Waterproofing is measured in terms of resistance to water pressure in terms of atmospheres (ATM). The higher the ATM, the greater the resistance to water pressure. It is important to note that waterproofing is different from water resistance. Water resistance measures how well a device can withstand exposure to water, but it does not necessarily mean that the device is waterproof. On the other hand, waterproofing means that the device is designed to be used in water and can withstand being submerged in water.