COD Digestion Reactor
A dry heating block that holds sealed glass tubes at 150 °C for two hours so that potassium dichromate can oxidise the organic matter in water and wastewater samples. It is the heart of the closed reflux COD test.
- Environmental testing laboratories
- Municipal water and wastewater utilities
- Chemical and pharmaceutical effluent treatment
- Food and beverage processing
- Textile, pulp and paper, and distilleries
COD digester calibration procedures
Block temperature check
Confirms that the COD reactor block holds 150 °C in every well used for digestion.
Open procedureCOD standard (KHP) recovery
Digests a potassium hydrogen phthalate (KHP) standard of known theoretical COD and checks that the measured COD is recovered within limits.
Open procedureInstrument qualification (DQ · IQ · OQ · PQ)
- 01
Design qualification (DQ)
Define the tube size, number of wells, temperature range (at least 150 °C, with options for 100–120 °C digestions) and timer features needed for the lab's COD and nutrient tests.
- 02
Installation qualification (IQ)
Record model and serial numbers, install on a level, heat-resistant bench away from flammables, and check the power supply and safety cover.
- 03
Operational qualification (OQ)
Verify block temperature at 150 °C in several wells with a calibrated thermometer, and verify the timer. Typical limits are 150 ± 2 °C.
- 04
Performance qualification (PQ)
Digest replicate KHP standards and real samples and show recoveries and repeatability meet the method's quality control limits.
Keep every COD digester in control: usage logs, calibration and maintenance schedules, and automatic blocking of overdue instruments.