YSI 6000UPG - Manual (Page 152)

E-1
APPENDIX E
APPLICATION NOTE
SENSOR DRIFT COMPENSATION WITH THE 6000 UPG
The following application note is designed to facilitate the use of the sensor drift software included
in the PC6000 package by providing the user with a specific example. The use of this function is
generalized in Section 5.4 of the 6000
UPG
manual.
Situation
After laboratory calibration, a user deployed their 6000 UPG in a readily-accessible stream on
10/14/92 with the instrument set to log data to memory at 15 minute intervals. The study was named
SRUN7. The instrument was left in place for approximately 2 weeks and during this time period,
the user visited the site 3 times, took a water sample in a sealed bottle, and, on returning to the
laboratory, measured the dissolved oxygen and pH with recently-calibrated instruments. The user
also collected a water sample when the instrument was retrieved (10/26/92) and measured dissolved
oxygen and pH in the laboratory. The following records were kept.
Laboratory Measurements
Date Time DO (mg/L) pH
10/17/92 8:00 5.40 7.62
10/29/92 8:00 7.50 7.63
10/23/92 10:00 7.30 7.58
10/26/92 8:15 6.32 7.60
The user now has everything required to compensate the DO and pH readings for field drift:
•
The data file logged to sonde memory.
•
The correct DO and pH readings at various times during the study based on grab samples of
water which were analyzed with recently-calibrated laboratory instruments.
•
PC6000 software for retrieval and manipulation of the data from the sonde memory.