Following is the international waterproof specifications specified on instruments and equipment.
MIL-STD 810 Immersion Standard, Military Specification equipment
MIL-STD 810 Blowing Rain, Military Specification equipment
JIS 2-8 Japanese Water Protection Specs similar to IEC529
CFR Title 46 Part 110.15 Aircraft Civilian specifications
IEC 529 European (ECC) water protection specifications
Of these, only IEC 529 (European Community Specification) and JIS2-8 (Japanese Industry Standard) have graduated test levels. These two specifications are very similar, but IEC 529 is gaining more acceptance in Europe which is a major market for many US manufacturers and is more defined in terms of the actual test. The table below gives a summary of the requirements for IEC 529 for WATER PROTECTION PROVISIONS.
Test Level Definition
No special protection
Protected against falling water Equivalent to 3-5mm rainfall per minute for a duration of 10 minutes. Unit is placed in its normal operating position.
Protected against falling water when tilted up to 15 degrees - Same as IPX-1 but unit is tested in 4 fixed positions - tilted 15 degrees in each direction from normal operating position.
Protected against spraying water - Water spraying up to 60 degrees from vertical at 10 liters/min at a pressure of 80-100kN/m2 for 5 min.
Protected against splashing water - Same as IPX-3 but water is sprayed at all angles.
Protected against water jets - Water projected at all angles through a 6.3mm nozzle at a flow rate of 12.5 liters/min at a pressure of 30kN/m2 for 3 minutes from a distance of 3 meters.
Protected against heavy seas - Water projected at all angles through a 12.5mm nozzle at a flow rate of 100 liters/min at a pressure of 100kN/m2 for 3 minutes from a distance of 3 meters.
Protected against water immersion - Immersion for 30 minutes at a depth of 1 meter.
Protected against water submersion - The equipment is suitable for continual submersion in water under conditions which are identified by the manufacturer.
*Note: IEC 529 level 7 is designated "IPX7" and is equivalent to JIS 7.
What is an IP Rating?
When you buy electrical equipment, you may find it has an "IP rating". This tells you how resistant it is to dust, liquids and impacts. Clearly this is important when buying electronics for a RIB and so on. The IP Rating is a simple encoding that covers a range of international standards for enclosures and electrical switchgear up to 1000V a.c. and 1200V d.c.
What is the Rating Code?
You'll often see brochures say the equipment is rated to "IP54" or "IP65" and so on. This is a short form more commonly used in Britain. The full international version has three digits after the IP rather than two, e.g. "IP653". Each digit represents the degree of protection against one of the environmental factors. The first is for solid particle ingress, the second is for liquids ingress, and the third is impact resistance. The meanings of the numbers are given in the following table.
What do the IP Numbers Mean?
|First Number (Dust)||Second Number (Fluid)||Third Number (Impact)|
|#||Protection against...||#||Protection against...||#||Protection against...|
|0||No Protection||0||No Protection||0||No Protection|
|1||Solid objects over 50mm, e.g. accidental touch by hands||1||Vertically falling drops of water||1||Impact of 0.225 Joule (150g weight dropped from 15cm)|
|2||Solid objects over 12mm, e.g. fingers||2||Direct sprays of water up to 15° from the vertical||2||Impact of 0.375 Joule (250g weight dropped from 15cm)|
|3||Solid objects over 2.5mm, e.g. tools & wires||3||Sprays up to 60° from the vertical||3||Impact of 0.5 Joule (250g weight dropped from 20cm)|
|4||Solid objects over 1mm, e.g. small wires||4||Water sprayed from all direction - limited ingress permitted||4||(No meaning)|
|5||Dust - limited ingress (no harmful deposits)||5||Low pressure jets of water from all direction - limited ingress permitted||5||Impact of 2.0 Joule (500g weight dropped from 40cm)|
|6||Dust - total; no ingress||6||Strong jets of water from all direction - limited ingress permitted||6||(No meaning)|
|7||Immersion between 15cm and 1m||7||Impact of 6.0 Joule (1.5Kg weight dropped from 40cm)|
|8||Long periods of immersion under pressure||8||(No meaning)|
|9||Impact of 6.0 Joule (5Kg weight dropped from 40cm)|