E+H TOC COD SAC Analyzer Selection Guide

E+H TOC, COD and SAC Analyzers: Organic Load Monitoring Solutions

TOC, COD and SAC analyzers evaluate the organic load in surface water, municipal wastewater and industrial wastewater. By measuring total organic carbon (TOC), chemical oxygen demand (COD) and spectral absorption coefficient (SAC), precise water quality monitoring is achieved. Measurement at the outlet ensures compliant discharge, while measurement at the inlet helps avoid peak loads and optimize process control.

How to Choose Sum Parameter Products

High-Precision Analysis Scenarios

When high-precision analysis is required, TOC and COD analyzers can provide "true" TOC and COD values, meeting strict regulatory requirements.

• Comply with limit values specified by water authorities
• Calculate the treatment capacity of wastewater treatment plants
• Ensure industrial discharge charging according to the polluter-pays principle

Economical Monitoring Scenarios

Choose SAC probes for surface water and river water monitoring. In municipal wastewater treatment plants without significant fluctuations, SAC probes are also the correct choice for economically measuring COD and TOC equivalents.

Technical Principles and Measurement Methods

Potassium Dichromate Method COD Analyzer

Chemical oxygen demand refers to the amount of oxygen required to completely oxidize all oxidizable substances in a sample. To determine COD, the sample needs to be heated and a digestion reagent added; after digestion, the sample color changes. The degree of color change is proportional to the concentration of carbon compounds, measured photometrically and the final value determined based on a preset absorption curve.

High-Temperature Combustion Method TOC Analyzer

The analyzer is based on thermal catalytic combustion and NDIR (non-dispersive infrared technology) detection of the CO2 product. Measurement is performed through two interrelated circuits:

1. In the liquid circuit, the water sample is acidified to remove inorganic carbon (stripping).
2. The water sample flows through a filter to separate particles.
3. The water sample flows into a furnace for combustion.
4. After the combustion gas is cooled, the CO2 concentration is determined by an NDIR detector.

SAC Analysis with Ultraviolet (UV) Sensors

Many organic substances absorb ultraviolet light at a wavelength of 254 nm, and the analyzer measures based on this principle. The UV beam emitted by a strobe light source is split and directed through different filters before being received by two receivers. One detector measures the light intensity at the measurement wavelength (254 nm), and the other detector measures the light intensity at the reference wavelength (550 nm). The measurement result is the ratio of the two measurement wavelengths and is converted into a SAC value based on a preset calibration curve.

Product Advantages

• Wide range of applications, from rapid online measurement to compliant online analysis.
• Provides COD standard solutions and reagents, as well as TOC standard solutions and reagents, for standardized high-precision measurement, and provides all required Material Safety Data Sheets (MSDS).
• The sample pretreatment system helps prepare homogeneous water samples for total organic carbon monitoring. The Y-type filter unit enables easy process integration and provides representative water samples with the correct solids content.
• Using the Liquiline System CA80 analyzer, up to four Memosens sensors can be connected, providing a more detailed process overview without the need for other measuring devices.
• Optical SAC sensors require no reagents and measure directly online, with multiple measuring ranges, covering applications from water to industrial wastewater.

Comparison of Key Parameters

Choosing the right analyzer requires comprehensive consideration of accuracy requirements, response speed, and operating costs. For situations requiring regulatory compliance, TOC or COD analyzers are recommended; for cost-effective continuous monitoring, SAC sensors are the ideal choice.