it locked up with the throwing of the weekly preventative maintenance switch and this problem was not corrected until the same switch was thrown the following week. |
| Measurements: | sgpaosauxC1.a0:
sgpaosC1.a0:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 05/21/1999 | 1413 | 05/27/1999 | 1819 |
| Subject: | SGP/AOS/C1 - Invalid absorption data |
| DataStreams: | sgpaosC1.a0, sgpaosauxC1.a0 |
| Description: | During the period noted, a valve position error with the 1-um/10-um impactor switching valve occurred. The result of this error was to invalidate all switched data. The software correctly inserted missing value codes in the nephelometer data, but the PSAP light absorption photometer for some reason reported a constant value over this period. |
| Measurements: | sgpaosauxC1.a0:
sgpaosC1.a0:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 05/21/1999 | 1348 | 05/27/1999 | 1822 |
| Subject: | SGP/AOS/C1 - Incorrect absorption and scattering data |
| DataStreams: | sgpaosC1.a0 |
| Description: | The electronically switched valve that alternately switches flow through 1-um and 10-um impactors showed an error during this time period. This error invalidated all downstream data. In the raw data files, aerosol light scattering coefficients for the TSI reference and humidified nephelometers were assigned missing value codes. The aerosol light absorption coefficient was observed to stick at a constant value over this period. The problem went away after the weekly maintenance was performed, although nothing specific was done to the valve. The flipping of the maintenance switch appears to have solved the problem. |
| Measurements: | sgpaosC1.a0:
|