If you have an iPhone, you might want to also check this "Space Clock" out as a sand timer replacement. It's free to boot!
Thanks for the heads up. Only a few games in to playing Space Hulk (at least in the last 20 years or so) and I think this is exactly what I need to make sure the pressure is kept on me. (When roles reverse and it's my partner's turn for Space Marines I have chosen to not push for the use of the timer until she asks for it. I am just grateful she is enjoying the game without it at this point).