YSI 550A - Manual (Page 11)

YSI 550A
Y S I
Environmental
Page 7
6. CAL will now display in the lower left corner of the screen, the calibration value in the lower right
corner and the current DO reading (before calibration) will be the main display. Once the current
DO reading is stable, press the ENTER button.
7.
The LCD will prompt you to enter the approximate salinity of the water you are about to analyze.
You can enter any number from 0 to 70 parts per thousand (PPT) of salinity. Use the arrow keys to
increase or decrease the salinity setting. When the correct salinity appears on the LCD, press the
ENTER key. The instrument will return to normal operation.
CALIBRATION IN MG/L
1.
Power the instrument on and allow readings to stabilize. This may take 5 to 15 minutes, depending
on the age of the instrument and condition of the probe.
2.
Place the probe in a solution with a known mg/L reading. Continuously stir or move the probe
through the sample at a rate of at least 1/2 foot per second (16cm per second) during the entire
calibration process.
3.
Press and release both the UP ARROW and DOWN ARROW keys at the same time to enter the
calibration menu.
4.
Press the Mode key until “mg/L” is displayed on the right side of the screen for oxygen units.
Press ENTER.
5.
CAL will now display in the lower left corner of the screen and the current DO reading (before
calibration) will be on the main display. Once the current DO reading is stable, use the up and down
arrow keys to select the mg/L value of the known solution, then press the ENTER button.
6.
The LCD will prompt you to enter the approximate salinity of the water you are about to analyze.
Enter any number from 0 to 70 parts per thousand (PPT) of salinity. Use the arrow keys to increase or
decrease the salinity setting. When the correct salinity appears on the, press the ENTER key. The
instrument will return to normal operation.
SALINITY COMPENSATION CALIBRATION
1. Press the Mode key until salinity calibration is displayed on the screen.
2. Use the UP ARROW and DOWN ARROW keys to adjust the salinity value to that of the
samples you will be measuring, 0-70 ppt.
3. Press the ENTER key to save the calibration.
4. Press Mode to return to dissolved oxygen measurement