What are the IP Ratings quoted in some specifications?

IP rating stands for ‘Ingress Protection’ and is an internationally recognised standard used to show the level of protection given by enclosures around electronic equipment against the penetration of water and dust.
The IP number is shown as IPXY where X is the level of protection against dust and Y is the level of protection against water. The higher each number the better the protection so IP65 will give better protection than IP54 against both dust and water.

First Number (X) Protection Against Solids

0- No protection.

1- Protected against solids up to 50mm.

2- Protected against solids up to 12mm.

3- Protected against solids up to 2.5mm.

4- Protected against solids up to 1mm.

5- Protected against dust, limited ingress permitted.

6- Totally protected against ingress of dust.

Second Number (Y) Protection Against Water

0- No protection.

1- Protected against vertical falling drops of water. Limited ingress permitted.

2- Protected against direct sprays of water up to 15 degrees from vertical. Limited ingress permitted.

3- Protected against direct sprays of water up to 60 degrees from vertical. Limited ingress permitted.

4- Protected against direct sprays of water from all directions. Limited ingress permitted.

5- Protected against low pressure jets of water from all directions. Limited ingress permitted.

6- Protected against high pressure jets of water.

7- Protected against temporary immersion up to 1 metre.

8- Protected for longer periods of immersion under pressure.

IMPORTANT NOTE

An IP rating, no matter how good, does not mean the radio is intrinsically safe as no protection is provided for use in explosive atmospheres unless a unit is also ATEX approved.