Hach 25M3A2000-100 Manual De Instrucciones página 12

9. Push OK.
10. Proceed to the calibration with a reference solution or process sample.
4.4.4 Calibration with the process sample
The sensor can remain in the process sample, or a portion of the process sample can be removed
for calibration. The reference value must be determined with a secondary verification instrument.
Note: If the sensor is calibrated for the first time, be sure to complete the zero calibration first.
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 Calibration (or 1-point value calibration).
Note: Use the Measurement type setting to change the parameter that is calibrated.
4. 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.
5. With the sensor in the process sample, push OK.
The measured value is shown.
6. Wait for the value to stabilize and push OK.
Note: The screen may advance to the next step automatically.
7. Measure the conductivity (or other parameter) value with a secondary verification instrument. Use
the arrow keys to enter the measured value and push OK.
8. Review the calibration result:
• "The calibration was successfully completed."—The sensor is calibrated and ready to measure
samples. The slope and/or offset values are shown.
• "The calibration failed." —The calibration slope or offset is outside of accepted limits. Repeat
the calibration with fresh reference solutions. Clean the sensor if necessary.
9. Push OK to continue.
10. 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.
4.4.5 Temperature calibration
The instrument is calibrated at the factory for accurate temperature measurement. The temperature
can be calibrated to increase accuracy.
1. Put the sensor in a container of water.
2. Measure the temperature of the water with an accurate thermometer or independent instrument.
3. Select the main menu icon, then select Devices. A list of all of the available devices shows.
4. Select the sensor and select Device menu > Calibration.
5. Select 1-point temperature calibration (or Temperature adjustment).
6. Enter the exact temperature value and push OK.
7. Return the sensor to the process.
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