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.
However, the maximum submersion depth of such an instrument is not specified. This makes total sense because there is a huge difference between submersing an instrument in a 1 m high water tank or using an instrument for measurements in a depth of 300 m on the ocean ground. According to the standard, the manufacturer and the user must therefore agree on the exact specification for IP68. Anyway, the IP68 rating must always be better than the IP67 rating, that means that the instrument may be submersed for at least 1 m.
In practice, it results in totally different immersion depths for our pressure transmitters and level probes depending on the area of application. The immersion depths range from 3 m to 300 m maximum. I.e. completely different submersion depths are specified for the same IP rating but depending on the application.
If you are looking for the suitable solution for your application, just ask your contact person for advice.
For more information please see our article “Definition of IP protection types“
Definition of the IP68 rating in theory and practice,