YSI ProODO User Manual

Page 13

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%

0.62525%

1.275%

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%