Hach Polymetron pH/ORP Manual Del Usuario página 13

1. Put the sensor in the first reference solution (a buffer or sample of known value). Make sure that
the sensor portion of the probe is fully immersed in the liquid. Stir the sensor to remove any
bubbles.
Note: The sensor can remain in the process sample, or a portion of the process sample can be removed for
calibration.
2. Select the main menu icon, then select Devices. A list of all of the available devices shows.
3. Select the sensor and select Device menu > Calibration.
4. Note:
Select 1-point value calibration.
5. Select the option for the output signal during calibration:
Option Description
Active The instrument sends the current measured output value during the calibration procedure.
Hold The sensor output value is held at the current measured value during the calibration procedure.
Transfer A preset output value is sent during calibration. Refer to the controller user manual to change the
preset value.
6. With the sensor in the reference solution or sample, push OK.
The measured value is shown.
7. Wait for the value to stabilize and push OK.
Note: The screen may advance to the next step automatically.
8. If a sample is used for calibration, measure the ORP value of the sample with a secondary
verification instrument. Enter the measured value, then push OK.
9. If a reference solution is used for calibration, enter the ORP value marked on the bottle. Push OK.
10. Review the calibration results:
• "Calibration:passed"—The sensor is calibrated and ready to measure samples. The slope
and/or offset values are shown.
• "Calibration failed."—The calibration slope or offset is outside of acceptable limits. Repeat the
calibration with fresh reference solutions. Clean the sensor if necessary.
11. Push OK.
12. Return the sensor to the process and push OK.
The output signal returns to the active state and the measured sample value is shown on the
measurement screen.
4.3.6 Manual calibration (pH sensors only)
This option allows a manual update of the slope and offset values. The sensor does not need to be
removed from the process.
1. Select the main menu icon, then select Devices. A list of all of the available devices shows.
2. Select the sensor and select Device menu > Calibration.
3. Select Manual.
4. The measured calibration slope is displayed in mV/pH. Use the arrow keys to adjust the value,
then push OK.
5. The calibration offset is displayed in mV. Use the arrow keys to adjust the value, then push OK.
Note: To calculate the mV value, multiply the required pH offset value by the slope value.
6. Review the calibration results:
• "Calibration:passed"—The sensor is calibrated and ready to measure samples. The slope
and/or offset values are shown.
• "Calibration failed."—The calibration slope or offset is outside of acceptable limits.
7. Push OK.
8. Return the sensor to the process and push OK.
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