The South Australian Spelling Test has been around for a number of years and is a staple of nearly all Australian primary and early secondary teachers assessment schedule.
The test consists of 70 words and when completed allows the teacher to generate a spelling age for that student based upon their score.
It is a great tool for quickly identifying students who need assistance with their spelling skills.
The test and it's complete instructions can be downloaded here.
It takes around 15 minutes to administer to a class.