YSI ProODO - Manual (Page 13)

16 17
Local DO is ideal for EU compliance. When Local DO is enabled, an L will
appear next to DO% on the run screen. DO mg/L readings are unaffected by the
selection of DO Local.
LDS (Last Digit Suppression) rounds the DO value to the nearest tenth; i.e. 8.27
mg/L becomes 8.3 mg/L. Highlight LDS and press enter to activate or deactivate
LDS. Some users may not want to read out to the hundredths place since the DO
mg/L accuracy spec is to the tenths place.
Sensor Cap allows you to view and enter information specific to the sensor
cap installed on the probe. Highlight Sensor Cap and press enter to view the
sensor cap’s Serial #, Temperature Coefficient, and Sensor Cap Coefficients.
This information is programmed into the sensor at the factory and sent to the
instrument when the cable is connected. Since the Temperature Coefficient is
programmed into the sensor at the factory, it should not be modified unless
instructed by YSI Technical Support.
The Sensor Cap Coefficients need to be updated when the sensor cap is replaced.
The sensor cap should be replaced about once per year. See the Dissolved
Oxygen Sensor Maintenance section of this manual or the instruction sheet
included with replacement sensor cap for instructions on updating the Sensor
Cap Coefficients. When updating the Coefficients, the sensor cap serial # will
be updated automatically based on your entries.
DISPLAY - DISSOLVED OXYGEN
Press Probe , highlight Display and press enter. Highlight DO and press
enter. Note, you will not be able to display dissolved oxygen unless it is Enabled
in the DO Setup menu first, see previous section.
DO % will show DO readings in a percent scale from 0
to 500%.
DO mg/L will show DO readings in milligrams per liter
(equivalent to ppm) on a scale from 0 to 50 mg/L.
DO ppm will show DO readings in parts per million (equivalent to mg/L) on a
scale from 0 to 50 ppm.
All units can be displayed simultaneously on the screen. Highlight the desired
unit(s) and press enter to select. A check mark in the box next to the unit will
indicate that it is enabled.
AUTO STABLE - DISSOLVED OXYGEN
Press Probe , highlight Auto Stable and press enter. Highlight DO and press
enter.
Auto Stable indicates when a reading is stable.
Highlight Enabled and/or Audio Enabled
(instrument will beep when the stability is
achieved) and press enter to confirm. When
Auto Stable is enabled, AS will blink next to the
parameter until it is stable. Once the parameter
is stable, AS will stop blinking.
The Auto Stable Sensitivity can be decreased or
increased. Highlight Sensitivity and use the left and right arrow keys to slide
the bar. The more sensitive you make it (larger black bar) the harder it is to
achieve stability in a changing environment.
The Auto Stable system works by examining the previous 5 readings, computing
the percent change in the data and comparing that change against a % threshold
value. The % threshold value is determined by the Sensitivity bar setting. The
following chart can be used as a guide when setting the Sensitivity bar.
Sensitivity selected by User % Data Variance Threshold
100 - Most Sensitive, Sensitivity
bar is set to the far right
0.05%
75 0.62525%
50 1.275%
25 1.8875%
0 - Least Sensitive, Sensitivity
bar is set to the far left
2.5%
Example:
The instrument obtained the following data:
Reading #1 95.5 DO%
Reading #2 95.7 DO%
Reading #3 95.8 DO%
Reading #4 96.1 DO%
Reading #5 95.3 DO%