Online COD analyser
Chemical oxygen demand measured continuously at the outlet, without reagents
Chemical oxygen demand (COD) is the oxygen needed to oxidise the organic matter in effluent, and one of the parameters every OCEMS station reports. In the laboratory it takes about two hours of digestion with dichromate. At the outlet, our probe reads it continuously from the effluent's UV–visible absorption spectrum, with no reagents to buy or dispose of.
- SYZE-OCEMS-8P
- One of 8 parameters as standard
- CPCB
- HSPCB
- PPCB
At a glance
Supplied as part of the SYZE-OCEMS-8P, with all eight parameters as standard.
- Parameter
- COD, chemical oxygen demand
- Range
- 0–1000 mg/L, set to your consented limits
- Method
- UV–visible absorption spectroscopy
- Instrument
- The multi-parameter optical probe of the SYZE-OCEMS-8P, which also gives the other optical parameters
- Reagents
- None
- Output
- RS485 Modbus to the SYZE data logger
- Reported to
- CPCB, HSPCB, PPCB and PHED
Keeping COD readings right
- Set against your laboratory
- At commissioning the reading is matched to laboratory COD results for your outlet, because every effluent absorbs light a little differently.
- Clean optics
- The probe's measuring window is cleaned on a schedule; fouling is the most common cause of drift.
- Checked regularly
- A grab sample tested in the laboratory is compared with the online value for the same time.
- A silent probe shows as silent
- If the probe stops responding, the panel records zero and flags it - never the last good value.
Questions
Why does the online COD differ from our laboratory COD?
Some difference is normal: the online value is continuous, a sample is one moment. A lasting difference means the correlation or the cleaning needs attention, and we recheck it against your laboratory.
Does COD need its own instrument?
No. COD comes from the same optical probe as BOD, TSS, TOC, turbidity and temperature.
The analyser and the other parameters
- Online water quality analyser (8 parameters)Our main product: eight parameters as standard, made in India
- BOD analyserContinuous BOD at the outlet, when the laboratory test takes three days
- TSS analyserTotal suspended solids measured continuously, by optical absorption and scatter
- pH analyserpH at the outlet on its own port, with automatic temperature compensation
- TOC analyserTotal organic carbon from the same UV–visible spectrum, as standard
- Turbidity analyserHow clear the effluent is, measured continuously as scattered light
- TemperatureA PT100 sensor built into the optical probe
- FlowFlow turns concentrations into loads, and every OCEMS station reports it
Further reading
See it working
Send us the COD limit in your consent and we will set the analyser's range.