Emerson Rosemount5081, Инструкция по эксплуатации, Страница: 59 / 152

1. Place the sensor in a solution of 5% sodium sulfite (Na
2
SO
3
) in water. Ensure that air
bubbles are not trapped against the membrane.
2. Go to the main display; press DIAG and then NEXT .
The SENSOR CUR prompt appears.
3. Press ENTER to view the sensor current. Make sure the sensor reaches its zero
current.
This may require several hours. Do not start the zero routine until the sensor has
been in zero solution for at least two hours.
4. Press CAL on the IRC.
The SENSOR 0 prompt appears.
5. Press ENTER .
The screen shows the appropriate value correlating to the zero value. The screen
shows 0.02. The reading must be below 0.02 ppm for the zero calibration to be
accepted.
6. To change the zero limit, use the editing keys and then press ENTER .
The TIME DELAY message appears and remains until the zero current is below the
concentration limit. If the current is already below the limit, TIME DELAY will not
appear.
7. To bypass the time delay, press ENTER .
When the procedure is complete, 0 DONE appears.
8. Press EXIT .
9. Press RESET to return to the main display.
7.4.3 Air calibration procedure (dissolved oxygen)
1. Remove the sensor from the process liquid. Use a soft tissue and a wash bottle to
clean the membrane. Dry it by blotting.
The membrane must be completely dry during air calibration.
2. Pour some water into a beaker and suspend the sensor with the membrane
approximately 1/2 in. (approximately 1 cm) above the water surface.
Keep the sensor out of direct sunlight.
3. Monitor the dissolved oxygen and temperature reading. Once the readings are
relatively stable, begin the calibration.
It may take 10 - 15 minutes for the sensor reading in the air to stabilize.
4. Press CAL on the IRC.
5. Press NEXT .
Measurements
Instruction Manual 49