YSI 5200 - Manual (Page 71)

YSI Incorporated 69 5200 Recirculating System Monitor
one-point calibration. The procedure for this calibration is the same as for a 2-point
calibration, but the software will prompt you to select only one pH buffer.
Ö Select the 2-point option to calibrate the pH sensor using two calibration standards. Use
two standards that cover the pH range of your samples. For example, if the pH of a pond is
known to vary between 5.5 and 7, perform a two-point calibration with pH 7 and pH 4
buffers.
3. The pH Entry screen is displayed, along with a message on the bottom line of the screen.
C a l i b r a t i o n
P a s s ( 1 )
NOTE: For 2-Point calibration, the display will notify you that this is Pass(1).
p H 7 . 3 4 T = 2 5 . 5 ° C
W a i t t i l S t a b l e
4. Place the correct amount (see Table 6-1 Calibration Volumes) of pH buffer into a clean, dry or
pre-rinsed calibration/storage cup.
WARNING: Calibration reagents may be hazardous to your health. See Section 18 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.
5. Carefully immerse the sensor end of the probe module into the solution.
6. Gently rotate and/or move the probe module up and down to remove any bubbles from the
outside of the pH sensor.
NOTE: The sensors must be completely immersed. Using the recommended volumes from Table
6-1 Calibration Volumes, should ensure that the sensors are covered.
7. Screw the calibration/storage cup on the threaded end of the probe module and securely tighten.
NOTE: Do not over tighten as this could cause damage to the threaded portions.
8. Allow at least one minute for temperature equilibration before proceeding.
9. Observe the pH and Temperature readings. When the readings show no significant change for
approximately 30 seconds, press the Enter [  ] key.
p H 7 . 3 4 T = 2 5 . 5 ° C
U s e r V a l 0 8 . 2 6
10. Enter the value of the pH standard at the current temperature.
NOTE: pH vs. temperature values are printed on the labels of all YSI pH buffers.
p H 7 . 3 4 T = 2 5 . 5 ° C
U s e r V a l 0 7 . 0 4
11. Skip to step 14 if you are performing a One-Point calibration.