One of the most harmful airborne pollutants with respect to human health is particulate matter. Air particle counters are used to determine the air quality by counting and sizing the number of particles in the air. This information is useful in determining the amount of particles inside a building or in the ambient air. It is also useful in understanding the cleanliness level in a controlled environment. Ai ...

Today I will show a very simple ionization chamber that can detect radioactivity. I was able to detect with it ionizing radiation from a smoke detector (Am241 isotope). It's also immune to electromagnetic interference (EMI) due to a good shielding. This device doesn't explicitly use any power supply. It's connected to a multimeter set to measure resistance, in this mode, the multimeter provides a small volt ...