Teledyne API Model 200AU NOX Analyzer Instruction Manual, 02293, Rev. F

4 THE M200AU NOX ANALYZER

4.1 Principle of Operation

The Teledyne API Model 200AU Analyzer is designed to measure the concentration of nitric oxide [NO], total oxides of nitrogen [NOx] and, by calculation, nitrogen dioxide [NO2].

The instrument measures the light intensity of the chemiluminescent gas phase reaction of nitric oxide [NO] and ozone [O3] as follows:

NO + O3 → NO2 * +O2

NO2 * → NO2 + hv

The reaction of NO with ozone results in electronically excited NO2 molecules as shown in the first equation above. The excited NO2 molecules release their excess energy by emitting a photon and dropping to a lower energy level as shown in the second equation. It has been shown that the light intensity produced is directly proportional to the [NO] concentration present.

The Analyzer samples the gas stream and measures the [NO] concentration by digitizing the signal from the Analyzer's photomultiplier tube (PMT). A valve then routes the sample stream through a converter containing heated molybdenum to reduce any NOx present to NO by the following reaction:

315o C

3NOx + Mo → 3NO + MoO3

The Analyzer now measures the total NOx concentration. The [NOx] and [NO] values are subtracted from each other by the built-in computer, yielding the [NO2] concentration. In the third measurement phase, the instrument measures sample gas which has been mixed with ozone outside of the reaction cell. This Pre-Reactor allows the measurement of any hydrocarbon interferents present in the sample gas stream. The three results [NO], [NOx], and [NO2] are then further processed and stored by the computer yielding several instantaneous and long term averages of all three components.

The software uses an adaptive filter to accommodate rapid changes in concentration. The algorithm monitors the rate of change in concentration for both the NO and NOx channels. When a change in concentration is detected, the software changes the sample filters to rapidly respond to the change. The filters are adjusted to minimize the errors introduced by the time delay between the NOx and NO channel measurements; this assures accurate NO2 measurements. When the rate of change decreases, the filters are lengthened to provide better signal/noise ratio. The parameters used to operate the adaptive filter have been tuned to match the electrical and pneumatic characteristics of the M200AU.

4-1

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Teledyne instruction manual M200AU NOX Analyzer, Principle of Operation
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200AU specifications

The Teledyne 200AU is a cutting-edge analytical instrument designed primarily for trace and ultra-trace analysis of elements in various liquid samples. Renowned for its reliability and precision, this inductively coupled plasma mass spectrometer (ICP-MS) is widely utilized in environmental monitoring, food safety, clinical diagnostics, and geochemical research.

One of the distinguishing features of the Teledyne 200AU is its exceptional sensitivity, allowing for the detection of elements at concentrations as low as parts per trillion (ppt). This sensitivity is crucial for applications where even minute traces of contaminants can have significant implications. The instrument also boasts a wide dynamic range, accommodating high-concentration samples without compromising accuracy.

The Teledyne 200AU incorporates advanced technologies that enhance its analytical capabilities. At the core of its design is a robust ICP source, which ensures optimal ionization efficiency. The instrument also features a high-resolution quadrupole mass analyzer, which enables precise separation and identification of ions based on their mass-to-charge ratio. This feature is essential for distinguishing between isotopes and analyzing complex mixtures.

Another notable characteristic of the Teledyne 200AU is its user-friendly interface, which simplifies the operation and data management processes. The software is intuitive, offering sophisticated data processing algorithms that streamline analysis. Users can easily access real-time data visualization, facilitating timely decision-making based on analytical results.

The instrument is built with durability in mind, featuring a compact design that allows for easy integration into various laboratory environments. The Teledyne 200AU is also equipped with state-of-the-art safety features, including enhanced cooling systems and automated shutdown protocols to protect both the instrument and the user.

Moreover, the Teledyne 200AU supports a variety of sample introduction methods, including nebulization and laser ablation, providing flexibility to accommodate different types of samples and experimental needs. Its multi-element capability further enhances its versatility, allowing simultaneous detection of multiple elements in a single analysis.

In summary, the Teledyne 200AU stands out as a premier instrument in the field of mass spectrometry. Its combination of high sensitivity, advanced technology, user-friendly features, and robust design makes it an invaluable tool for scientists and researchers seeking precise elemental analysis across various disciplines.
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