How to perform a compression test?

[the_GTI_new_guy]

Got me a compression tester. (Just a cheap thing from ebay but should be fine) No instructions with it though. Can someone give me instruction on what to do with it? I think i know what to do but dont want to bugger it up. My guess would be remove plug to be tested. Screw in meter, Remove middle ht lead at coil to stop spark. Turn engine over for a few times (about half douzen i gues, just till reading stabilises) Repeat on other cylinders.
Just say spot on and i am happy man. 
Cheers guys

[Mr Blue]

Think you hold the throttle fully open.

As long as the readings are roughly the same then thats fine.
Just take out all the spark plugs to speed things up a little. Make sure you cover the holes with some cloth or you will get sh!t in your face

In a wet compression test you put a few drops of oil down the spark plug hole and then do the compression test. Cant remember the reason why they do that coz im f**king tired and its 12:43am

[richandhazel]

yes thats basicaly it. As long as the readings are roughly the same then thats fine.
I just take out all the spark plugs to speed things up a little. Make sure you cover the holes with some cloth or you will get sh!t in your face

In a wet compression test you put a few drops of oil down the spark plug hole and then do the compression test. Cant remember the reason why they do that coz im f**king tired and its 12:43am

Doing a dry and then wet test helps to identify cause of loss of compression. If compression increases dramatically with wet test then rings are worn.