Glossary Terms  The most common term used in gas measurement

The most common term used in gas measurement

 

Systech Illinois offer adapters with our permeation analyzers to enable testing and measurement of different shaped films, bottles and packages.

 

Also called an eductor-jet pump or filter pump, it is a device that produces vacuum by means of the Venturi effect. Fluid (liquid or gaseous) flows through a tube which then narrows. When the tube narrows, the fluid"s speed increases, and because of the Venturi effect, its pressure decreases. Vacuum is taken from this point.

 

The aluminium oxide sensor is, by function, a capacitor The sensor is capable of measuring ppm and dew point measurements in most industrial gas streams.

 

The Ambient Oxygen Ingress Rate (AOIR) method, can measure the permeability of oxygen through films in finished packaging. The PermMate Oxygen Permeation Analyzer uses this method.

 

The ATEX directive consists of two EU directives describing what equipment and work is allowed in an environment with an explosive atmosphere.

 

A unit of gauge pressure, i.e. pressure in bars above ambient or atmospheric pressure.

 

British Approvals Service for Electrical Equipment in Flammable Atmospheres. Certification body for equipment intended for use in hazardous areas.

 

A ball grid array (BGA) is a type of surface-mount packaging used for integrated circuits.

 

Calibration gas is used in testing for gas analyzers, oxygen analyzers and permeation gas analyzers.

 

The European Committee for Electrotechnical Standardization. A body developing electrotechnical standards for the Single European Market / European Economic Area in order to reduce internal frontiers and trade barriers for electrotechnical products, systems and services.

 

A product packaged in a low-oxygen, nitrogen-rich wrap that preserves freshness.

 

This non-depleting sensor does not require periodic replacement.  Systech Illinois use this first principle measurement in their Permeation analyzers and Moisture analyzers. The principle of Coulometry though is the same. Coulometry is the name given to a group of techniques in analytical chemistry that determine the amount of matter transformed during an electrolysis reaction by measuring the amount of electricity (in coulombs) consumed or produced.

 

The Canadian Standards Association is a global safety company that sets standards for scientific instrument design and operates a certification process for those standards that verify the design. Many companies in Canada will require that the products they purchase are certified to CSA.

 

Refer to CSA and UL in this glossary. CUL is a certification process that in some products may provide adequate standards for both UL and CSA.

 

The magnetodynamic or `dumbbell" type of design is a non-deleting method of measuring percent levels of Oxygen. Oxygen has a relatively high magnetic susceptibility as compared to other gases such as nitrogen, helium, argon, etc. and displays a paramagnetic behaviour. The paramagnetic oxygen sensor consists of a cylindrical shaped container inside of which is placed a small glass dumbbell. The dumbbell is filled with an inert gas such as nitrogen and suspended on a taut platinum wire within a non-uniform magnetic field. 

 

The dumbbell is designed to move freely as it is suspended from the wire. When a sample gas containing oxygen is processed through the sensor, the oxygen molecules are attracted to the stronger of the two magnetic fields. This causes a displacement of the dumbbell which results in the dumbbell rotating. A precision optical system consisting of a light source, photodiode, and amplifier circuit is used to measure the degree of rotation of the dumbbell. In some paramagnetic oxygen sensor designs, an opposing current is applied to restore the dumbbell to its normal position. The current required to maintain the dumbbell in its normal state is directly proportional to the partial pressure of oxygen and is represented electronically in percent oxygen. There are design variations associated with the various manufacturers of magnetodynamic paramagnetic oxygen analyzer types. Also, other types of sensors have been developed that use the susceptibility of oxygen to a magnetic field which include the thermomagnetic or `magnetic wind" type and the magneto pneumatic sensor. In general, paramagnetic oxygen sensors offer very good response time characteristics and use no consumable parts, making sensor life, under normal conditions, quite good. It also offers excellent precision over a range of 1% to 100% oxygen. The magnetodynamic sensor is quite delicate and is sensitive to vibration and/or position. Due to the loss in measurement sensitivity, in general, the paramagnetic oxygen sensor is not recommended for trace oxygen measurements.

 

Intrinsically Safe apparatus which can be installed in hazardous areas, certified to EN standard. For example ATEX approved, Intrinsically safe analyzers.

 

Also known as Electrochemical Fuel Cell. All electrochemical oxygen sensors are of the self powered, diffusion limited, metal-air battery type, comprising an anode, a semi-solid electrolyte paste and an air cathode. Capable of measuring percent or trace (ppm) levels of oxygen in a gas or gas mixture. As used in our EC900 process oxygen analyzers.

 

Electron Beams are frequently used to initiate polymerization reactions and crosslinking of plastic materials. This process works by reacting liquid, uncured monomer substrates with highly accelerated electrons. This reaction instantaneously polymerizes the liquid monomer to a non-tacky, cured solid state. Applications include: coatings, inks, varnishes, films etc.

 

Faraday’s First Law, the quantity of a substance produced by electrolysis is proprotional to the quantity of electricty used. Faraday’s Second Law, for a given quantity of electricity the quantity of substance produced is proportional to its weight.

 

Owing to their high reactivity, the halogens are found in the environment only in compounds or as ions. Halide ions and oxoanions such as iodate (IO3−) can be found in many minerals and in seawater. Halogenated organic compounds can also be found as natural products in living organisms. In their elemental forms, the halogens exist as diatomic molecules, but these only have a fleeting existence in nature and are much more common in the laboratory and in industry. At room temperature and pressure, fluorine and chlorine are gases, bromine is a liquid and iodine and astatine are solids.

 

A systematic preventive approach to food safety and pharmaceutical safety that addresses physical, chemical, and biological hazards as a means of prevention rather than finished product inspection. HACCP is used in the food industry to identify potential food safety hazards, so that key actions can be taken to reduce or eliminate the risk of the hazards being realized. The system is used at all stages of food production and preparation processes including packaging, distribution, etc. Meat HACCP systems are regulated by the USDA, while seafood and juice are regulated by the FDA. The use of HACCP is currently voluntary in other food industries.

 

The process of sampling a gas contained within a package. The headspace is the area of free space not occupied by the product within a food or pharmaceutical package. The headspace gas can be analyzed using headspace gas analyzers.

 

An instrument used for measuring the moisture content in the environmental air, or humidity. Humidity is difficult to measure accurately. Most measurement devices usually rely on measurements of some other quantity such as temperature, pressure, mass or a mechanical or electrical change in a substance as moisture is absorbed. From calculations based on physical principles, or especially by calibration with a reference standard, these measured quantities can lead to a measurement of humidity. Modern electronic devices use temperature of condensation, changes in electrical resistance, and changes in electrical capacitance to measure humidity changes.

 

A non-reactive gas used during chemical synthesis, chemical analysis, or preservation of reactive materials. Inert gases are selected for specific settings for which they are functionally inert since the cost of the gas and the cost of purifying the gas are usually a consideration. Neon and argon are the most common inert gases for use in chemistry and archival settings.

 

Because of the non-reactive properties of inert gases they are often useful to prevent undesirable chemical reactions from taking place. For example molecular nitrogen, a molecular inert gas, is often used in food packaging to ensure that food does not spoil in transit since no bacteria or fungi can flourish without the reactive gases oxygen or carbon dioxide, which the molecular nitrogen displaces, since most extant cells on Earth require the reactions which these gases are involved in to function.

 

Infra-red analyzers may be used for measurement of carbon dioxide at any level between 0-100% in gases or gas mixtures. Systech Illinois" headspace analyzer range include infra-red analyzers.

 

A protection technique for safe operation of electronic equipment in explosive atmospheres and under irregular operating conditions. The concept was developed for safe operation of process control instrumentation in hazardous areas, particularly North Sea gas platforms. As a discipline, it is an application of inherent safety in instrumentation. The theory behind intrinsic safety is to ensure that the available electrical and thermal energy in the system is always low enough that ignition of the hazardous atmosphere cannot occur. This is achieved by ensuring that only low voltages and currents enter the hazardous area, and that all electric supply and signal wires are protected by zener safety barriers. Sometimes an alternative type of barrier known as a galvanic isolation barrier may be used. Systech Illinois offer a range of intrinsically safe analyzers suitable for hazardous areas.

 

The International Organization for Standardization (ISO) is an international standard-setting body composed of representatives from various national standards organizations. Founded on February 23, 1947, the organization promulgates worldwide proprietary industrial and commercial standards. While ISO defines itself as a non-governmental organization, its ability to set standards that often become law, either through treaties or national standards, makes it more powerful than most non-governmental organizations. In practice, ISO acts as a consortium with strong links to governments.

 

The Lyssy L100-5000 gas permeability analyzer uses the manometric principle, one of the oldest and most recognised gas permeability measuring methods which involves pressure change via gas transmission through films.

 

This is a technique used for prolonging the shelf-life of foods. In this preservation technique the air surrounding the food in the package is changed to another composition. This way the initial fresh state of the product may be prolonged. It is the shelf-life of perishable products like meat, fish, fruits and vegetables that will be prolonged with MAP since it slows the natural deterioration of the product. MAP is used with various types of products, where the mixture of gases In the package depends on the type of product, packaging materials and storage temperature. Meat and fish need very low gas permeability films so for non-respiring products (meat, fish, cheese etc.) high barrier films are used. The initial flushed gas-mixture will be maintained inside the MA package. But fruits and vegetables are respiring products where the interaction of the packaging material with the product is important. If the permeability (for O2 and CO2) of the packaging film is adapted to the products respiration, an equilibrium modified atmosphere will establish In the package and the shelf-life of the product will increase.

 

The UK"s National Measurement Accreditation Service, it"s accreditation standards are consistent with European and international accreditation standards. NAMAS assesses, accredits and monitors calibration and testing laboratories. Subject to its comprehensive criteria, these laboratories are then authorized to issue formal certificates and reports for specific types of measurements and tests. NAMAS accreditation is applicable to most disciplines of testing and calibration performed in independent commercial laboratories, manufacturing organizations, educational establishments and government departments.

 

A standard of the National Electrical Manufacturers Association defines a product, process, or procedure with reference to one or more of the following: nomenclature, composition, construction, dimensions, tolerances, safety, operating characteristics, performance, ratings, testing and the service for which it is designed.

 

The National Institute of Standards and Technology is a non-regulatory federal agency with the U.S Department of Commerce who provide technology and measurement standards for products and services.

 

Brand name for Systech Illinois" nitrogen control system and oxygen measurement technology. This control system is used in applications such as soldering ovens, UV curing systems and food packaging machines improving process control, product quality and saves on nitrogen usage and rework costs.

 

The oxygen measurement technique is based upon the fluorescence quenching of a metal organic fluorescent dye immobilized in a gas permeable hydrophobic polymer. The dye absorbs light in the blue region and fluoresces within the red region of the spectrum. The presence of oxygen quenches the fluorescent light from the dye as well as its lifetime. The quenching process is a purely collisional dynamic where the energy from the excited fluorescent dye is transferred to the oxygen molecule during a collision, hence, reducing the emission intensity as well as the fluorescent lifetime of the dye. Thus, the oxygen content of the enclosed space is not changed by the measurement process.

 

The electrolytic moisture sensor used by Systech Illinois employs the well known phosphorus pentoxide principle for accurate determination of trace levels of moisture in inert gas streams. Phosphorus pentoxide is a potent dehydrating agent. P205 (diphosphorous pentoxyde). P205 is a highly hygroscopic substance which absorbs the water from the sample gas. Through continuous dissociation of the water a balance between the water content of the sample gas and the water which is being dissociated builds up. The electrolysis current is proportional to the water content in the sample gas. It is displayed on the instrument readout after it is processed by the instruments signal amplifier.

 

Oxygen is a paramagnetic gas and is attracted to a strong magnetic field. Because this measurement is a purely physical effect, nothing is consumed and unlimited life. Contamination of the cell by dust, dirt, corrosives or solvents can lead to deterioration. A paramagnetic sensor is capable of measuring from 0.05% to 100% O2.

 

A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate.

 

The Systech Illinois percent sensor is capable of accurate measurements from 0-100% oxygen. Unlike other electrochemical sensors, this sensor is not affected by acid gases such as carbon dioxide.

 

Patented by Systech Illinois this sensor has a unique electrochemical cell which responds in seconds even to large changes in oxygen levels and is unaffected by solvent vapors or hydrocarbons making it ideal for use in systems where high oxygen levels are common.

 

Ensure that gas sensors receive stable, clean, sample gas streams.

 

Method for constructing electronic circuits in which the components (SMC, or Surface Mounted Components) are mounted directly onto the surface of printed circuit boards (PCBs). An electronic device so made is called a surface mount device or SMD. In the industry it has largely replaced the through-hole technology construction method of fitting components with wire leads into holes in the circuit board.

 

Each gas has a known thermal conductivity, how well heat transfers through it. Thermal conductivity is measured with a sensor that employs four matched filaments that change resistance according to the thermal conductivity of the gas passing over it.

 

The Systech Illinois trace (part per million) sensor is designed for measuring 0.1ppm - 1% oxygen in most industrial gas streams. It can be calibrated to air and when used in a normal operating range typically lasts 3-5 years.

 

The Systech Illinois turbopurge technology enables the purge time of greater volumes to be achieved in a shorter space of time. Because of the speed rate it is ideal for testing bottles and packages.

 

UL stands for Underwriters Laboratories, an independent US test organisation. UL Approval is often a requirement for equipment in use in the USA and other countries. It is a similar organisation to CSA, see above.

 

An electrical circuit used to measure an unknown electrical resistance by balancing two legs of a bridge circuit, one leg of which includes the unknown component. Its operation is similar to the original potentiometer.

 

The zirconia cell is a high temperature ceramic sensor. It comprises of two electronically conducting, chemically inert electrodes attached to either side of a solid electrolyte tube. Capable of measuring ppm to % levels of oxygen in a gas or mixture of gases. Used in our ZR800 oxygen analyzers.