Calibration of the Ultrapen PT3 ORP Pen
The factory recommends calibrating twice a month, depending on usage. However, you should check the calibration whenever measurements are not as expected.
NOTE: If the measurement is NOT within calibration limits for any reason, “Error” will display. Check to make sure you are using a proper ORP calibration solution. If the solution is correct, clean the sensor as described im the manual under Routine Maintenance. (Reconditioning the sensor should not be necessary due to the high ionic strength of the calibration solutions.) Restart calibration.
NOTE: Small bubbles trapped in the sensor may give a false calibration. After calibration is completed, measure the ORP calibration solution again to verify correct calibration. Remember, in measurement mode you must manually correct for temperature variance from 25ºC. Example: At 25ºC, ORP2602OZ calibration solution will read 260mV; however, at 20.0ºC ORP2602OZ will read 265mV.
NOTE: If at any point during calibration, you do not submerge the sensor in solution
before the flashing slows, allow the PT3 to turn off and start over.
A. Calibration Preparation
1. Ensure the ORP sensor is clean and free of debris.
2. For maximum accuracy, pour a small amount of the calibration solution into a separate container to rinse the sensor in prior to calibration. If this is not possible, rinse the sensor in clean water prior to calibration.
Use Myron L Company 80mV Quinhydrone, 260mV Quinhydrone, or 470mV Light’s ORP Calibration Solution.
1. Thoroughly rinse the PT3 by submerging the sensor in ORP calibration rinse solution and swirling it around.
2. Push and release the push button to turn the PT3 on.
3. Push and hold the push button. The display will alternate between “CAL”, “FAC CAL”, “ºCºF TEMP”, “ModE SEL” and “ESC”.
4. Release the button when “CAL” displays. The display will indicate “CAL” and
the LED will flash rapidly.
5. While the LED flashes rapidly, dip the PT3 in ORP calibration solution so that
the sensor is completely submerged.
6. While the LED flashes slowly, the display will indicate “ [value] CAL”; swirl the
PT3 around to remove bubbles, keeping the sensor submerged.
7. If the ORP calibration is successful, the display will indicate “CAL SAVEd”, then time out.
8. Verify calibration by retesting the calibration solution.
C. Factory Calibration
When ORP calibration solution is not available, the PT3 can be returned to factory default calibration using the FAC CAL function. This will erase any stored wet calibration.
NOTE: default factory calibration resets the electronics only and does NOT take the condition of the sensor into consideration.
To return your PT3 to factory calibration:
1. Push and release the push button.
2. Push and hold the push button. The display will alternate between “CAL”, “FAC CAL”, “ºCºF TEMP”, “ModE SEL” and “ESC”.
3. Release the button when “FAC CAL” displays. The display will alternate between “PUSHnHLD” and “FAC CAL”.
4. Push and hold the push button until “SAVEd FAC” displays indicating the PT3 has been reset to its factory calibration.