IP Ratings Explained

What is an IP Rating?

An IP rating is a 4 digit code that gives an indication to the level of protection an instrument provides against foreign bodies. This includes intrusion from solid particles such as dust and liquids such as water. 'IP rating' is often interpreted as both 'Ingress Protection' and 'International Protection' rating with both interpretations being interchangeable. IP Ratings are defined in international standard EN 60529 (British BS EN 60529:1992, European IEC 60509:1989).

What do the Numbers in an IP rating mean?

An IP code is fairly simple to decipher. Every IP code is made up of the prefix IP followed by 2 digits. These digits are largely unrelated to each other. The first digit indicates the level of protection the instrument / item has from foreign bodies. The term foreign bodies incorporates all solid items. This could be something as big as hand or something as small as a dust particle. The second digit gives an indication to the level of resistance to water ingress. This ranges from being able to withstand a simple drip of water to resistance to powerful water jets.

You can understand the full range of IP ranges by referencing the guides below. Please note, an X normally indicates that no protection rating is provided but has been used in our tables as a default value.

Solid Particle Protection - Digit 1: IP-'X'X

• 0 - No protection is provided against any contact or ingress of objects.
• 1 - Protected against intrusion of any surface or item larger than 50mm. Internal Protection not guaranteed against deliberate contact.
• 2 - Protected against any item larger than 12.5mm. This includes body parts such as fingers.
• 3 - Protected against any items larger than 2.5mm. This provides protection from most tools or larger diameter wires.4 - Protected against anything larger than 1mm. This includes most bugs, most wires, and even small screws and nails.
• 5 - Protected against any level of dust that could interfere with the satisfactory operation of the unit. This does not mean the unit it dust tight.
• 6 - Completely dust tight. A vacuum is applied with long testing durations.

Water Ingress Protection - Digit 2: IP-X'X'

• 0 - No protection is provided against any water ingress.
• 1 - Vertically dripping water shall have no harmful effect when the instrument is in an upright position.
• 2 - Vertically dripping water shall have no harmful effect when the instrument is at an angle of 15° from its normal position.
• 3 - Spraying water at an angle of up to 60° shall have no harmful effect
• 4 - Splashing water against the instrument from any direction shall have no harmful effect.
• 5 - Water jets projected by a nozzle against the instrument from any direction will have no harmful effects
• 6 - Powerful Water jects projected by a nozzle against the instrument shall have no harmful effects.
• 7 - The instrument can be immersed in water up to a depth of 1m. Specific requirements should be outlined by the manufacturer.
• 8 - The instrument is suitable for continuous immersion in water. Specific requirements should be outlined by the manufacturer.

Common IP Ratings in Test & Measurement Instrumentation

Unfortunately not all manufacturers supply their equipment with IP ratings. A common theme is to see IP ratings supplied when the product surpasses ratings of around IP-54. This is the level that dust ingress is prevented and a sufficient level of splash proofing is supplied for it to become a notable / sellable feature of the instrument.

The best advice we can give is that if you need guaranteed water or dust protection. Make sure you locate the IP rating of the instrument before purchase!