Blog Details

Correct operation and maintenance of the COD online analyzer are critical to ensuring the accuracy of water quality monitoring data and the long-term stable operation of the instrument. Below is a detailed guide for operation and maintenance:

‌I. Proper Operation‌

‌Sampling Preparation‌

• • ‌Select an appropriate sampling point‌: Ensure the sampling location is away from pollution sources and in an area with relatively stable water quality.
  • ‌Use clean sampling containers‌: Avoid contamination from impurities in the containers.
  • ‌Complete sampling quickly‌: Minimize exposure of the sample to air to prevent changes in COD levels.

‌Instrument Operation‌

• • Turn on the instrument power and wait for the warm-up to complete.
  • Calibrate the instrument according to the manufacturer’s instructions to ensure measurement accuracy.
  • Set parameters such as sample volume, reaction time, etc., as needed.
  • Inject the collected sample into the sampling system, ensuring no air bubbles are present.
  • Start the measurement program; the instrument will automatically perform sampling, reaction, and measurement.
  • Record results after completion and conduct necessary data processing and analysis.

‌II. Routine Maintenance‌

‌Surface and Probe Cleaning‌

• • Regularly wipe the instrument surface and probes with a damp cloth or cotton swab to remove dust and debris.
  • Avoid corrosive cleaning agents to prevent damage.

‌Sampling Head Cleaning‌

• • Clean the sampling head periodically to prevent clogging. Recommended frequency: every 2–4 weeks (shorter intervals for poorer water quality).
  • Use appropriate cleaning agents and water flow to rinse internal and external surfaces thoroughly.

‌Pipeline and Probe Maintenance‌

• • Clean probes and pipelines regularly to remove organic/inorganic residues.
  • Use dedicated cleaning agents and tools; avoid harsh chemicals.

‌Reagent Management‌

• • Replace reagents (e.g., potassium dichromate, silver sulfate) per manufacturer guidelines and usage frequency.
  • Replace highly corrosive reagents (e.g., potassium dichromate) every 3 months.
  • Store reagents in a dry, cool area away from moisture, light, and heat.

‌Calibration and Verification‌

• • Perform zero-point and standard curve calibrations regularly.
  • Adjust calibration frequency based on usage intensity, water quality changes, and manufacturer recommendations.
  • Document calibration results, dates, and personnel after each session.

‌Pipeline Connection Checks‌

• • Inspect pipeline connections for tightness and seal integrity.
  • Address leaks or looseness promptly; replace damaged parts if needed.

‌Maintenance Records‌

• • Log details of all maintenance activities, dates, and personnel.
  • Records aid in troubleshooting and long-term instrument management.

‌Training and Guidance‌

• • Train operators periodically on principles, maintenance practices, and common troubleshooting.
  • Emphasize proper handling, safety, and error prevention.

‌Environmental Requirements‌

• • Install the instrument in a temperature- and humidity-controlled environment (use air conditioning if necessary).
  • Use a dedicated regulated power supply for stable operation.

‌III. Additional Notes‌

‌Temporary Shutdown Procedures‌

• • Flush all components with distilled water before shutdown.
  • Drain residual moisture, close inlet/outlet valves, and turn off the power.

‌Proper Usage and Storage‌

• • Follow the user manual to avoid operational errors or overuse.
  • Store the instrument in a ventilated, dry area away from direct sunlight, high temperatures, humidity, or vibrations.

By adhering to these guidelines, the COD online analyzer will deliver reliable and accurate data, supporting effective environmental protection and water resource management.