IPX is a standard given to products so you can compare them against each other – and know what level of water resistance and dust ingress they offer.
Headlamp Water Resistance Ratings and What they Mean
IPX-0 No special protection – rain can short this out.
IPX-1 Protected against falling water (rain). Equivalent to 3-5mm of rainfall per minute for a duration of 10 minutes, while headlamp is worn on head as normal.
IPX-2 Protected against rain when tilted 15° any direction from normal operating position.
IPX-3 Protected against spraying water from top. With headlamp worn on head, water spraying from 0 to 60° to the side at 10 liters per minute at a high pressure for at least 5 minutes.
IPX-4 Protected against splashing or sprayed water from any angle for some time.
IPX-5 Protected against pressurized water jets – Water projected at all angles through a 6.3mm nozzle at a flow rate of 12.5 liters/min at high pressure for 180 seconds at a distance of 3 meters.
IPX-6 Protection against water sprayed at any angle – high volumes of water for at least 180 seconds from a distance of 3 meters.
IPX-7 Protection against submersion in water. Immersion for at least 30 minutes at a depth of 1 meter.
IPX-8 Protection against submersion in water for more than 30 minutes in at least 2 meters of water. The manufacturer can choose to specify the exact conditions under which the equipment is tested and warranted against failure.
Please keep in mind that companies all over the world have a slightly different take on the ratings shown here. They may define the rating in a slightly different way.