Evoqua United States - Canada - EN

How to Calibrate the DEPOLOX® 700 M Controller

The DEPOLOX® 700 M Controller is applicable for the measurement of chlorine, pH, ORP, temperature and conductivity.


Chlorine Calibration

With the chlorine calibration, each chlorine sensor (free chlorine or total chlorine) must be calibrated separately.

Free Chlorine
With the calibration for free chlorine, a zero point calibration and a measuring value calibration (DPD1) must be realized. 

Zero Point Calibration

  1. Starting from the main screen, press the menu field with measuring value "Cl2 free".
  2. Select menu field "Calibration". The window "Cl2 free - Calibration" appears on the graphic display.
  3. Close the ball valve on the sample water inlet.
  4. Select the parameter "Zero".
  5. Wait until the displayed chlorine value no longer changes.
  6. Press "Apply" to set the display to "0.00".
  7. Open the ball valve on the sample water inlet.
  8. After zero point calibration, wait at least 2 minutes.

Measuring Value Calibration (DPD)

  1. Open the sample taking unit (drain) by approximately one turn and extract a specimen of the sample water.
  2. Determine the content of free chlorine in the sample using a photometer.
  3. Select the parameter "DPD".
  4. Use the input field to enter the determined value.
  5. Confirm the entry with the Enter key.

This concludes the calibration for free chlorine.

Total Chlorine Calibration

  1. Open the drain by approximately one turn and collect a sample water.
  2. Determine the total chlorine content (DPD3) with a photometer or other grab sample test device.
  3. Starting from the main screen, press the menu field with measuring value "Cl2 total".
  4. Select the menu field "Calibration". The window "Cl2 total - Calibration" appears on the graphic display.
  5. Select the parameter "DPD".
  6. Use the input field to enter the determined value.
  7. Confirm the entry with the Enter key.

This concludes the total chlorine calibration.

Combined Chlorine

  1. Determine the values for free chlorine (DPD1) and total chlorine (DPD3) as described under "Total chlorine" step 1 or 2.
  2. Determine the value for combined chlorine: Total chlorine DPD3 minus free chlorine DPD1 = combined chlorine
  3. Starting from the main screen, press the menu field with measuring value "Cl2 combined".
  4. Select the menu field "Calibration". The window "Cl2 combined - Calibration" appears on the graphic display.
  5. Select the parameter "DPD".
  6. Use the input field to enter the determined value as described under "Total chlorine".
  7. Confirm the entry with the Enter key.

This concludes the combined chlorine calibration.


PH Calibration

  1. Starting from the main screen, press the menu field with measuring value "pH".
  2. Select the menu field "Calibration". The window "pH - Calibration" appears on the graphic display.
  3. Select the "pH 7" parameter.
  4. Place the beaker into the bottom clip and fill with the buffer solution "pH 7.00" or clamp the bag with the buffer solution "pH 7.00" into the bottom clip.
  5. Close the sample water inlet and outlet (for pressurized version of the flow cell only) and open the sample taking unit (drain) briefly. Close the sample taking unit (drain) once more.
  6. Pull or unscrew the pH sensor from the cover of the cell body of the flow cell.
  7. Dip the pH sensor through the top clip at least 2 cm (1 inch) deep into the buffer solution and move slightly until the indicated pH value remains constant.
  8. Use the input field to enter the value of the buffer solution to be calibrated.
  9. Confirm the entry with the Enter key.
  10. Remove the buffer solution "pH 7.00" from the bottom clip.
  11. Wash the sensor in distilled water to prevent carryover of the buffer solution.
  12. Select the parameter "pH X".
  13. If the sample water and the pH buffer solution are at different temperatures, the temperature value of the buffer solution should be entered under "Calibrate at"
  14. The value is deleted again when the menu "pH X" is closed.
  15. Place the beaker into the bottom clip and fill with the buffer solution "pH 4.65" or clamp a bag with the buffer solution "pH 4.65" into the bottom clip.
  16. Dip the pH sensor at least 2 cm (1 inch) deep into the buffer solution and move gently until the indicated pH value remains constant.
  17. Use the keypad to enter the value to be calibrated.
  18. Confirm the entry with the Enter key.
  19. Remove the pH sensor from the top clip.
  20. Insert or screw the pH sensor into the cover of the cell body of the flow cell.
  21. Open the sample water inlet and outlet once more (for pressurized version of the flow cell only).

This concludes the pH calibration.


ORP Calibration (REDOX)

  1. Starting from the main screen, press the menu field with measuring value "ORP".
  2. Select the menu field "Calibration". The window "ORP - Calibration" appears on the graphic display.
  3. Select the "Cal. value" parameter.
  4. Place the beaker into the bottom clip and fill with the calibration solution "478 mV" or clamp a bag with the calibration solution "478 mV" into the bottom clip.
  5. Close the sample water inlet and outlet (for pressurized version of the flow cell only) and open the sample taking unit (drain) briefly. Close the sample taking unit (drain) once more.
  6. Pull or unscrew the ORP sensor from the cover of the cell body of the flow cell.
  7. Dip the ORP sensor through the top clip at least 2 cm deep into the calibration solution and move slightly until the indicated value remains constant.
  8. Use the keypad to enter the value to be calibrated.
  9. Confirm the entry with the Enter key.
  10. Remove the ORP sensor from the top clip.
  11. Insert or screw the ORP sensor into the cover of the cell body of the flow cell.
  12. Open the sample water inlet and outlet once more (for pressurized version of the flow cell only).

This concludes the ORP calibration.


Temperature Calibration

  1. Starting from the main screen, press the menu field with measuring value "Cl2 free".
  2. Select the menu feld "Calibration". The window "Cl2 free - Calibration" appears on the graphic display.
  3. Select the parameter "Temperature".
  4. Perform comparative temperature measurement.
  5. Enter the value to be calibrated using the keypad.
  6. Confirm the entry with the Enter key.

This concludes the temperature calibration.


Conductivity Calibration

  1. Starting from the main screen, press the menu field with measuring value "Conductivity".
  2. Select the menu field "Calibration". The "Conductivity - Calibration" window appears on the graphic display.
  3. Select the parameter "Cal. value".
  4. Place the beaker into the bottom clip and fill with approx. 25 ml of the calibration solution "60.0mS/cm" or clamp a bag with calibration solution "60.0 mS/cm" into the bottom clip.
  5. Close the sample water inlet and outlet (for pressurized version of the flow cell only) and open the sample taking unit (drain) briefly. Close the sample taking unit (drain) once more.
  6. Pull or unscrew the conductivity sensor from the cover of the cell body of the flow cell.
  7. Dip the conductivity sensor through the top clip into the calibration solution to the bottom of the beaker.
  8. Pull out the conductivity sensor and rinse off with distilled water.
  9. Repeat the dipping and rinsing procedure several times.
  10. Replace the calibration solution that is in the bottom clip with a new one.
  11. Repeat the measurement. Move the conductivity sensor slightly until the displayed value remains constant.
  12. Use the keypad to enter the value to be calibrated.
  13. Confirm the entry with the Enter key.
  14. Insert or screw the conductivity sensor into the cover of the cell body of the flow cell.
  15. Open the sample water inlet and outlet once more (for pressurized version of the flow cell only).

This concludes the conductivity calibration.

Safety Tip
The above instructions are meant to be a general guideline. Always refer to the owner's manual for your specific system.