pH Calibration of the Ultrameter 6PFCE:

Posted by 23 Mar, 2014


*Note: This procedure applies to the Ultrameter, PoolPro, TechPro, and D-6 Dialysate meter.

IMPORTANT: Always “zero” your Ultrameter II with a pH 7 buffer solution

before adjusting the gain with acid or base buffers, i.e., 4 and/or 10, etc.

a. pH Zero Calibration (6PFCE)

1. Rinse sensor well and cell cup 3 times with 7 buffer solution.

2. Refill both sensor well and cell cup with 7 buffer solution.

3. Press






to verify the pH calibration. If the display shows 7.00, skip the pH

Zero Calibration and proceed to pH Gain Calibration.

4. Press

CAL key






to enter calibration mode. “CAL”, “BUFFER” and “7” will appear on the display.









Displayed value will be the uncalibrated sensor.

NOTES: If a wrong buffer is added (outside of 6-8 pH),“7” and “BUFFER

will flash, and the Ultrameter II will not adjust.

The uncalibrated pH value displayed in step 4 will assist in determining

the accuracy of the pH sensor. If the pH reading is above 8 with pH 7

buffer solution, the sensor well needs additional rinsing or the pH sensor

is defective and needs to be replaced.

5. Press












until the display reads 7.00.

NOTE: Attempted calibration of >1 pH point from factory calibration will

cause “FAC” to appear. This indicates the need for sensor replacement

or fresh buffer solution. The “FAC” internal electronic calibration is not intended to

replace calibration with pH buffers. It assumes an ideal pH sensor. Each “FAC”

indicates a factory setting for that calibration step (i.e., 7, acid, base).

You may press

CAL key






to accept the preset factory value, or you may

reduce your variation from factory setting by pressing












6. Press to accept the new value. The pH Zero Calibration

is now complete. You may continue with pH Gain Calibration or

exit by pressing any measurement key.

b. pH Gain Calibration (6PFCE)

IMPORTANT: Always calibrate or verify your Ultrameter II with a pH 7

buffer solution before adjusting the gain with acid or base buffers, i.e.,

4 and/or 10, etc. Either acid or base solution can be used for the 2nd

point “Gain” calibration and then the opposite for the 3rd point. The

display will verify that a buffer is in the sensor well by displaying either

Acd” or “bAS”.

1. The pH calibration mode is initiated by either completion of the

pH Zero Calibration, or verifying 7 buffer and pressing the

CAL key






key twice while in pH measurement mode.

2. At this point the “CAL”, “BUFFER” and “Acd” or “bAS

will be displayed (see Figures 7 and 8).



NOTE: If the “Acd” and “bAS” indicators are blinking, it indicates

an error and needs either an acid or base solution present in the sensor


3. Rinse sensor well 3 times with acid or base buffer solution.

4. Refill sensor well again with same buffer solution.

5. Press












until the display agrees with the buffer value.

6. Press

CAL key






to accept the 2nd point of calibration. Now the

display indicates the next type of buffer to be used.

Single point Gain Calibration is complete. You may continue for the 3rd

point of Calibration (2nd Gain) or exit by pressing any measurement key.

Exiting causes the value accepted for the buffer to be used for both acid

and base measurements.

To continue with 3rd point calibration, use basic buffer if acidic buffer

was used in the 2nd point, or vice-versa. Again, match the display to the

known buffer value as in step 2 and continue with the following steps:

7. Repeat steps 3 through 6 using opposite buffer solution.

8. Press

CAL key






to accept 3rd point of calibration, which completes the Calibration procedure.

Fill sensor well with Sensor Storage Solution and replace protective cap.

You can find technical advice and videos, the calibration solutions you need, and reliable Myron L meters
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