Abstract: An ultrapure water trap is provided for retaining condensed water of water vapor which is formed in a TC oxidative reaction part, and a passage is so connected that an automatic sample injector can collect ultrapure water from the ultrapure water trap for injecting the same into the TC oxidative reaction part. The automatic sample injector dilutes ordinary pure water which is outside this apparatus with the ultrapure water which is retained in the ultrapure water trap, thereby preparing a test solution having ultralow carbon concentration of not more than 50 ppbC in the interior of a TOC meter.

Abstract: An inorganic carbon removing part defined by has a double tube structure formed by an inner tube of polytetrafluoroethylene having continuous pores and an outer tube of resin. An acidified sample solution is guided into the inner tube and an alkalified sample solution is guided into the outer tube, and inorganic carbon contained in the acidified sample solution is outwardly moved toward the alkalified sample solution to be removed. The acidified sample solution, from which inorganic carbon is removed, is injected into a combustion tube, so that a carbon component contained in the sample solution is converted into carbon dioxide and detected by a detecting part. Since the alkalified sample solution contains purgeable organic carbon components of the same concentration as the acidified sample solution, the content of total organic carbon is correctly measured with no loss of the purgeable organic carbon components.

Abstract: A non-dispersive infrared analyzer and method for analyzing a concentration in a gas utilizes an infrared light source and a cell configured to have a gas flow therethrough. The cell also has an infrared light passage through which a sample gas stream and an infrared light beam can travel. A sector has at least two filters for filtering infrared light, and is provided with the apparatus. The sector alternately inserts the at least two filters into the infrared beam. A detector detects wavelengths of the infrared light beam which corresponds to an absorption band of the gas to be measured, and a second wavelength which corresponds to an absorption band of the preselected reference gas. The detector receives the infrared light beam after the light beam has traveled through the sample cell.

Abstract: A purgeable organic carbons analyzer for measuring the content of purgeable organic carbons (POC) in a water sample using barium hydroxide as the CO.sub.2 absorbing agent in a CO.sub.2 absorber.

Abstract: A sampling needle and a ventilation pretreatment needle for sparging out a gas containing no carbon component are mounted on the same arm mechanism to be simultaneously driven. The sampling needle is adapted to introduce samples as well as to distributively inject acid into sample containers. The ventilation pretreatment needle is adapted to stir samples during sampling as well as to pretreat next samples during analysis.

Abstract: A carbon analyzer capable of measuring carbon contents of both liquid and solid samples under appropriate conditions includes not only basic components of a total organic carbon (TOC) analyzer such as a carrier gas supplying unit 22, a sample injection unit 2 for a liquid sample 6, a liquid sample combustion-oxidation vessel 12 and a CO.sub.2 detector 46, but also a solid sample intake unit 26 for receiving a solid sample, converting its carbon components into CO.sub.2 and sending it into the CO.sub.2 detector 46 together with a carrier gas. The CO.sub.2 detector 46 is a non-dispersive infrared analyzer with two measuring cells 48a and 48b having different lengths and disposed in series with a light flux such that the light flux will have different optical path lengths through these measuring cells 48a and 48b. A switching valve 44 serves to direct the gas to be tested selectively to either of the measuring cells 48a and 48 b and the carrier gas to the other as a purge gas.