Nitrogen Oxides

nox

What is Nitrogen Oxide?

The nitric oxide (NO) molecule is quite reactive and unstable. In ambient air, it reacts with oxygen to form the toxic nitrogen dioxide (NO2).

Where does Nitrogen Oxide come from?

Nitrogen oxide is mainly an unwanted by-product of fuel combustion at high temperatures.
Cars and power plants are the main sources of nitrogen oxide.

What are the effects of Nitrogen Oxide?

Nitrogen oxide causes a multitude of symptoms, primarily in the lungs but also in other organs such as the spleen and liver. Additionally, nitrogen oxide is jointly responsible for acidification and over-fertilisation of soil and water. Gaseous nitrogen oxide may become particulate ammonium nitrate. This contributes to large-scale PM (PM2.5, PM10) pollution. During the summer, nitrogen oxide and hydrocarbons cause formation of ground-level ozone and destruction of the ozone layer.

Measurement Principle:
Chemiluminescence (EN14211)

Nitric oxide in sample gas reacts with ozone to form nitrogen dioxide. This reaction results in electrically excited molecules. These molecules release their excess energy by emitting photons, which are measured by a photomultiplier tube. The airpointer NOX module is equipped with a delay loop to measure NO and NO2 from the same sample.

Zero Air Supply Check and Span Point Check

Zero air supply is part of the standard equipment so that a zero point check may be carried out automatically (e.g. daily).
An internal NO2 source for a regular span point check is available as an option.

Measured Compound Nitrogen Oxides NO/NO2/NOX
 EU Directive / USEPA Procedure  Chemiluminescence (EN14211)
Measurement principle Chemiluminescence
Range Dynamic, up to 20 ppm
Zero noise 0.2 ppb RMS
Lower detection limit 0.4 ppb
Zero drift (24 hours) < 0.4 ppb
Span drift (24 hours) +/- 1% of reading > 100 ppb
Response time < 60 seconds
Precision 1% of reading or 1 ppb (whichever is greater) @ < 500 ppb ±1% of reading >100 ppm
Linearity +/- 1% of reading >100ppm
Sample flow rate 1000 ml/min
Weight 12.0 kg/ 26.5 lbs

Ozone

What is Ozone?

Ozone (O3) is a highly toxic corrosive substance and a common pollutant. In low concentration it is a normal component of ambient air. Highly concentrated it is an aggressive irritant gas and at ground level it affects humans and nature.

Where does Ozone come from?

Ozone is formed in the atmosphere by reaction of nitrogen oxides, hydrocarbons, and sunlight. Ozone protects us in higher air layers (stratosphere) from harmful UV radiation. At ground level, higher ozone concentrations form only by other pollutants (ozone precursor chemicals) and sunlight. Nitrogen oxides and volatile organic compounds are the main precursors. Furthermore, methane and carbon monoxide (CO) contribute to the global formation of ozone. Insolation promotes the formation of ozone. High ozone concentrations thus occur mostly at midday and in the afternoon. Major sources of ozone are the chemical processes caused by industry and traffic as well as electrical current of television sets, computers, photocopiers, and electric motors (using brushes).

What are the Effects of Ozone?

Ozone causes above all respiratory ailments such as respiratory syndromes, changes in pulmonary function, increased respiratory sensitivity, and inflammation of the respiratory tract. Ozone additionally destroys the foliage of trees and other plants (photooxidation), thus aggravating the environment.

Measurement Principle:
UV absorption (EN 14625)

A beam from a high-energy UV lamp is directed through a tube filled with sample gas. Absorption effected by ozone is measured with a detector at the end of the tube.

Zero Air Supply Check and Span Point Check

Zero air supply is part of the standard equipment, so that a zero point check may be carried out automatically (e.g. daily).
An internal ozone generator for a regular span point check is available as an option.

Measured Compound Ozone O3
EU Directive / USEPA Procedure UV photometry (EN14625)
Measurement principle UV photometry
Range Dynamic, up to 20 ppm
Zero noise 0.25 ppb RMS
Lower detection limit 0.5 ppb
Zero drift (24 hours) < 1 ppb
Span drift (24 hours) ±1% of reading or 1 ppb (whichever is greater)
Response time < 30 seconds
Precision 1 ppb
Linearity +/- 1% of reading > 100 ppb
Sample flow rate approx. 1000 ml/min
Weight 5.8 kg/12.8 lbs,

Sulfur Dioxide

so2

What is Sulfur Dioxide??

Sulfur dioxide (SO2) is an acid-forming, colorless, foul-smelling and toxic gas.

Where does Sulfur Dioxide come from?

SO2 mainly comes from burning coal and heavy fuel oil.
Major sources are firing systems in energy business, in industry, and small-scale heating systems that use poor quality sulfurous oil or coal.

What are the Effects of Sulfur Dioxid?

Sulfur dioxide may cause humans to suffer from headaches, nausea, reductions in pulmonary volume, increases in breathing resistance, and symptoms such as wheezing, chest tightness, and shortness of breath. Sulfur dioxide is one of the major „acid rain“ precursors which compromises ecological systems such as forests and lakes as well as it accelerates corrosion of buildings and monuments. Sulfur dioxide may reduce visibility as part of smog.
Furthermore, particulate sulfate adds to large-scale PM (PM2.5, PM10) pollution.

Measurement Principle:
UV Fluorescence (EN14212)

Sample gas is lighted with an UV lamp, which causes the SO2 molecule to absorb energy. The absorbed energy is emitted as a light pulse (photon) which is measured with a photo multiplier.

Zero Air Supply Check and Span Point Check

Zero air supply is part of the standard equipment, so that a zero point check may be carried out automatically (e.g. daily).
Internal SO2 sources for a regular span point check are available as an option.

Measured Compound Sulfur Dioxide SO2 and Hydrogen Sulfide (H2S)
EU Directive / USEPA Procedure UV Fluorescence (EN14212) – for SO2
Measurement principle UV Fluorescence
Range dynamic, up to 10 ppm
Zero noise 0.25 ppb RMS
Lower detection limit 0.5 ppb
Zero drift (24 hours) < 1 ppb
Span drift (24 hours) ±1% of reading >100 ppb
Response time < 90 seconds
Precision 1% of reading or 1 ppb (whichever is greater)
Linearity ±1% of maximum >100 ppb
Sample flow rate 500 ml/min
Weight 8.5 kg/18.7 lbs,

Hydrogen Sulfide

What is Hydrogen Sulfide??

Hydrogen sulfide (H2S) is a highly toxic and corrosive, nauseously smelling gas.

Where does Hydrogen sulfide (H2S) come from?

H2S is a gas that results from biodeterioration and biodegradation. Major sources are refineries, furnaces, pulp and paper industry, gasworks, coking plants, sewage plants, and biogas plants

What are the Effects of Hydrogen Sulfide?

H2S destroys the body’s own hemoglobin and paralyses oxygen transport in blood. When it comes in contact with mucous membrane, it converts to form alkaline sulfides and causes eye, nose, throat and lung irritations. Its high acidity makes H2S a corrosive gas and may cause damage to electronic components.

Measurement Principle:
Thermal conversion to SO2

SO2 is scrubbed from the sample gas. H2S is thermally converted to SO2 and measured by UV fluorescence. Equipped with an H2S module the airpointer measures only H2S or only SO2 or both cycling with a minimum switching time of five minutes.

Zero Air Supply Check and Span Point Check

Zero air supply is part of the standard equipment, so a zero point check may be carried out automatically (e.g. daily).
Internal H2S sources for a regular span point check are available as an option

Carbon Monoxid

co

What is Carbon Monoxide??

Carbon monoxide (CO) is an extremely toxic gas resulting from incomplete combustion of carbon and carbonaceous products.

Where does Carbon Monoxide come from?

Carbon monoxide is mainly a product of incomplete combustion of fuel and propellants. Major sources are traffic, industry and smoking indoors.

What are the Effects of Carbon Monoxide?

CO as pollutant is especially significant because of its toxic effect to humans (damaging hemoglobin). Furthermore CO plays a significant role for photochemical generation of ground-level ozone on a global scale.
A certain concentration may reduce the amount of oxygen received by a person’s brain. The person may lose conscience or suffer permanent brain damage caused by lack of oxygen. Carbon monoxide may also contribute towards global warming.

Measurement Principle:
NDIR Gas Filter Correlation (EN14626)

An infrared source beam is directed through a chamber filled with sample gas.
Carbon monoxide absorbs this light. A photo-detector measures the emanating decrease.

CO Scrubber Check and Span Point Check

A „CO scrubber“ (catalytic converter) removes CO from the sample, so a zero point check may be performed automatically (e.g. daily).
An internal CO source for a regular span point check is available as an option.

Measured Compound Carbon Monoxide CO
EU Directive / USEPA Procedure NDIR gas filter correlation (EN14626)
Measurement principle NDIR gas filter correlation
Range Dynamic, up to 1000 ppm
Zero noise 0.02 ppm RMS
Lower detection limit 0.04 ppm
Zero drift (24 hours) < 0.1 ppm
Span drift (24 hours) ±1% of reading >10 ppm
Response time < 60 seconds
Precision ±0.1 ppm
Linearity ±1% of reading < 1,000 ppm
Sample flow rate approx. 500 ml/min
Weight 9.0 kg/19.8 lbs

Additional Sensors

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Additional airpointer Sensors

Apart from the already installed modules the airpointer offers capabilities for implementing additional sensors and external instruments using the high performance airpointer data recording. These sensors are integrated via Ethernet, RS-232 or analog interfaces. Additional sensors are mounted outside or inside the airpointer depending on the space available.

The airpointer continuously manages and controls measurement data via a web based user interface. The high-performance airpointer features can be used for each additionally implemented sensor. This includes data recording over a period of several years, data backup and faster data access via the recordum portal, data download for local analyses and more.

The meteorological sensor Lufft WS 600 records the parameters wind direction, wind velocity, temperature, air pressure, relative humidity and precipitation.

The meteorological sensor Lufft WS 600 records the parameters wind direction, wind velocity, temperature, air pressure, relative humidity and precipitatio

Road traffic and public places
Noise level
Pedestrian counts
PM sampling
PM monitoring
Navigation systems (GPS)
UV radiation
Indoor air quality
Carbon monoxide (CO2)
Oxygen (O2)
Relative humidity
Temperature
Light intensity
Industrial hygiene
Toxic gases
Volatile organic compounds (VOC)

„The more we measure, the more we know“

Particulate Matter

What is Particulate Matter??

PM10 and PM2.5 are not single components but the mass concentration of all ambient air particles with an aerodynamic diameter smaller than 10 µm (PM10) or 2.5 µm (PM2.5).

Where does Particulate Matter come from?

Thresholds of these pollutants are frequently exceeded, especially in areas with strong vehicle traffic air pollution. This leads to an increased public awareness of PM issues.
Particulate matter comes from diesel exhaust particles, tire wear, brake dust, and swirling road dust generated by vehicle traffic.

What are the Effects of Particulate Matter?

PM2.5 and PM10 have a short-term effect on the cardiovascular system. Evidence of a direct relation between the number of heart attacks and PM concentration has been substantiated. For instance, a long-term effect of PM pollution is the potential to carry and hold toxic compounds in the respiratory system. Particles in lungs and bronchia weaken the immune system.

Measurement Principle:
Nephelometry

The airpointer PM module uses nephelometry, the proven optical method of measurement. A sample heater minimizes the effects of humidity. The module uses a light-scattering photometer with a near-IR LED, a silicon detector hybrid preamplifier and a reference detector. The scattered light is proportional to PM concentration.

Size selection

A TSP inlet is part of the standard equipment of the PM module. Simply change the optionally available size-selective inlets to measure PM10 or PM2.5

Measured Compound Particulate Matter
EU Directive / USEPA Procedure Particle collecting and gravimetric analysis
Measurement principle Nephelometry
Range Dynamic, up to 2,500 µg/m³
Zero noise
Lower detection limit < 1 μg/m3
Zero drift (24 hours) < 1 μg/m3
Span drift (24 hours) ±1% of reading
Response time < 60 seconds
Precision 1 μg/m3
Linearity
Sample flow rate 2 l/min
Weight

The airpointer +PM comes with an approved PM analyzer integrated into the housing.

airpointer +PM

The airpointer +PM can be equipped with an approved PM analyzer. Furthermore, you may connect the airpointer to an external PM analyzer by using the available interfaces. Thus you may as well use the airpointer’s advantages especially within data recording and data transfer for measuring PM.

Measurement Principle:
Beta Ray Attenuation

Beta ray attenuation is a radiometric measurement. The particles are deposited on a filter belt and exposed to beta radiation. Varying beta absorption during sampling defines the mass of the deposited particles.

Measured Compound Particulate Matter
EU Directive / USEPA Procedure
Measurement principle
Radiation source
Range
Lower detection limit (24 hours)
Zero drift (24 hours)
Resolution
Sample flow rate
Particle collecting and gravimetric analysis
Beta ray attenuation
14C (Carbon14) 60 µCi ±15 µCi, half-life of 5730 years
Dynamic, up to 1.000 mg/m³
< 1 μg/m3
< 1 μg/m3
0.1 µg/ m3
16.7 l/min