DMT - Model PAX -Photoacoustic Extinctiometer

Direct In-situ Measurements

Get accurate measurements for both light absorption and scattering in a single instrument. Then correlate the absorption measurement black carbon mass concentration.

Seamless efficiency

Get continuous and autonomous operation, with no filter collection required and no filter data artifacts.

Real-time results

Count on fast response, one-second resolution, and real-time data display on a high-resolution touch screen.

Tech-enabled sensitivity

Achieve excellent scattering coefficient sensitivity with reciprocal nephelometry.

Advanced Versatility

Select from four wavelengths (870 nm [standard], optional 405 nm, or 532 nm), and get wide dynamic range suitable for pristine regions to source sampling.

• Visibility & Fog Studies
• Human Health

• Measured Parameters: 
• Absorption coefficient, Babs
• Scattering coefficient, Bscat
• Auxiliary Parameters: 
• Temperature
• Pressure
• Relative Humidity
• Derived Parameters: 
• Black carbon (BC) mass
• Extinction coefficient, Bext
• Single scattering albedo, SSA
• Dew Point
• Measurement Range – Absorption and Scattering: < 1 Mm-1 – 10,000 Mm-1 (870 nm, 60 sec. averaging)
• Laser:
• 870 nm (1.4 W)
• Modulation Frequency: 1500 Hz nominal, square wave
• Angular Integration for Scattering: 6° to 174°
• Sample Flow:
• 1 L/min
• Flow Control: Critical orifice
• Diaphragm Pump
• Response Time: < 10 sec; one-second resolution
• Data Averaging Time: 1, 10 or 60 seconds, user selectable
• Zero Check: On demand, or automated at user selectable interval at 5, 15, 20, 30, or 60 minutes. Zero check with high-efficiency filtered air sample.
• Front Panel Features: 
• Graphical color touch-panel display screen
• Two USB-A ports
• Power switch
• User interface via touch screen or standard keyboard
• Rear Panel Connections: 
• Sample inlet (compression fitting for ¼” tube)
• Pump exhaust (compression fitting for ¼” tube)
• AC and DC power connections
• Serial RS-232 jack
• Ethernet port
• Two analog BNC inputs
• Four analog BNC outputs
• Data Storage Capacity: > 200 days
• Communications Output: Ethernet 100/10 Mbps, RS-232 Serial
• Power Requirements: 90 – 264 V, 47 – 63 Hz (AC Power) or 12 VDC Power Consumption 45 W
• Dimensions: 18 cm H x 48 cm W x 61 cm D (7″ H x 19″ W x 24″ D); rack mountable
• Weight: 18 kg (40 lb)
• Environmental Operating Conditions: 
• Temperature: 0 – 40°C (32 – 104°F)
• RH: 0 – 90% RH non-condensing
• Computer Requirements for PMC Software (Computer not included): 
• Windows XP, Vista, or Windows 7
• Minimum 1GB RAM

• Hard-shell shipping case suitable for frequent travel
• PM 1.0 cyclone inlet (1 liter/min) for particle size selection
• PM 2.5 cyclone inlet (1 liter/min) for particle size selection

The Lifecycle Care Program ensures PAX integrity and performance vital to your research mission for 3 years or 3 calls (whichever comes first). When conducting complex and time intensive laboratory or field measurements it is critical to avoid down time, and ensure data collection accuracy. The program consists of 3 key deliverables for each year or call:

• Instrument Logistics
• Instrument Integrity
• Instrument Performance

Lifecycle Care Program Includes:

LOGISTICS

• Shipping to and from Droplet Measurement Technologies facility
• Customs handling, including CARNET ATA if required

INTEGRITY

• Incoming instrument evaluation and health check

PERFORMANCE

• Software and firmware validation
• 100%-unit functionality test
• Calibration data
• Calibration report
• Certificate of calibration

At times, our technician might discover an instrument issue, which might not be covered by the Lifecycle Care Program or by our product warranty. In such case we will reach out to you with a service & repair estimate to allow you to provide us with the next steps of action.