Organic carbon compounds are often specified in terms of carbon mass. Recent developments in TOC (total organic carbon) analysis have resulted in considerable improvements, which allow for complete and direct measurement of the quantity of carbon with a biological source. Where there are fluctuations and differences, the cause and effect on biological processes in waste water study can be identified.
The TIC (total inorganic carbon) is usually removed from a sample by means of purging prior to oxidizing the residual organic carbon in the water sample to carbon dioxide (CO2) and then quantifying the amount of CO2 generated (Figure 1).

Figure 1. Typical TOC process
A number of techniques are available which can be used to oxidize the organic carbon, such as oxygen, UV radiation, wet chemistry, or heat to generate CO2. Regardless of the method, the resulting CO2 is dissolved in a carrier gas, such as oxygen. This carrier gas is passed via the TOC level will also be higher and the water sample will be more contaminated.
Based on the cleanliness of the water being analyzed and the methods utilized, different concentrations of CO2 can be anticipated in the carrier gas, from wastewater to drinking water. Edinburgh Sensors’ Gascard® NG is a high performance OEM gas detector that provides real-time measurement of CO2 0-500ppm to 0- 3%.
OEM Gascard® NG
A suitable OEM solution for TOC monitoring, Gascard NG can be easily integrated into a range of gas detection solutions where lasting stability, high quality, superior repeatability and reliable measurement of carbon , CO2 and methane gas concentrations are needed. These features are due to Edinburgh Sensors’ proprietary dual wavelength fail to safe InfraRed (NDIR) sensor technology. The Gascard NG range offers ideal solutions for measuring and testing industrial as well as environmental gases. Table 1 shows the Gascard NG models for gas measurement range of CO2.
The Gascard NG from Edinburgh Sensors comes with different interface options, such as true RS232 communication, analogue 4-20 mA/0-20 mA/0-5 v, serial interface for interfacing relay alarms and optional on board LANsupport. The on-board firmware is capable of supporting a modern graphical display or a conventional 4 segment LCD.
In addition, the Gascard NG series needs only minimum maintenance and thus eliminates significant amount of costs. Automatic pressure and temperature correction features allow real-time environmental condition measurements and thus provide consistent measurement and exact concentration readings of target gases.
The sensor head and electronics of the Gascard NG series are positioned on a Eurocard PCB with several bit-switches, which allow users to control different aspects of the sensors behaviour such as filter type and analogue output selection.
The Gascard NG is backward compatible with outputs from current generations of Gascard series and includes onboard true RS232 communications with the option of TCP/iP communications protocol and on-board data logging. With built-in features for multi-sensor and multigas operation, the Gascard NG can integrate additional gas detection technologies.