Start Date | Start Time | End Date | End Time | Data Quality Metric |
---|---|---|---|---|
12/03/1993 | 0000 | 06/30/1994 | 1714 | Suspect |
Subject: | SGP/EBBR/E4 - Pressure |
DataStreams: | sgp30ebbrE4.b1, sgp15ebbrE4.b1, sgp5ebbrE4.b1 |
Description: | Damage to some pressure sensors as a result, apparently, of high battery voltage, caused pressure readings to vary significantly at a few EBBRs for several months. I am being intentionally vague in making that statement as there are DQRs and at least one PIF that cover those cases, except for the situation at E4, Plevna, KS. Some time ago I had the suspect pressure sensors replaced and "repaired". Unfortunately, the repairs were insufficient, as we found out by using Plevna as a guinea pig for the "repaired" sensors to see if they were working. It turns out that the three repaired sensors S/N 6500, 6504, and 6509 were better, but still experienced fluctuations in output that followed battery voltage level as the battery was charged by the solar panel during the daylight hours. The fluctuations look like long-term spikes, positive or negative at different times, and lasted from one to several hours. The fluctuations had minimal impact on adjustments to computed values from the EBBR. Pressure data from Plevna for the period listed above should not be used for absolute values. That is why I marked "questionable", in the data labelling section, but this applies only to the pressure data itself. The following documents the use of pressure sensors at Plevna: 1) The original sensor, S/N 6509 was removed for repair on 1/13/94 and replaced with the "repaired" S/N 6500. 2) S/N 6500 was removed for repair on 2/10/94 and replaced with the "repaired" S/N 6504. 3) S/N 6504 was removed on 3/24/94 and replaced with "repaired" (2nd time) S/N 6500. 4) S/N 6500 was removed on 5/5/94 and replaced with "repaired" (2nd time) S/N 6504. 5) S/N 6504 was removed on 5/19/94 and replaced with "repaired" S/N 6509. 6) S/N 6509 was removed on 6/30/94 and replaced with a new sensor, S/N 6579. Sensors 6500, 6504, and 6509 have been thrown away, as the manufacturer appears to be incapable of repairing them completely. Rather than waste more money in trying to have them repaired, I ordered three new pressure sensors, of which S/N 6579 is one. Thus, we now have two new sensors as spares. |
Suggestions: | |
Measurements: | sgp30ebbrE4.b1: more
sgp5ebbrE4.b1: more sgp15ebbrE4.b1: more |