YSI 6000UPG - Manual (Page 168)

H-4
Samples to Average” be set to 8. We feel that this setting will normally produce data which is
reflective of the “average” turbidity of field sites, but will not slow the response time so as to
result in any significant inconvenience to the user during calibration.
If the user wishes to view “instantaneous” turbidity events rather than the “average” turbidity at a
site, the data smoothing can be reduced by lowering the value of the “Number of Samples to
Average” or can be eliminated completely by entering a value of 1.
CAUTION: With the recommended setting of 8 in place, it is important to remember to wait at
least 32 seconds before confirming a calibration or before recording field reading in a spot
sampling application. Otherwise, the readings may be biased by the averaging until 8 samples
have been processed
Question 7: How do I manually activate the turbidity wiper on a 6026 when the
6000
UPG is sampling?
If you are using the 6000 UPG /6026 with a 610, press the “T” key to activate the wiper. If the
6000 UPG is connected to a computer (sequential lines of data are present on the screen), press the
“3” key to activate the wiper.
IMPORTANT TIP: While connected to a computer, the wiper can also be manually activated
by pressing the “3” key while in the Calibrate and Diagnostic modes. The user may be unaware
of this feature since no screen prompt to this effect is present.
Question 8: What are the things most likely to give me problems when measuring
turbidity with the 6000
UPG ?
We feel that that the 6000 UPG turbidity system has been designed to be easy to calibrate, easy to
use in both sampling and deployment applications, and troublefree in normal usage. However,
during our testing of prototype and production systems and sensors, we have observed occasional
problems in calibration and in field applications. These difficulties are likely to be experienced
only infrequently by 6000
UPG
users. In fact, most of these problems are not due to any
malfunction in the turbidity system itself, but instead occur because of contaminated calibration
solutions or the presence of bubbles on the optics of the probe. However, we have gained
experience in separating problems which can be easily solved by the user from those which
involve sensor malfunction and must be dealt with by YSI Customer Service and Product Repair.
This section is intended to pass this experience along to the user.
You might see calibration errors. This problem could be due to bubbles on the optical surface,
contamination of your 0 NTU standard, or a higher calibration standard which has not been
prepared properly or has been contaminated or diluted inadvertently. The problem could also be
due to an internal malfunction of the probe optical system. To troubleshoot the problem, do not
override the cal error , return to the Main menu and activate Discreet Sampling at a 4 second
interval in the Run mode. Remove the sonde guard and place your thumb or finger over the
optics of the probe while observing the data display. The reading should be large (either positive