Chemical Oxygen Demand (COD) is a key parameter used to assess the organic pollution load in wastewater and water samples. It plays an important role in wastewater treatment, industrial effluent monitoring, environmental testing, and laboratory analysis.
For accurate and convenient COD testing, selecting the right reagent range, digestion system, and compatible photometer or spectrophotometer is essential.
Hanna Instruments offers pre-dosed COD reagent vials in multiple measurement ranges, making routine COD testing simpler, more consistent, and convenient.
Why Use Pre-Dosed COD Reagent Vials?
COD testing involves digesting a water sample with specific reagents and measuring the resulting color change photometrically. Pre-dosed reagent vials contain the required chemistry in a ready-to-use format.
They can help:
- Reduce reagent preparation time
- Improve testing consistency
- Simplify reagent handling
- Make routine COD analysis more convenient
- Support traceability with lot and expiration information
- Adaptation of the EPA 410.4 method.
Choose the Right COD Measurement Range
Different wastewater samples can have significantly different COD concentrations. Selecting a range that matches the expected COD level helps ensure suitable measurement results.
1. HI93754A-25 — COD Low Range
Measurement Range: 0–150 mg/L as O₂
These 25-test reagent vials are designed for samples with relatively low COD concentrations.
2. HI93754B-25 — COD Medium Range
Measurement Range: 0–1500 mg/L as O₂
The medium-range vials are suitable for samples with higher COD concentrations.
3. HI93754C-25 — COD High Range
Measurement Range: 0–15,000 mg/L as O₂
Designed for samples with significantly higher COD levels, this range can be useful for certain industrial wastewater applications.
4. HI93754J-25 – COD Ultra High Range
Measurement Range: 0-60 g/L as O₂
Designed for samples with very high COD levels, this range can be useful for certain industrial and highly contaminated wastewater applications.
The HI97106 COD Portable Photometer, HI802 Iris Visible Spectrophotometer, and HI83399 Multiparameter Photometer provide convenient solutions for COD testing across field, industrial, and laboratory applications.
The HI97106 is designed for portable COD testing and features tutorial-guided testing, automatic data logging, and CAL Check™ performance verification, making it suitable for wastewater treatment, environmental monitoring, and industrial applications.
The HI802 Iris Visible Spectrophotometer delivers highly accurate measurements with its unique vial rotation technology, averaging 256 readings per measurement to improve consistency and reliability.
The HI83399 Multiparameter Photometer combines COD testing with a wide range of water quality parameters in one compact instrument. It supports multiple testing methods, making it a versatile choice for wastewater treatment plants, environmental monitoring, and laboratory applications where several water quality parameters need to be measured.
Together, these instruments provide flexible COD testing solutions—from portable field analysis to comprehensive multiparameter and laboratory testing.
Always verify the required reagent vial, method, wavelength, measurement range, and instrument compatibility before testing.
How Does COD Testing Work?
The basic COD testing process involves four key steps:
1. Select the Range
Choose the COD reagent range based on the expected concentration of the sample.
2. Add the Sample
Add the specified quantity of sample to the pre-dosed reagent vial.
3. Digest the Sample
Heat the vial using a compatible COD reactor according to the applicable method and instructions.
4. Measure the Result
After digestion and cooling, place the vial into the compatible photometer or spectrophotometer to obtain the COD reading.
For EPA-based methods, controlled heating is required during digestion. The applicable product instructions should always be followed for the correct digestion time and temperature.
The Right COD Solution for Your Application
Whether you are monitoring wastewater treatment processes, industrial effluent, environmental samples, or laboratory samples, choosing the appropriate COD range is an important part of the testing workflow.
Hanna Instruments provides COD reagent options; along with portable and laboratory instruments for convenient and efficient COD analysis.
Choose the COD reagent range that matches your expected sample concentration and confirm compatibility with your photometer, spectrophotometer, and digestion system for an efficient testing workflow.