PM10 / PM2.5 Dichotomous Sampler

PM10 / PM2.5 Dichotomous Sampler Overview

The "dichot" operates at a flow rate of 16.7 lpm (1 cmh) and is available with a built-in electronic digital programmable timer or mechanical 7-day skip timer. Separate control and sampling modules allow for flexibility in deployment.

The weather-resistant control module houses the diaphragm vacuum pump, precision flow meters, flow selector valves, vacuum gauges, flow controller and flow recorder. The PM10 inlet and virtual impactor of the sampling module ensure accurate particulate collection.

APPLICATIONS

• PM10 compliance monitoring
• PM2.5 fine particulate sampling
• Source discrimination
• Visibility monitoring
• No filter artifact formation
• XRF and complete elemental analysis

PM10 / PM2.5 Dichotomous Sampler Specifications

Inlet Collection Efficiency	Cut-point within 10±1 micron over wind speed of 2 to 24 kph
Elapsed Time Indicator	xxxx.xx hours
Vacuum Gauges	0 to 30in Hg vacuum
Environmental	Meets EPA requirements; -20 to 40°C, 600 to 800 mm Hg
Exterior Materials	Aluminum; anodized
Power Required	100/115 VAC ±10%, 50/60Hz, 8 amp max; 230 VAC ±10%, 50Hz, 5 amp max
Overall Dimensions - Control Module	16" H x 22" W x 11" D (41cm x 56cm x 28cm)
Sampling Module	64" H x 30" dia. tripod base bolt circle (162cm x 76cm)
Net Weight	Control Module - 60 lbs (27 kg)Sampling Module - 20 lbs (9 kg)
Mechanical Timer	7-day timer, fully adjustable start & stop times in 15 minute intervals; ±30 min. accuracy
Digital / Timer Programmer	All functions digital and quartz crystal controlled; ±2 min/wk accuracy
Constant Flow Controller	±5% accuracy at 1 cmh over pressure drop range of 0 to 35 cm Hg across fine particle filter; has
Virtual Impactor Collection Efficiency	Cut-point is 2.5 microns
Virtual Impactor Internal Losses	Maximum value over range of 0 to 10 microns is < 2%
Flow Rate	Total flow: 16.7 lpm (1 cmh)Fine particle flow: 15.0 lpm (0.9 cmh)Coarse particle flow:
Filter Media	37 mm dia. Teflon
Filter Holder Cassette	Polypropylene, 44.5 mm O.D.
Flow Meters	±3% accuracy at above flows
Flow Event Recorder	Pressure transducer type, 24-hour, 10 cm (4
Vacuum Pump	Diaphragm type, brushless motor, clean exhaust
Total Shipping Weight	90 lbs (41 kg)

PM10 / PM2.5 Dichotomous Sampler Design

The design of the PM10 inlet allows only particles smaller than 10 microns to enter the virtual impactor, where they are accelerated at sufficient velocity to impact the particles larger than 2.5 microns into the virtual impactor receiver tube. These coarse particles impact through a void or "virtual" surface rather than onto a hard surface. The receiver tube has a flow rate of 1.67 lpm (0.1 cmh) for collection of the coarse particles; while the fine particles, less than 2.5 microns, follow a flow of 15 lpm (0.9 cmh) to the fine particle filter.

PM10 / PM2.5 Dichotomous Sampler Features

• PM10 Inlet extensively tested and recognized as the standard for PM10 low volume sampling
• Virtual impactor is EPA single stage design with 2.5 micron cutpoint
• Precision flow rates, precision machining of the virtual impactor and a high-performance flow controller mean accurate PM10 & PM2.5 data
• Filter holders clearly marked "Coarse" & "Fine"
• Flow rates easily audited by a total flow audit adapter connected to an external low pressure reference flow device
• Automatic sample termination when proper flow levels cannot be maintained