Xylem YSI Pro20 User manual

Pro20 / Pro20i
Quick Start Guide
Item #605645
This Pocket Guide is meant to serve as a quick reference in calibrating and operating the
Pro20/Pro20i. It is not intended to replace the information found in the User Manual.
Installing the DO Membrane
1. Prepare the O2probe solution according to the instructions on the bottle. After
mixing, allow the solution to sit for 1 hour. This will help prevent air bubbles
from later developing under the membrane.
2. Remove, and discard the red protective cap or used membrane from the sensor.
3. Thoroughly rinse the sensor tip with distilled or deionized water.
4. Fill a new membrane cap with probe solution. Avoid touching the membrane
portion of the cap.
5. Thread the membrane cap onto the sensor, moderately tight. A small amount of
electrolyte will overflow.
6. Screw the probe sensor guard on moderately tight.
Setting Sensor & Membrane Type
The instrument will step you through an initial configuration when powered on for the
first time. This allows you to set the language, sensor, and membrane options. Use the
up or down arrow keys to highlight the appropriate language, sensor, and membrane,
then press enter to confirm. To change the sensor or membrane type after the initial
configuration, press the Menu key.
The instrument’s Sensor Type must be configured for the sensor installed.
Failure to do this may result in damage not covered under warranty.
Barometer Calibration
The barometer reading must be accurate to ensure accurate DO% calibrations and DO
readings.
If your barometer requires an adjustment:
1. Determine your local barometric pressure (BP) in mmHg from a mercury
barometer, an independent laboratory, or from a local weather service. If the
BP reading has been corrected to sea level, use the following equation to
determine the true BP in mmHg for your altitude.
True BP = (Corrected BP in mmHg) – {2.5 * (Local Altitude in feet/100)}

DO Calibration
The Pro20/Pro20i can be calibrated in % saturation, mg/L, or ppm. Calibration of any
option (%, mg/L, or ppm) will automatically calibrate the others. The Pro20/Pro20i can
be calibrated with the press of one key when One Touch Cal is enabled in the System
Setup menu.
The following procedure outlines the % saturation calibration option with and without
One Touch Cal enabled.
1. Moisten the sponge in the cal/transport sleeve with a small amount of water
and install it on the probe. The cal/transport sleeve ensures venting to the
atmosphere. Make sure the DO and temperature sensors are not immersed
in the water.
2. Turn the instrument on. If using a polarographic sensor, wait 10 minutes for the
DO sensor to stabilize. Galvanic sensors do not require a warm up time.
3. Ensure the barometer reading and salinity correction values along the bottom of
the screen are accurate.
4. Press and hold the Cal key for three seconds.
5. If One Touch Cal is enabled, the instrument will indicate Calibrating %DO on
the display and automatically calibrate the sensor to the barometer reading and
salinity correction value.
6. If One Touch Cal is not enabled, highlight %or %Local and press Enter. The
Pro20/Pro20i will display the current DO% and temperature readings along
with the % calibration value. Wait at least 3 seconds, then, once the DO% and
temperature readings are stable, press Enter to complete the calibration.
7. Calibration Successful will display for a few seconds to indicate a successful
calibration and then the instrument will return to the run screen.
8. If the calibration is unsuccessful, an error message will display on the screen.
Press the Cal key to exit the error message and return to the run screen.
Salinity Compensation Calibration
The Pro20/Pro20i uses an inputted salinity value in ppt (parts per thousand) to
compensate dissolved oxygen mg/L values.
2. From the run screen, use the up or down arrow keys to highlight the barometer
box then press enter.
3. Use the up or down arrow keys to adjust the barometer reading to the local,
true barometric pressure.
4. Press enter to confirm and save the barometer adjustment.

To adjust the salinity compensation value:.
1. Use the up or down arrow keys to highlight the salinity box on the run screen,
then press enter.
2. Use the up or down arrow keys to adjust the salinity compensation value to the
salinity of the water you are testing.
3. Press enter to confirm and to save the new salinity compensation value.
Taking Measurements
The Pro20/Pro20i can be calibrated in %saturation, mg/L, or ppm. Calibration of any
option (%, mg/L, or ppm) will automatically calibrate the others. The Pro20/Pro20i can
be calibrated with the press of one key when One Touch Cal is enabled in the System
Setup menu.
The following procedure outlines the % saturation calibration option with and without
One Touch Cal enabled.
1. Turn the instrument on and wait 5-15 minutes if using a polarographic sensor.
2. To take readings, insert the probe into the sample. Move the probe in the
sample at a rate of at least 6 inches per second until the readings stabilize.
3. Highlight Save and press Enter to store the reading. The instrument will
confirm that the reading was successfully saved.
Visit YSI.com/Pro20 or YSI.com/Pro20i to
find the User Manual, specs, and accessories.
Item# 605645 Dwg# 605645
January 2020 Rev E
1725 Brannum Lane
Yellow Springs, OH 45387
[phone], [phone]
[email protected]
Contact Information

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