Introduction:
Introduction: SWAM5A is an integrated automatic system operating at an ambient temperature for sequential sampling of particulate matter on a membrane filter and for measuring the particulate mass by using the beta attention method.
SWAM5A as a particulate Sampler
It’s a reference Sampler
The SWAM5A samples suspended particulate matter (PTS, PM10, PM2.5) in compliance with all technical requirements of National and International regulations (USEPA and EN123.1). As required by the regulation, it utilizes standard 47mm filter membranes that can be removed from the monitor to allow chemical-physical analyses.
Sampling head
The SWAM5A can be fitted with any sampling head operating in the flow rate range between 0.8 and 2.5m³/h, and can also be used with the following:
• Low volume EN1234.1 sampling head operating at the volumetric flow rate of 2.3m³/h, as described in the European Reference Method and in the DM60 02/04/2002. This head (FAI instruments mod. LV-PM10) is available with the SWAM5A as default configuration;
• USEPA 40 CFR part 50 sampling head operating at the volumetric flow rate of 1m³/h;
• USEPA 40 CFR part 50 sampling head equipped with a wins PM2.5 impact operating at the volumetric flow rate of 1m³/h.
A constant volumetric flow rate is automatically maintained at the head inlet by monitoring the mass flow rate at ambient temperature and pressure. The volumetric flow rate is controlled to precisely 1% of the measured value; any deviation with respect to the nominal value is available to the user during the sampling and is stored in the buffer.
Filter media
Standard 47mm filter membranes placed in easy-to-handle PVC filter housing are used in the SWAM5A. Glass fiber filter, quartz filter, Teflon filter or any other filter media can be used according to the kind of chemical analyses the user needs to perform and to the particular environmental condition.
Filter holders normally used in the SWAM5A have an exposed area (ß spot area) of 11.95 mm², it is also possible to use a filter holder with a reduced spot area of 7.07 mm² or 5.09mm² in order to increase the sensibility in cases of very low concentrations or short duration sampling.
Chemical analysis
The ability to use different types of filter media makes it easy to perform chemical analysis on the collected particles as required by the current regulations (toxic metals, arsenical, cadmium, nickel and organics-polycyclic aromatics hydrocarbons and benzoapirene).
Automatic handling of membrane filters
The SWAM5A is capable of running a 30-membrane filter (or more on demand) automatically. The filter holders are inserted into a cylindrical transparent plastic container designed to prevent any contamination by outside particulates.
At the end of each sampling and measuring the instrument moves the exposed filter into a second container that has the same sanitary conditions.
Filters can be loaded and unloaded at any time without any interruption of the operative cycle.
The sample is transferred at ambient temperature
The International regulation for reference methods states that the sample must be transferred from the sampling point to the membrane filter at ambient temperature in order to minimize the loss of air-borne compounds.
The transfer line of the SWAM5A is inserted into a coaxial tube containing ambient air to keep the temperature of the air sample as close as possible to the ambient temperature.
The temperature in the filter and the outside temperature are both monitored and this data is available to the user.
It has been developed to ensure an excellent data coverage
The SWAM5A has been developed with the specific purpose to yield an extremely high percentage of useful data. It has an unsurpassed capacity to work continuously carrying out sampling, taking measurements and yielding data without interruption.
The following features assure excellent data coverage:
High quality of the hardware avoids interruptions due to a malfunctioning;
In case of power loss the air sampling will be interrupted, but the mechanical movements and the mass measurement procedures are both kept running by the back-up battery. The battery can support the instrument for up to four hours thus avoiding any loss of data;
Routine operations such as filter substitution and automatic quality checks are carried out on-line without interfering with the operative cycle;
Filter holders erroneously inserted up-side down by the user are automatically detected and removed;
A rigorous quality assurance on the system functions are carried out automatically to obtain a complete validation of output data;
The software of the SWAM5A performs a fast fault finding procedure, the modular constriction also makes any repair very quick and easy.
Automatic quality controls:
At the beginning of each measurement cycle, a pump leak test runs automatically to check that the connection downstream of the filter is without any residual leak.
The pressure drop across the filter membrane is continuously improved, in order to evaluate the difference between the current value and the initial calibration value.
All the quality controls on the sampling procedure, measurement procedure and filter movements are available to the user in real time, and are stored in the buffer, and if necessary, can activate WARNINGS and/or ALARMS
Equivalence to the reference method:
The mass measurement is carried out through the ß attenuation technique by using a low activity C14 source (< 100 µ Curie). This method is equivalent to the reference method and performance is not dependent on the environmental condition (temperature and humidity).
Mass measurement at ambient temperature:
The measurement of the collection mass is carried out at the reference temperature cited in the International Regulation (20ºC) in cases where the SWAM5A is kept at temperature below 20 ºC, and at ambient temperature in other cases. This feature minimizes the loss of air-bone compounds that may occur when the temperature where is the instrument is kept is higher then the ambient temperature.
Mass measurement
A very high accuracy and precision of the beta mass measurement is obtained by taking into account the variables that influences the instruments responses:
· Natural radioactivity is measured and taken into account
· Temperature and pressure measurements allow it to apply a correction for the variations of the air density;
· The stability of the Geiger Muller detector is monitored and controlled.
As a beta mass measurement based on a differential technique, the SWAM5A does not require any recalibration after the first calibration carried out in the factory (FAT). If necessary it can be verified by using two reference membranes supplied with the instrument. The “beta test” program will automatically calculate the difference between the calibration factors recorded during the test and the initial calibration values obtained in the factory with the same reference membrane.
Choice of sampling mode:
The SWM5A can operate with two sampling modes specifically developed to satisfy the many needs in the field of air quality control for particulate matter.
The SINGLE FILTER MODE allows the sampling of ambient particles and the collected mass on a single filter. This mode conforms to the National and International regulatory requirements:
· Collection of a representative PMx sample over 24-hour sampling;
· Possibility to perform chemical analyses on the sample (metals, organics, etc.);
· Independent determination of the collected mass (reference gravimetric method).
The FAST MODE can be selected when users need information about the trend of the particulate mass concentration over short time periods (e.g. average two hours concentration); it allows a significant reduction of filter consumption and operating cost.
In this mode, four membrane filters undergo the sampling using the sequential, cyclical and the beta measurement steps (minimum sampling duration is two hours).
The user selects the duration of the sampling, (e.g. four hours) the filter consumption (e.g. one filter a day), and the SWAM5A will cyclically use the same four filters for a few days (in the example four days).
For the FAST MODE it is advised to use a filter holder with a ß spot of 5.19 mm²
A Safe Investment
A reliable and accurate planning of the instrument, the use of high quality materials and components, high performance, innovative solution, all make of SWAM5A a wise investment. The instrument has also been developed to keep service and/or break down time to a minimum.
· The SWAM5A can operate automatically while performing both the particulate and the beta attenuation mass measurement without any manual operation for very long periods, storing data in real-time mode.
· The SWAM5A can be remotely controlled through RS-232 serial interface, allowing the bi-directional information exchange with a pc or with a remote computer using a modem (PSTN, ISDN, GSM, GPRS). It is also possible to connect the instrument to an Internet provider by the PPP protocol. The warning and alert messages can also be sent a using an SMS message to a normal GSM or GPRS mobile phone. Using a LAN Ethernet interface the SWAM5A can be accessed via the Internet using a standard TCO/IP protocol.
· The SWAM5A has many innovative features, such as the ability to control the flow rate “at constant strokes number”, which assures the consistency of the cut point which is independent of the value of the ambient temperature.
Technical Specification Mass measurement
Mass measurement |
Mass measurement range | 0÷50mg |
Precision of the mass measurement (as RSD) | 15µg on a sigle filter mode6µg on fast mode |
| Precision of the mass concentration | ±0.3µg/m³ on sinlge filter mode (24h)±1.5µg/m³ on fast mode (24h |
| Detection limit of the mass concentration | ±1µg/m³ on sinlge filter mode (24h)±4.5µg/m³ on fast mode (24h) |
| Activity of the C14 radioactivity sourc | e <100 µCurie |
| Pneumatics | |
| N° of filter holders in the container | Max 30 (more on demand) |
| Flow rate range | 0.8-2.5 m³/h |
| Standard inlet head (conforming to EN1234.1) | Mod. LVPM10 operating at 2.3 m³ |
| Maximum pressure drop | 50Kpa at 2.3 m³/h |
Precision in the flow rate measurement
| <1% of the read value |
| Accuracy in the flow rate measurement | <2% of the read value |
Dimension of the sampler
| (L x W x H) 340x540x240 mm |
| Dimension of standard filter containers | (H x ø) 200 x 65 mm |
| Dimension of the pump module | (L x W x H) 200 x 320 x 200 mm |
| Sampler weight | 38Kg |
| Pump module weight | 10Kg |
| Power supply | 230 VAC 50-60Hz 750 watt |
