Oh dear, I'm sorry, I'm not very clever with the internet.
I'm using a Sanitas machine, sold by Lidl, German make, all looks very professional.
I understand about the depth settings and have it set on the highest (deepest) setting. Once I was successful, and having got a reading of 5.9, thought I had better keep monitoring it. I see people talking about a separate lancet and doing it by hand, but I'm not sure I have the guts for that!
I have small thin veins all over the surface of the backs of my hands, should I use one of them?
Thank you so much for noticing my post and replying.