YSI 556 MPS - Manual (Page 53)

Calibrate Section 6
YSI Incorporated YSI 556 MPS Page 47
5. Press Enter. The pH Entry Screen is displayed.
Figure 6.13 pH Entry Screen
6. Place the correct amount (see Table 6.1 Calibration Volumes)
of pH buffer into a clean, dry or pre-rinsed
transport/calibration cup.
NOTE: Always calibrate with buffer 7 first, regardless if
performing a 1, 2, or 3 point calibration.
WARNING: Calibration reagents may be hazardous to your
health. See Appendix D Health and Safety for more information.
NOTE: For maximum accuracy, the pH buffers you choose
should be within the same pH range as the water you are
preparing to sample.
NOTE: Before proceeding, ensure that the sensor is as dry as
possible. Ideally, rinse the pH sensor with a small amount of
buffer that can be discarded. Be certain that you avoid cross-
contamination of buffers with other solutions.
7. Carefully immerse the sensor end of the probe module into
the solution.
8. Gently rotate and/or move the probe module up and down to
remove any bubbles from the pH sensor.