MODEL 54eA | SECTION 13.0 |
| CALIBRATION - pH |
13.2AUTOMATIC TWO-POINT CALIBRATION
1.Be sure the pH feature has been enabled. See Section 5.8.
2.Obtain two buffer solutions. Ideally the buffer pH values should bracket the range of pH values to be meas- ured.
3.Remove the sensor from the process liquid. If the process and buffer temperatures are appreciably different, place the sensor in a container of tap water at the buffer temperature. Do not start the calibration until the sen- sor has reached the buffer temperature. Thirty minutes is usually adequate.
Adjust temperature Calibrate pH Output trim
4.From the main display, press any key to obtain the main menu. With the cursor on "Calibrate" press Enter (F4).
NOTE
If Hold was enabled in Section 5.6, the hold screen will appear. To activate hold, refer to Section 5.6, step 11.
5.Press the ê key three times to move the cursor to "Calibrate pH". Press Enter (F4).
ExitEnter
6. Press Enter (F4).
Buffer calibration Standardize pH pH slope
ExitEnter
4.02pH
Autocal buffer 1
7.Rinse the sensor with water and place it in buffer 1. Be sure the glass bulb and reference junction are completely submerged. Swirl the sensor. Press Cont (F3). "Wait" flashes until the reading stabi- lizes.
If the controller appears locked, the reading is not stable enough.
Abort ContInvestigate and correct the cause of the noise or drift (see Section 14.8). Alternatively, change the stability limits (see Section 5.8) and repeat the calibration.
4.02pH
Buf1done: 4.00 @25°C
8.The screen at left appears once the reading is stable. Use the é or ê key to change the reading to the nominal pH of the buffer. The nominal pH is the pH of the buffer at 25°C. Press Cont (F3).
Abort Cont
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