What is a PM2.5 high volume air sampler?
The Tisch Environmental PM2.5 high volume air sampler is a non-Federal Reference Method sampler for the collection of particulate matter that is 2.5µm or less. Its primary uses is for non regulatory sampling and institutional studies. The PM2.5 size selective inlet is made up of 40 stainless steel nozzles that allow only 2.5µm particulates to get deposited on the filter. PM2.5 particulates are particularly hazardous to your health as they can work their way into your lungs during respiration and can be absorbed into the bloodstream.
How does a PM2.5 sampler work?
The PM2.5 high volume air sampler collects particulates at a flow rate between 36-60 cfm through a PM2.5 size selective inlet. As the particulates travel through the size selective inlet the larger particulates are trapped inside of the inlet as the smaller PM2.5 particulates continue to travel through the PM2.5 inlet and are collected on the 8″ x 10″ quartz filter paper. This quartz filter is weighed previously to sampling and after the sampling to determine the mass of particulates that are smaller than 2.5 microns. The flow rate on this instrument is controlled by either a mass flow controller, a volumetric flow controller or the Tisch Environmental PLUS technology electronic flow controller. Tisch Environmental offers a wide range of PM2.5 samplers with several different options to fit every custom sampling installation.
Instrument Components
PM2.5 particulate samplers are built with the same basic components. A motor, timer, flow controller, elapsed time indicator, outdoor aluminum shelter, and pressure recorder. Tisch Environmental uses only high quality components to ensure reliability and consistency. We offer a variety of options to give the user flexibility and to fit every unique sampling installation.
Flow Controller
Mass Flow Controlled(MFC): The Mass Flow Controller uses a hot wire anemometer to maintain a steady flow rate throughout the sampling period. The hot wire anemometer is inserted into the flow channel and detects changes in thermal mass to increase or decrease the motor speed.
Volumetric Flow Controlled(VFC): The VFC controller is a critical orifice with a predetermined hole diameter. The critical orifice is calibrated in a NIST traceable lab to determine the volumetric flow rate. The motor runs wide open and as air passes through the critical orifice,the sampler runs at a predetermined flow rate.
PLUS Technology (MFC): The PLUS technology MFC uses ambient temperature, ambient pressure, and a hot wire anemometer to maintain the set flow rate. This is the most accurate flow controller available. It also features and auto calibration function and digital timer.
PLUS Technology (VFC): The Plus Technology volumetric flow controller uses a combination of the critical orifice and the PLUS controller to calculate the ambient flow rate. The system uses the temperature, barometric pressure, and orifice pressure to calculate and record the ambient flow rate. The system also includes a digital timer.
Outdoor Shelter
Aluminum Outdoor Shelter: PM2.5 high volume air samplers are housed in an anodized aluminum shelter. The shelter is designed to allow particulate matter to by drawn on to the filter from all directions. The rugged construction of the outdoor enclosure allows it to withstand the elements with minimal maintenance.
Motor Type
Brush Style Motor: Brush Style motors use carbon motor brushes to conduct current within the electric motor. They are low cost but require routine motor brush changes.
Brushless Style Motor: motors do not use motor brushes or require maintenance. They are higher in cost and do not have any emissions.
Pressure Recorder
Dickson Chart Recorder: The Dickson chart recorder is a 4″ pressure cart recorder that records pressure variations over a 24 hour period. The chart recorder is attached to the motor back pressure and records the pressure on the 4″ recorder chart.
Timer Style
7-Day Mechanical Timer: Recognized by its bright yellow timer dial, the 7 day mechanical timer uses a series of on/off trippers to set the sampling schedule.
Digital Timer: Recommended by the US EPA, the digital timer allows for 1 in 3, 1 in 6, 1 in 7, and custom sampling schedules. Its internal battery backup ensures that the timer will not have to be reset after a power failure. It also includes an LCD screen and soft press buttons for easy use.
Elapsed Time Indicator
Elapsed Time Indicator: The elapsed time indicator is a mechanical clock the counts the hour and minutes that the instrument is actively collecting a sample. This device is used to track motor life, motor brusch changes, and to verify the sampling time.
