I just got a Zeagle Slimline pressure gauge and there is a rattling noise inside when I shake it. Like a loose spring or something. I haven't got a chance to try it yet, but wonder if it's normal? I don't recon any noise from any of my other gauges (Mares, Tusa, US Divers), which are way bigger than this one. Could that be because it is "miniature" and brass?