Instruction manual

82
MODEL XMT-P pH/ORP SECTION 9.0
CALIBRATION — pH
9.2 PROCEDURE — AUTO CALIBRATION
1. Obtain two buffer solutions. Ideally, the buffer values should bracket the range of pH values to be measured.
2. Remove the pH sensor from the process liquid. If the process and buffer temperatures are appreciably differ-
ent, place the sensor in a container of tap water at the buffer temperature. Do not start the calibration until the
sensor has reached the buffer temperature. Thirty minutes is usually adequate.
3. Press MENU. The main menu appears. Choose Calibrate.
4. Choose pH.
5. Choose BufferCal.
6. Choose Auto.
7. To continue with the calibration, choose Buffer1.Then go to step 8. To
change stability criteria, choose Setup and go to step 19.
8. Rinse the sensor with water and place it in buffer 1. Be sure the glass
bulb and the reference junction are completely submerged. Swirl the
sensor.
9. The screen at left is displayed with “Wait” flashing until the reading is
stable. The default stability setting is <0.02 pH change in 10 sec. To
change the stability criteria, go to step 19. When the reading is stable,
the screen in step 10 appears.
10. The top line shows the actual reading. The transmitter also identifies the
buffer and displays the nominal buffer value (buffer pH at 25°C). If the
displayed value is not correct, press é or
ê
to display the correct
value. The nominal value will change, for example from 7.01 to 6.86 pH.
Press ENTER to store.
11. The screen at left appears momentarily.
12. The screen at left appears. Remove the sensor from Buffer 1, rinse it
with water, and place it in Buffer 2. Be sure the glass bulb and the ref-
erence junction are completely submerged. Swirl the sensor. Choose
Buffer2.
13. The screen at left is displayed with “Wait” flashing until the reading is
stable. When the reading is stable, the screen in step 14 appears.
Calibrate Hold
Program
Display
Cal?
pH Temp
BufferCal?
Auto Manual
AutoCal? Setup
Buffer1 Buffer2
AutoCal? Setup
Buffer1 Buffer2
pH Standardize
Slope BufferCal
Live 7.00pH
AutoBuf1 Wait
Live 7.00pH
AutoBuf1 7.01pH
Live 10.01pH
AutoBuf2 Wait
Cal in progess.
Please wait.