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IAQ is the abbreviation of Indoor Air Quality. This refers to all aspects of airborne substances as well as their toxicological, physical, and physiological character. For 30 years now we at GRIMM Aerosol Technik specialize in detection of the smallest particles. Our instruments let us evaluate what is in the air and even more important where it is coming from. Our systems are exceptionally versatile and adaptable to your special need. Explore the possibilities - you will be surprised.

Indoor Air Quality measures the quantity and quality of particles in the air of indoor and public environments, e.g. classrooms, libraries, or pubs, and even busses and cars. This data is relevant to the health of human beings and the quality of their everyday's lives. For the quantity of aerosols there are three values important: The number, the size, and the mass of particles in the air. For the quality there even more aspects are relevant: Volatile, semi-volatile, liquid, and solid particles, as well as their toxicological aspects. How far do they penetrate our respiratory system. Besides the back then important dust mass values, more and more ultrafine particles are of interest.

Grimm Aerosol Technik has 30 years of experience in measuring particles relevant to IAQ. With the combination of the Grimm NanoCheck and the aerosol spectrometer, Grimm offers the only portable system for the entire indoor aerosol monitoring. For this reason our experience and expertise is relevant for you. We combine several ways of measuring the air quality with an unrivalled precision.

The sample air is led directly into the measuring cell via the aerosol inlet or other custom-designed air inlets, e.g. for high wind speeds or overpressure. The particles within the sample air are being detected by light scattering inside the measuring cell. The scattering light pulse emitted by every single particle is being counted, and the intensity of its scattering light signal is then classified as a certain particle size.

Optical systems are used for many years, but most of them are only NEPHELOMETERS. These systems are cheap but are not able to measure the aerosol distribution to precisely calculate the appropriate mass . Only multi-channel spectrometers have the ability to calculate the dust mass concentration (since the size acts in the 3rd power to the volume). GRIMM developed a 15 channel as well as a research instrument with 31 size channels to provide most accurate results in real time.

YES. All reference devices world-wide are gravimetric filter systems. Therefore GRIMM implemented a filter holder inside the monitor, so the collected sample can be weighed out and a correlation between the optically measured mass and the weighed sample can be established. This is necessary since different densities at different work place locations need an atmospheric aerosol correction factor (C-Factor). By entering this value all previously obtained values are now post-corrected. The basic idea behind this is to obtain a correlation accuracy r2 of these PM-values with gravimetrically measured PM-values. Due to this unique patented method of monitoring the inhalable, thoracic, and respirable mass fraction with one single instrument, thousands of such units are used world-wide every day.

YES. This method was first tested in Europe and follows therefore closely the European Regulation EN 481. This fully portable measuring device features next to the integrated filter for gravimetric post-evaluation the highlight of providing real-time data shown as a) Size and count distribution in over 15 or 31 different classes or
b) Mass distribution in over 15 or 31 different classes or
c) Simultaneously three IAQ values in one unit.

YES. All GRIMM IAQ monitors operate up to 8h powered by a RECHARGEABLE BATTERY inside. However they can also be operated via AC from 100 VAC to 230 VAC The most lightweight device weighs only 2.4 kg. All measured data can be shown on the display as well as transferred to the removable data logger.

YES. All GRIMM IAQ monitors measure particles smaller 1µm in several size channels down to 250 nm. Should there be any need for monitoring ultrafine particles, optional sensors permit monitoring this size range accumulative down to 25 nm, or differential in eight size channels ranging from 12 nm to 200 nm.

YES. All GRIMM IAQ monitors feature a port for three optional sensors such as wind speed, rel. humidity, and temperature. These data will also be transmitted.

All units have a data logger port to which the powerful DATA LOGGER by GRIMM enables the data collection from our dust monitor, meteorological data, as well as gas sensor data simultaneously. These results are stored in this logger and can also be transferred via LAN or WLAN to the central data acquisition system.

All GRIMM spectrometers have a RS-232 interface which transfers your data to any PC in real time or online via the data logger. Due to the powerful and user-friendly LABVIEW software ALL DATA obtained from all connected devices can be displayed simultaneously in real time.

YES. All GRIMM spectrometers have a built-in SERVICE mode where all components, such as laser, pump, etc. are constantly controlled and its functionality reported via the data logger. Therefore the instrument performance can be supervised at any time. This ensures the reliability and considerably reduces the maintenance efforts.

Very little! Both the 15 and the 31 channel spectrometer is an optical instrument and therefore does not need any extra service so that we only recommend an annual inspection of the instrument. This is not only a significant cost saving aspect, but also a great reduction in labor costs. Considering all costs during the extremely long life cycle of our instruments, you will get the best value for your money when deciding for our technology.

A nanometer is very small - 1 meter compared to 1 nanometer is like the Earth's diameter compared to the diameter of a Hazelnut. Our devices detect particles in a hitherto unknown precision and ease. Our primary aim is to satisfy YOU as our customer, and to make it work for YOU!


Measuring and assessing particulate matter within the ambient air is of prime importance: Limit values set by the World Health Organization (WHO) for human health protection are exceeded worldwide every single day. In highly congested urban areas in particular, the degree of contamination is clearly above those limit values with a serious impact on all those people subjected to it. In contrast to gaseous airborne pollutants, no minimum threshold can be scientifically defined for fine dust beneath the certain size where such dust particles do not have any further relevance to health. Due to 30 years of experience and expertise of our engineers and scientists - from the service department to the product development department to R&D - we are able to provide highest quality in all aspects of our product range and services

The sample air is led directly into the measuring cell via the aerosol inlet or other custom-designed air inlets, e.g. for high wind speeds or overpressure. The particles within the sample air are being detected by light scattering inside the measuring cell. The scattering light pulse emitted by every single particle is being counted, and the intensity of its scattering light signal is then classified as a certain particle size.

If you want to measure precise aerosol quantities and want to know the source of these fractions (maybe even a real-time correlation of the measurements is of interest) your standard nephelometer will not help a lot. The Nephelometer provides only the accumulative signal of all particles in its optical cell. Like this it is obvious that the calculation of the mass in the ambient air is not possible.

YES. Due to the unique patented method, monitoring PM-10, PM-2.5, PM-1, and even total counts is possible simultaneously with one single unit. All results are obtained within an measuring interval of 6 seconds upwards and can be averaged up to 15 min. intervals. As reference devices, gravimetric filter systems are used worldwide to measure PM-2.5 and PM-10. All information, such as different densities at different sizes and their refractive index that matches the composition of the atmospheric aerosol is preset by an approved algorithm. In general, the basic idea behind this algorithm is to correlate accuracy R2 of these PM-values with gravimetrically measured PM-values better than 0.95. GRIMM devices compute results from over 30 different size channels using our special algorithm. Since 1998 the development of this algorithm took several thousand hours of field tests in Europe, America, and Asia. Only after this period of testing and improving, GRIMM applied successfully for an instrument approval.

YES, this method was tested in Europe and first approved with the model EDM180 for PM-10 in Europe (EN 12341) five years ago and is successfully in use since. In addition, the same model EDM180 was tested and APPROVED in 2010 for PM-2.5 (EN 14907) and meanwhile the data (without any hardware modifications) the EDM180 delivers approved PM-10 and PM-2.5 values to networks. Field tests in the USA have also shown excellent accuracy in accordance to the reference systems and thus we successfully received the approval of the EPA.

YES. All GRIMM spectrometers have a built-in 31 channel sizer from 0.25 to 30 µm as well as the counting ability which the base for mass conversion. Therefore we offer optional operating modes:
(a) Measuring only the particle concentration and size distribution in intervals of 6 seconds upwards
(b) Units where you can change from counts to the PM values.

Most competitor systems have problems with the humidity correction at 60-99% non-condensing humidity. They only use heated sample pipes (or partially heated, so-called smart or intelligent heaters) to solve the problem of the additional mass of water to the filter weight. The GRIMM EDM series uses an isotherm method for nearly all applications, so we do not lose important semi-volatile compounds (SVC) in the air. This is done by extracting the water with Nafion filters if the humidity level exceeds 60% r.H. Therefore we are able to measure all airborne particles and not only the "solid particles". Depending on the location this can make a difference between 30 to 100% of the measurable mass.

YES. It is standard, that all GRIMM Environmental monitors submit the outdoor air temperature and humidity values each minute with the PM values. As an option you can also measure and submit the wind speed and direction, as well as the precipitation.

YES. Most competitor systems are heating the sample pipe above 60-99% non-condensing humidity and thus lose the SVC fraction. We offer an optional sample pipe with alternating heated and non-heated phases, which in consequence reveals the SVC contribution at any site in real-time. We use this heated sampling probe to determine the SVC fraction in real-time.

GRIMM Environmental monitors can be upgraded with a Nano sensor that measures Nanoparticles down to 10 nanometer. The most sophisticated method to measure fine and ultrafine particles is the Grimm Wide Range Aerosol Spectrometer (WRAS), a one-of-a-kind combination of an SMPS and an OPC. Please inquire for further information.

GRIMM has developed a powerful DATA LOGGER, enabling the data collection from our dust monitor, the meteorological data, as well as from different gas sensors simultaneously. These results are stored onto the logger but can also be transferred via LAN or GSM to the Grimm networks website in real-time.

YES. All data can be transferred to any external PC system. The powerful, yet user-friendly GRIMM SPECTROMETER SOFTWARE allows to see and analyze all data obtained from all attached units simultaneously and in real-time.

YES. All GRIMM spectrometers have a built-in service mode where different components, such as laser, pump, etc. are monitoring and reporting at all times service values via the data logger. The instrument performance can be evaluated anytime. This ensures confidence when obtaining extreme values and is thus reducing the maintenance efforts considerably.

Very little! We just recommend an annual inspection of the instruments. This is not only a significant cost saving, but also a great reduction in labour cost. Consequently our instruments are - considering the instrument's life cycle cost - the best value you can get for your money.

This abbreviation stands for Environmental Dust Monitor.

Particulate Matter, refers to all gaseous matters.

Semi-Volatile Components. These components are airborne particles that are sensitive to physical stress like heated sampling probes or flow through filters. The amount of semi-volatiles in ambient air can reach values of 69 percent of the total aerosol mass. The chemical compound of SVC are mainly Nitrates and organic components.


The Nano Division is in charge of the research, development and support of the equipment to measure airborne Nanoparticles. Most importantly, our Nano staff enables you to experience unrivalled results in precision, durability and flexibility of your measuring solution. Our systems measure in the Himalayas as well as in the jungles and deserts, on airplanes as well as on ships. Of course they also provide you with scientific data in your laboratory. Numerous comparisons have proven the reliability of this kind of measurement. GRIMM provides particle counters and sizers as well as particle generators ranging from 0.9 nm to >30 µm. Every single unit sold is fit to your personal needs and you will be advised by our specialists and by their knowledge due to our long expertise of measuring the smallest detectable aerosols.

Grimm offers as basic modules:
Detection systems: Condensation Particle Counters (CPC) and a Faraday Cup Electrometer (FCE).
Classifiers, i.e. Differential Mobility Analyzers (DMA). We offer three different DMAs to cover different particle size ranges.
A unique feature is, that any DMA can be combined with any detection system. The new software supports all combinations. You can also combine any DMA with a sampling system (electrostatic precipitator).

The Scanning Mobility Particle Sizer and Counter (SMPS+C) is an instrument for measuring size distributions of airborne Nanoparticles. It consists of a DMA and a detector (either a CPC or an FCE).

The Condensation Particle Counter (CPC), also called Condensation Nuclei Counter (CNC), is used to count individual Nanoparticles in air. The CPC enlarges the particles by condensation in order to enable the detection by an optical system.

A Differential Mobility Analyzer (DMA) classifies Nanoparticles. The applied voltage corresponds to a particle mobility (particle size) that passes through the DMA.

The Faraday Cup Electrometer measures the electric current carried by an aerosol flow. It is usually operated downstream the DMA to measure the concentrations of single charged particles.

High concentration ranges with full accuracy in single count mode (0-150,000 particles/ccm). Operable in a wide range of ambient conditions (5 - 40°C). Activation of hydrophobic and hydrophilic particles down to a size of ~4 nm. Flexible configuration (with or without pumps, with or without SMPS controller, rack version or stand-alone). Comprehensive monitoring of instrument parameters to guarantee most reliable data

Three simple, but convincing facts: It is the only mobile high precision counter on the market, it is battery powered, and it is also extendable to a complete SMPS system.

For a classical radioactive bipolar charger, charging probabilities do not depend on instrument parameters and the charger is considered as reference. The theoretical charging probabilities are well known and the unwanted contribution of multiple charged particles is low. Consequently, the calculated size distributions feature highest accuracy. A neutralizer using Am241 needs almost no maintenance and features a lifetime of many years.

This depends on the concentration range of the size distribution to be measured. The tresholds are roughly:
SMPS+E: ~104 - 108 cm3
SMPS+C (with CPC 541x) : ~102 - 107 cm3
SMPS+C (with CPC 5403) : ~102 - 106 cm3

An SMPS+E is normally used for emission measurements, an SMPS+C for measurements in ambient air. If your concentration range allows both SMPS+C and SMPS+E, consider the following advantages of an SMPS+E:

• More flexible size range due to the variable sheath air.
• Adjustable concentration range due to variable sample air.
• No consumables needed.
• Faster scan time (> ~1 min as compared to ~2 min for the SMPS+C).
• Cheaper (Contact your dealer).

YES. However, such high concentrations have to be diluted before measuring. Therefore we developed the ESS hot gas dilution system with a dilution ratio of 1:10 or 1:100 at sample air flow of 1 l/pm.

YES, with the FAPES instrument. It is particularly designed for emission measurements with an integrated diluter and requires only a minimum concentration of ~104 cm3. Contact the Grimm office for further information.

The GRIMM Universal Nano Software calculates number-, surface-, and mass size distributions and for each type of distribution a variety of statistical data: Total concentration, mode diameter, median diameter, arithmetic and geometric mean diameter, diameter of mean surface and mean mass. The correction of CPC efficiency, DMA efficiency, and multiple charged particles can be switched on or off. The data can be easily exported as text files or as spreadsheet files.

YES, GRIMM offers mobile versions of the CPC and the SMPS which feature the same technical highlights and advantages like the stationary instruments.

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