How exactly is the device calibrated (i.e. can you explain in detail the procedure?)
Calibration Procedure: The Haz-Dust™ instrument to be calibrated is zeroed to the Master Unit by using a Zeroing Filter also called a Clean Air Filter. The filter removes particulates thus dispensing clean air.
The device is calibrated against the Master Unit. (The Master Unit complies with regulations requiring the device to be sent annually to an outside lab for calibration).Once units have been zeroed, ISO12103-1 A2 Test Dust (Arizona Road Dust) is put into a Dust Chamber. Compressed air is pushed into the chamber stirring the dust. The dust is then drawn through a Dore-Oliver Cyclone, separating out the respisrable dust.
The respirable dust is pumped through tubing before entering the Master Unit. The sensors for the both the Master Unit and Calibrated device are locked together. Both sensors should receive similar readings. If the numbers are not exact the unit to be calibrated is adjusted to match the Mater unit. Three data point are plotted not including the zero plot. Once the air is passed through the sensor it continues through tubing before being displaced by a clean air filter.