Removing and replacing keys on Acer Aspire laptop's keyboard may require a small screwdriver for precision. Keyboard keys of Acer laptops designed for easy removal and replacement.
How to Measure Air Pollution for a Science Fair Project. Pollution is one among the major problems of todayâs world and air pollution is one root cause of many environmental issues. You can use a magnifying glass for this purpose as the dust particles are too tiny to be seen with necked eye. 2  Count the number of dust particles carefully stuck to the Vaseline in each square and note them down on a note book. 3  Use the number of dust particles sticked to the squares as a proof of air pollution.
In words, itâs this simple: CADR is a measure of an air purifierâs ability to produce pollutant-free air. That measurement is expressed as a certain number of cubic feet per minute. That is, the CADR essentially states the volume of clean air a portable air cleaner can produce in a given time. For example, suppose a particular model has a CADR of 250 for dust. That means the unit can reduce dust particle concentration equivalent to adding 250 cubic feet per minute of dust-free air.