IP Ratings Differences Explained
Published on: Jun 12, 2017
It is often difficult and confusing for engineers to know what type of rating they need to look for when they desire to have a “waterproof” enclosure. There is a big difference between waterproof, water resistant, and other but not specific certifications. To help out, there are several rating systems that have been developed by several testing agencies that verify the results. Among these, the two best known are NEMA and IP. Today will deal only with the IP system.
Able to protect against water jets
Water projected by a nozzle (6.3 mm) against enclosure from any direction shall have no harmful effects.
Test duration: at least 15 minutes
Water volume: 12.5 litres per minute
Pressure: 30 kPa at distance of 3 m
Able to protect against powerful water jets
Water projected in powerful jets (12.5 mm nozzle) against the enclosure from any direction shall have no harmful effects.
Test duration: at least 3 minutes
Water volume: 100 litres per minute
Pressure: 100 kPa at distance of 3M
Able to protect against Immersion up to 1 m Ingress of water in harmful quantity shall not be possible when the enclosure is immersed in water under defined conditions of pressure and time (up to 1 m of submersion).
Test duration: 30 minutes
Immersion at depth of at least 1 m measured at bottom of device, and at least 15 cm measured at top of device
Unfortunately, we are asked too rarely regarding the specification of the IP68 rating for our pressure sensors and submersible pressure transmitters, i.e. how deep such an instrument may be submersed. However, this is not only a very meaningful question but also a mandatory one, because, contrary to almost all other IP ratings, the IP68 rating is only described and not fully specified by means of concrete values in the IEC 60529:
- The first digit, the number “6”, means that the instrument has total dust ingress protection.
- The second digit, the number “8”, means that the instrument is suitable for permanent submersion in water. Up to 1 meter