The AeroTrak™ 9310/9510 is a portable particle counter that meets all the requirements of ISO 21501-4. Calibration is carried out using an internal pulse height analyser. Due to the large touch-screen interface and the clear firmware structure, operation of this particle counter is made simple. The 0.3µm device version from the particle counter AeroTrak™ series works with a flow rate of 1 cfm (28.3 L/min). The six sampling channels of the AeroTrak 9310 has a particle size range down to 0.3µm and up to 25µm. Cleanroom sensors for temperature, humidity and air velocity can be integrated into the particle measurement to enhance continuous environmental monitoring.