Emerson Process Management 53eA Manual De Usuario

4.02

pH

Buf1done: 

4.00 

@25°C

Abort

Cont

4.02

pH

Autocal buffer 1

Abort

Cont

Adjust temperature

Calibrate pH

Output trim

Exit

Enter

Buffer calibration

Standardize pH
pH slope

Exit

Enter

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. 

4.  From the main display, press any key to obtain the main menu.

With the cursor on "Calibrate" press Enter (F4).

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).

6.  Press Enter (F4).

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.
Investigate 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.  

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).