FAQ Enviro
Frequently Asked Questions at GRIMM - Environmental |
FAQ IAQ FAQ NANO |
Aerosol Spectrometers for Environmental use
What is ENVIRO (our environmental department)?
How does our ENVIRO equipment work?
Why do I need a multi-channel GRIMM Aerosol Spectrometer when I already have a Nephelometer?
Can I measure several PM masses optically in real-time?
Is this method OFFICIALLY approved?
Can AEROSOL SIZE & COUNT distribution be determined in addition to the PM values?
How is the MOISTURE COMPENSATION done?
Can METEROLOGICAL values be determined in addition to the PM?
Can the SVC FRACTION be determined in addition to the PM values?
Can the NANO particles also be monitored?
Can GAS CONCENTRATIONS be determined in addition to the PM?
How are all these MONITORING DATA be collected and transferred?
Can the results be determined via SOFTWARE?
Can the INSTRUMENT PERFORMANCE be evaluated if the unit is installed remotely in the field?
How much MAINTENANCE is needed with the GRIMM dust monitors in the field?
What is ENVIRO (our environmental department)?
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. FAQ
How does our ENVIRO equipment work?
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. FAQ
Why do I need a multi-channel GRIMM Aerosol Spectrometer when I already have a Nephelometer?
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. FAQ
Can I measure several PM masses optically in real-time?
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. FAQ
Is this method OFFICIALLY approved?
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. FAQ
Can AEROSOL SIZE & COUNT distribution be determined in addition to the PM values?
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.
FAQ
How is the MOISTURE COMPENSATION done?
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. FAQ
Can METEROLOGICAL values be determined in addition to the PM?
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. FAQ
Can the SVC FRACTION be determined in addition to the PM values?
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. FAQ
Can the NANO particles also be monitored?
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. FAQ
Can GAS CONCENTRATIONS be determined in addition to the PM?
YES, any approved gas sensor can be combined with our dust monitors by using our data logger system inside an environmental shelter. For more details see DATA LOGGER. In some industrial applications there is no need for approved sensors. For these applications we have a range of more simple gas sensors for our mini-shelters, model EDM365, so processes can be monitored every minute. FAQ
How are all these MONITORING DATA collected and transferred?
The GRIMM DATA LOGGER.
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. FAQ
Can the results be determined via SOFTWARE?
YES. All GRIMM spectrometers have an RS-232 interface and 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. FAQ
Can the INSTRUMENT PERFORMANCE be evaluated if the unit is installed remotely in the field?
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. FAQ
How much MAINTENANCE is needed with the GRIMM dust monitors in the field?
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. FAQ
What is EDM?
This abbreviation means Environmental Dust Monitor, the leading optical dust monitoring system invented by Grimm Aerosol Technik GmbH & Co. KG, the creator of milestones in aerosol measurement for 30 years. FAQ
What is PM?
Particulate Matter, refers to all gaseous matters. We of GRIMM Aerosol Technik develop measuring devices for airborne particles down to the size of 1 nanometer. FAQ
What is SVC?
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. FAQ
