PCI Ion density needs to be above 7000pcs/cm3 to sanitize the indoor air effectively. How to monitor the positive an negative Ion density in your place? Sharp Singapore developed a demo with partner to monitor the Ion density. The color code shows the Ion density. Red and orange color means Ion density is not enough. Green color means the Ion density is above 7000pcs/cm3 and enough to sanitize the air effectively. The users can easily tell from the PCI Ion density in this demo.