When the pump is operated at specific sampling flow rates, the pDR-1200's optimally designed metal cyclone provides precisely defined particle size cuts. A 4 liters per minute, the cut point of the standard cyclone is 2.5 µm as required for PM2.5 monitoring. With the attachable pump module, cut points between 2.0 and 10.0 µm are achieved. Ith a larger separate pump, this range can be extended down to 1.0 µm. Aerodynamic particle size distributions can be computed using instrument readings and an algorithm provided.
The unit has an integral filter holder (for 37 mm filters) located directly downstream of the photometric sensing stage. This allows concurrent gravimetric measurements or subsequent chemical analysis of collected samples. Primary gravimetric calibration of the instrument is easily accomplished under field conditions by simply adjusting the calibration constant to coincide with the filter-determined concentration.
It has an autoranging digital output signal as well as two analog outputs (voltage and current) which can be fed a process controller for ventilation control or to a remote data processor or display. The concentration range for the analog signal can be selected using a personal computer. It also has an on-board programmable audible alarm with switched control output. The unit has large capacity data logging capability and interfaces with a PC via included software for data tabulation, graphing, etc.
The unit is powered by an internal 9V battery (24-hour duration) or is capable of running continuously and unattended from AC line current using the power supply/charger provided with the unit. The pump module operates from either an optional rechargeable NiMH battery pack or from AC line current.
Norris & Company, 960 Turnpike St., Canton, MA 02021. Tel: 781-821-8300. Fax: 781-821-8301.