Xylem YSI ProDSS, User Manual

Page: 54 / 92

52
Calibration
Chilled Third Calibration Point
The 3-point calibration method assures maximum accuracy when the temperature of the media to be monitored
cannot be anticipated. If you must perform a chilled 3-point calibration, the following procedure requires one portion
of the high concentration calibration solution and two portions of the low concentration calibration solution.
The high concentration solution and one of the low concentration solutions should be at ambient temperature. The
other low concentration solution should be chilled to less than 10 °C (50 °F) to prior calibration point.
See “ISE calibration 3-point” on page 51 .
1. When “Ready for cal point 3” is displayed in the message area during ISE calibration, place the proper amount
of chilled 1 mg/L standard (10 mg/L for the chloride) into a clean, dry or pre-rinsed calibration cup.
2. Carefully immerse the sensor into the solution. Allow for temperature equilibration. If necessary, select
Calibration value to manually enter the standard #3 value.
3.
Once the readings are stable, select
Accept Calibration
. “Calibration successful!” will be displayed in the
message area.