Dave, my 2dry is 6 years old and still doing just fine and has been dropped plenty of times. Would it break if I dropped it a lot, sure. So would a VR3. Treat your gear nice and it will be nice to you. Also, it is well known that the older single jeweled movements were more fragile, just like the MK 2dry, also single movement, but in a metal housing. The new Prism 2dry is double movment and lighter than the MK 2dry and so more durable, they are an improvement. The digi ones are nice, but they are more expensive, need a battery, have a batery compartment/another seal, need to be turned on...





I'm well aware that there's a spring on the needle and a weight. And the needle always drops back to 0 at the same rate because it's no longer under load. So I think you're half right. But it's the current coming off the cell that drives the needle up to the PO2 when the circuit is completed, which is why it does not rise from 0 at the same rate everytime and will give an indication of sensor output by the speed at which it climbs to the PO2. The sensor is additonally loaded by driving the needle and reflects this. And all this happens without having to wait for the solenoid to inject or having to do a dil flush. As I said, if there's some other explanation for what I'm seeing, everytime I watch the needle climb at a slower rate for the older sensors, I'd be glad to entertain the notion.