Water Purity Test Pen

An electronic pen that can test the water you drink

Product

Water Purity Test Pen

Promise

A small electronic pen that identifies the quality of drinking water within three seconds, tests the degree of pollution and the irons, bacterium and toxic elements. It claims to be 'sensitive to such toxins as cyanide, arsenic, mercury, lead, pathogenic virus' and all other kinds of other horrible creatures.

Performance

A pen... that can tell you if you're going to die from drinking contaminated river water? Too good to be true, right? Well, we road-tested this one quite extensively, as you can imagine. First of all, we took a glass of tap water and a glass of filtered tap water. The litmus test is the magic number 200 - above that and you shouldn't drink it. Between 100 and 200, it's okay. And below 100, it's really good stuff. We also dunked it in the lake just to make doubly sure this thing really worked.

Verdict

Lake water: 360 (a no go)

Tap water: 130 (not bad)

Filtered tap water: 60 (the elixir of life)

For 20 quid, this thing is amazing. And to save you the trouble (because we know you'd do this too) we tried it out in a pint of beer. Undrinkable apparently.