Applications Overview

Guided Wave’s use of NIR and UV/Vis technologies and spectroscopic techniques provides an effective and efficient means of monitoring and controlling production in real-time. over the last 35 years, Guided Wave has developed experience with providing spectroscopic solutions to a variety of industries. Looking for an application not listed below? Fill out our application questionnaire and let us help you solve your process problem. The following is a list of applications proven with Guided Wave Analyzers.

Product Pipeline Interface Detection by NIR Spectroscopy

Petroleum product pipelines provide an efficient method of delivering product to distribution terminals. These multi-purpose pipelines deliver many different fuels often injected into the pipeline in a sequential fashion with no physical barriers between products. The receiving terminal must detect and separate the products in order to send them to the appropriate tanks and also identify off-specification product.



On-Line Monitoring of APHA Color (ASTM D1209)

APHA is sometimes referred to as the Platinum- Cobalt (Pt/Co) or Hazen scale. Also referred to as a “yellowness index”, the APHA color scale is a common method of comparison of the intensity of yellow-tinted samples to assess the quality of liquids that are clear to yellowish in color. Discover how real-time monitoring of APHA color (sometimes referred to as Hazen) either on-line or in a laboratory setting using a photometer can improve your process.



Monitoring the Percent Aromatics in Gasoline by NIR

The aromatic content of gasoline determines many of its combustion properties. Since it also impacts the environmental characteristics of the fuel it is desirable to have accurate measurements of this parameter. The traditional analytical method for measuring aromatics is either gas chromatography (GC) or an older method entitled fluorescent indicator adsorption (FIA), both of which are time and labor intensive. Learn how Guided Wave hardware and software can provide real-time measurement of % aromatics in fuel products using fiber optic-based, Near-Infrared (NIR) spectroscopy.



On-line Monitoring of ASTM Color (0-7) With a ClearView® db Photometer

ASTM color (reference ASTM D1500, ASTM D1524) describes the color measurement method for fuels including lubricating oils, heating oils, diesel fuels, and petroleum waxes.  The lowest value of 0.5 being a light yellow, 2 being yellow, 5 being orange, and 8 being a deep red. ASTM color is an important product quality measurement for many refinery and petrochemical processes.



Percentage of Benzene in Gasoline

The NIR spectra of a group of 150 different process gasoline samples with known benzene concentration ranging from 0.2 to 6.0% were measured between 1000 and 1600 nm using a Guided Wave NIR Spectrometer. NIR is a time and money saving alternative to traditional methods.



Cetane Number of Diesel Fuels

The Cetane number of a diesel fuel is a measure of the ignition properties and is an important specification that must be met during fuel production. The traditional laboratory method for Cetane number determination is the knock engine method in which the fuel is burned and its combustion characteristics compared to known standards. This method is time and labor intensive, and provides no ability for real-time control of production. This note discusses the use of Guided Wave hardware and software for the measurement of Cetane number in diesel fuel using fiber optic-based, Near-Infrared (NIR) spectroscopy.



On-Line Control of a Styrene Tower

A Clearview Dual Beam Photometer was installed at a Styrene production tower to monitor the concentration of styrene in ethylbenzene in the presence of toluene and benzene. The MLR calibration for styrene in 10 overhead samples resulted in an R2 of 0.999 with a standard error of 0.84% styrene.



Safe Operation of your EDC Reactor

Ethylene dichloride (EDC) plants need to monitor the ethylene content in the vent gas. By using Near Infrared Spectroscopy, the control systems can maintain a constant concentration in the vent gas and also ensures that the concentration is maintained at safe levels during start-up.



On-Line Monitoring of Caustic & Carbonate

Learn about the simultaneous measurement of caustic (NaOH) and sodium carbonate in aqueous process streams, particularly at low (<2%) caustic concentrations, using a ClearView db NIR photometer and fiber optic probe.




Monitoring Triazines and their Precursors

Learn about the measurement of various triazines using fiber optic-based, UV-Vis spectroscopy. Atrazine is a common contaminant in ground and surface water where it is slow to degrade. Agricultural runoff is the major source of surface water contamination. The US EPA Maximum Containment Level Goal (MCLG) for drinking water is 3ppb.



On-Line Monitoring of Turbidity or Haze

real time monitoring of a pipelineAlongside the measurement of Color, Turbidity is a property of interest for monitoring the quality of a fuel. Learn how Guided Wave has developed a Color and Turbidity monitor which is directly compliant with ASTM method D4176.



Continuous Fuel Identification for Pipelines

real time monitoring of a pipelineReliable, affordable, real-time identification of petroleum products flowing in pipelines can enable terminals to identify the ideal time (t90) and switch to the correct storage vessel. This help to minimize waste and the need for reprocessing petroleum products.



Realtime Octane Number Determination

real time monitoring of a pipelineThe Octane number rating of a gasoline is an indication of how the gasoline will perform under various engine conditions. Two different ratings are included: Research Octane Number (RON) and Motor Octane Number (MON). Finished gasoline must meet certain Octane number specifications. Thus refineries control this parameter during production and must certify that a gasoline meets specification before it is released. Learn how Guided Wave can help ensure proper Octance levels avoiding the delay of an engine knock test.



Color in LNG (liquefied natural gas)

real time monitoring of a pipelineMeasuring the Saybolt or ASTM color online is a key parameter in many light hydrocarbon mixes, such as Liquid Natural Gas for quality control. Monitoring the color allows the refiner to verify that the product is within specification and identify any “out of spec” product for reprocessing before being sold.



On-Line Monitoring of Saybolt Color

real time monitoring of a pipelineSaybolt color (reference ASTM D156, ASTMD6045) is primarily used in characterizing fuels including automobile and aviation gasolines, jet fuel, diesel fuel and other petroleum products. The Saybolt color scale goes from 30, which a barely perceivable yellow, to –16 which is a definite yellow. Learn how Guided Wave can provide cost-effective, explosion proof, field ready Saybolt  Color monitors. 



Iodine Value of Oils

real time monitoring of a pipelineAn important characteristic of a fatty oil product is its iodine value (IV). This is a measure of the unsaturated fatty acid content and indicates the ease of oxidation or the drying capacity of the product. Empirically, the IV is expressed in terms of the number of centigrams of iodine per gram of sample. Learn how NIR can be applied in real time to directly monitor your process.



On-Line Monitoring of Water in Ethylene Glycols

Concentrations ranging from 0-100% water in EG, each at 20, 25, 30, 35, 40 and 45°C were scanned on a NIR-O Full Spectrum Analyzer. A four-wavelength multiple linear regression was performed, which resulted in excellent linearity (R2>.9999)



On-Line Monitoring of Water in Dimethylformamide

The ability to monitor low levels of water in dimethylformamide (DMF) is a key consideration in the production of 1,3 butadiene. The quality of the final product (purity) can be compromised when water in excess of 400ppm is present in the DMF solvent stream. NIR spectroscopy provides the ideal method for in-situ water measurement.



Measurements in Polyurethanes In Situ

Many aspects of polyurethane production such as isocyanate concentration can be measured using Near-infrared (NIR) spectroscopy. In situ monitoring in the reactor systems allows for control of important properties during the reaction and to determine the endpoint of the reaction, thus adding to the value and cost savings.



Determining Polymer / Resin Reaction Endpoint In Situ

Determining reaction endpoint in polymer/resin reactors is critical to achieve desired product properties, such as molecular weight. Knowing exactly when the reaction is over saves residence time and batch conversion time, and lowers the overall manufacturing cost. Learn how Guided Wave can help save you time and money with in-situ reaction monitoring and spectroscopy based reaction endpoint monitoring.



Real-time Determination of Ethanol in Gasoline

Ethanol is now a common biofuel additive for gasoline. The additional oxygen in ethanol provides for a cleaner burning fuel. The data presented demonstrates the measurement of the ethanol content of fuel using near-infrared (NIR) spectroscopy.



Online Monitoring of Polymer Melts using UV Fiber-Optic Spectroscopy

Polymer performance is directly related to the level of stabilizer. As a result, measurement and control of the additive concentration that is melt compounded into the polymer is crucial. Making these measurements in the melt offers many advantages over current offline quality control methods such as gas chromatography (GC) and high-performance liquid chromatography (HPLC). This application note will discuss an online UV/VIS method for monitoring the levels of hindered phenols and phosphites in polypropylene.



Safe and Efficient Control of the Acrolein Process

Acrolein (or propenal) is the simplest unsaturated aldehyde. It is a colorless liquid and is mainly used as a biocide or as a building block to other chemical compounds. Measurement of both the water and acetaldehyde concentration in the final product is required. Acrolein is toxic and, without online analysis, hazardous manual sampling will be needed. Near-infrared spectroscopy can provide the rapid, real-time, in-situ analysis of the Acrolein cross-linking process.



Cloud Point of Diesel Fuel

The Cloud Point of a diesel fuel is the temperature below which wax forms giving the fuel a cloudy appearance. This parameter is an important property of the fuel since the presence of solidified waxes can clog filters and negatively impact engine performance. The traditional laboratory methods for the measurement of Cloud Point are optical in nature, but rely on cooling the fuel for the wax formation to occur. Guided Wave’s NIR instrumentation can measure composition changes in the fuel that will be directly related to the wax formation and hence the Cloud Point.



Hydroxyl and Acid Numbers in Resin Melts

Learn how to monitor your hydroxyl and acid numbers online in resin melt and determine what the process yield will be. Alternatively, monitor your reaction to determine the end of reaction across multiple products.



A Word (or Two) About Online NIR Water Measurements in Liquid Samples

Water is perhaps the most common measurement made in the near-infrared (NIR). This is due to its strong effect on product properties and chemical reactivity of the starting materials. Learn some useful facts to consider when monitoring aqueous solutions with near-infrared spectroscopy. 



Monitor Cleaning Solutions in Semiconductor Wafer Manufacturing Process

One major challenge in operating wet chemical cleaning processes is maintaining optimal bath conditions required for uniform cleaning, reduced cycle times and minimal product rework. As an added benefit, accurate analysis of bath conditions makes the most efficient use of costly ultra-pure chemicals, and reduce chemical waste.  Learn how a Clearview photometer can be used to Monitor Cleaning Solutions in Semiconductor Wafer Manufacturing Process.



Monitoring breakthrough of Low Level Organics in Water

Saccharin is used as a sweetener and preservative in pharmaceuticals, nutraceuticals, and food and as an agent in semiconductor plating baths. Molecules similar to saccharin, i.e. benzo substituted heterocyclic rings, are used in semiconductor cleaning solutions. These applications often require control of organic concentrations in water in the 100 ppm range and below. Using Saccharin as a model trace contaminant learn how NIR can be used to identify when levels warrant replacement of the filter or reaction bath.



Automated Determination of Phosphoric Acid Concentration

The use of phosphoric acid solutions is common in the semiconductor industry to both clean and etch metal surfaces. The concentration of the phosphoric acid is important to optimize these processes. Typically the laboratory method used for this determination involves one or more titrations. Learn how spectroscopy can be used for online in-situ monitoring of Phosphoric Acid Concentration.



Monitoring Water In Solvents

Water can be detected at much lower levels in non-OH containing solvents since there is less interaction between the base solvent and the water. However, in OH containing solvents such as Methanol, water can be detected down to several hundred parts per million. The measurement of the water levels in solvents with NIR spectroscopy is both fast and reliable utilizing the Guided Wave hardware and produces results that are available in real-time (seconds) thus making it a valuable tool for process measurement.



Automated Monitoring of Benzotriazole Contamination For the Semiconductor Industry

Benzotriazoles have many uses. They can be used in the semiconductor industry in wafer cleaning, an anti-freeze ingredient for de-icing airplanes, in photographic developing baths, as a corrosion inhibitor for copper and bronze, a UV stabilizer in some plastics, and as a precursor for many pharmaceutical compounds. Though benzotriazoles are readily water soluble they are not significantly biodegradable or readily removed by common water treatment methods.  Therefore UV spectroscopy is a useful method for online monitoring of wastewater for benzotriazoles contamination.



Automated Determination of Tetramethylammonium Hydroxide in Water

For semiconductor wafer processing, the level of tetramethylammonium hydroxide in water is very critical in the developer blend system. The solution of tetramethylammonium hydroxide must be kept at 2.38%.  The concentrations of tetramethylammonium hydroxide can be easily measured at 2.38% by near-infrared (NIR) spectroscopy with a Guided Wave fiber optic coupled NIR-OTM Process Analyzer to better than ±0.1 % v/v. Analysis time is under 50 seconds.



Hydroxyl Number in Polyols

The use of polymeric polyols is commonplace in the manufacturing of polyurethanes and other specialty polymers. The hydroxyl number (OH#) is a measure of the concentration of the hydroxyl groups on the polyol. This is an important parameter to monitor and control during polyol production. Learn how NIR can be used for real-time monitoring of Hydroxy Number of polyol cross-linking reactions.



Fast Online Analysis of HPLC Binary Solvent Feed Mixtures

Binary solvent mixtures are used as carriers in production scale pharmaceutical HPLC separations. Analysis of the mixture ratios is required prior to injection into the HPLC column. The correct mixture ratio ensures efficient and correct separation of the chemical targeted for separation. Learn how this can be achieved with NIR



On-Line Monitoring of Ethylene Oxide Sterilization

Near Infrared Spectroscopy provides real-time measurement of ethylene oxide (EO) gas during sterilization cycles. Ideal for in sterilizer applications, this technology cannot be used for occupational health safety monitoring.


On-Line Monitoring of Epoxy Value

Real-time monitoring of the Epoxy Value enables you to see into the reaction and monitor the epoxide group content and ensure that proper cross-linking is occurring.


Online Montioring of Hydrocarbon Gas Streams

A common concern of hydrocarbon vapors, especially in ambient air mixtures, is the concentration relative to the Lower Explosion Limit (LEL). Guided Wave’s NIR instrumentation can make both qualitative and quantitative measurements in gas streams using long path gas cells coupled to our analyzer systems to monitor short-chain alkanes such as Butane.


Monitoring Reverse Phase LC of Acetonitrile/Water in Pharma Applications

A Clearview Photometer was used to monitor the Acetonitrile (ACN):water mobile phase gradients for the chromatographic separation of active Pharmaceutical ingredients.


Real-time Water Analysis in an Alcohol-Brine Solution

This application note indicates that a ClearView db fiber optic filter photometer with an analyzing wavelength of 1820 nm and a reference wavelength near 1050 nm can analyze water in the presence of alcohols and salt.


Monitoring Water in Acetic Acid & p-Xylene

Water can be analyzed near 1380 nm, independent of p-xylene or acetic acid content. Multiple linear regression (MLR) system- atically investigates which wavelength or wavelengths provide a statistically acceptable calibration. The MLR results confirmed that water can be determined solely at 1390 nm, and that acetic acid and p-xylene can be determined using two wavelengths at 1140 and 1380 nm.


Monitoring Water in Aromatic/Acetone Mixtures

Samples containing isopropyl benzene, acetone and phenol in approximately constant ratios were measured with a NIR Spectrophotometer. It was found that water in complex mixtures can be measured with an accuracy better than ±0.01% (wt.). Moreover, the spectrophotometer can utilize up to 2 fiber optic insertion probes flanged directly into a reactor or column, or flow cells on a slip stream for improved cost per sample point.


Monitoring Trazines and their Precursors In Agricultural Runoff

Agricultural runoff is the major source of surface water contamination. The US EPA Maximum Containment Level Goal (MCLG) for drinking water is 3ppb. The UV-Vis region of the electromagnetic spectrum displays electronic transitions and is particularly useful for viewing conjugated and aromatic molecules. By measuring the UV spectra of a series of samples of known atrazine or atrazine derivative concentration, a quantitative model can be developed which will allow the measurement of future samples based only on their UV spectrum.


Online monitoring of Hydrogen Peroxide Sterilization

Guided Wave's HPV analyzer is a simple turnkey solution for the measurement of hydrogen peroxide and water (H2O2 and H2O) concentrations in vapor phase. These are both measured together because they are codependent. The analyzer operates in real time, which takes the guesswork out of determining the H2O2 and H2O concentrations during cycle development and throughout the actual sterilization cycle.


Other Potential Applications

The following is a list of other potential applications:

  • UV Inhibitor Content
  • Saponification Number of oils
  • Residual Solvent and Trace Solvent Detection
  • Polymer Viscosity and Density
  • Phosgene in Solvent Wash (polyurethane synthesis)
  • NIR Spectroscopy of Various Chemical Processes
  • Trace copper Contamination in Sulfuric acid
  • Biodiseal Purity and Other Fuel Properties
  • HF (Hydrofluoric Acid) Concentration
  • Real-time Validation of Fuel Specifications during Blending Operations
  • Flash Point of Diesel and Other Petroleum Products