What is an IP Rating?

One common added feature for electronic thermometers, particularly electronic cooking thermometers, is a splashproof or waterproof rating.

The International Electrotechnical Commission (IEC) has created a standard for rating instruments based on their ability to protect their electronic components from corrosion by water or dust. The International Protection Rating code (or IP code) consists of the letters "IP" followed by two numbers.

The first number tells you how protected an instrument's electronics are from penetration by solids (like dust) and the second number tells you how they stand up against liquids according to the following table:

 First number
Protection against solid objects
 Second Number
Protection against liquids
0No protection0No protection
1Protected against solids objects over 50mm (e.g. accidental touch by hands)1Protected against vertically falling drops of water
2Protected against solids objects over 12mm (e.g. fingers)2Protected against direct sprays up to 15° from the vertical
3Protected against solids objects over 2.5mm (e.g. tools and wires)3Protected against direct sprays up to 60° from the vertical
4Protected against solids objects over 1mm (e.g. tools, wires and small wires)4Protected against sprays from all directions - limited ingress permitted
5Protected against dust - limited ingress (no harmful deposit)5Protected against low pressure jets of water from all directions - limited ingress permitted
6Totally protected against dust6Protected against strong jets of water e.g. for use on shipdecks - limited ingress permitted
  7Protected against the effects of temporary immersion between 15cm and 1m. Duration of test 30 minutes
  8Protected against long periods of immersion under pressure

If, for example, a thermometer had a rating of "IP65," that would mean that it was tested and found completely protected against dust as well as protected against low pressure jets of liquid from all sides, but NOT protected against immersion, or an accidental drop into the soup!