Myron L TH1 - Manual (Page 17)

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will flash, and the TechPro 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 or 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
(ref. Troubleshooting pg. 22) 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 to accept the preset factory value, or you may
reduce your variation from factory setting by pressing or .
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 (TPH1 & TH1)
Important: Always calibrate or verify your TechPro 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
key twice while in pH measurement mode.
2. At this point the “CAL”, “BUFFER” and “Acd” or “bAS”
annunciators will be displayed (see Figures 4 and 5).
Figure 4
BUFFER
pH
CAL
Figure 5
pH
BUFFER
CAL