hi when we keep records of growth and development it is very important that the scl straight carapace length and of course the weight is measured and recorded accurately.i prefer to use digital scales as you can get these relatively cheaply and most are accurate.measuring your tortoise is a different thing and everyone seems to have their own idea how to do it .i often hear people say every time i measure my tortoise i get a different length and this all on the same day lol.the simplest and cheapest way is to place your tortoise head first against the wall standing on a piece of paper or cardboard .then gently push him/her against the wall until the head retracts completely,while holding them firmly make a mark with a pencil level with the rear of the carapace then quickly release the poor confused tortoise.you can now measure the distance from your mark to the wall.this should give you an accurate recore for future referance to see how you tortoise is gowing and of course you can also compare their weight to length ratio to ensure they arent underweight pre hibernation.there are devices to measure tortoises scl but this is certainly the cheapest method and just as accurate.i have a few to measure and check myself so have made a tool for this that saves me a lot of time.
terry

Excellent, thank you Terry, I've been using my new 'measure thingy' and it's great. I think the most important thing is to stick to the same method - use the same bit of wall (for example) to measure them against, this way whether its accurate or not it will be consistant (if you get my drift?? )