Old Princeton Tectonics Bottom Timer

[Smiling Dragon]

Just got one of these included with a set of depth and contents guages via online auction. It's all a bit scratched and banged but seems to be in working order.

Thing is, I don't really understand bottom timers in general - I would imagine they record the time you spend on a given dive (which sounds nice) by picking up a pressure change.
Sure enough, if I press on the rubber pad on the back of this one it starts counting off seconds.

But that's where I run out of skill.

There's a knob on the top of it which I can wind like I would a watch. It turns anticlockwise and clicks so I _guess_ that's what I'm doing here too. It'd be nice to confirm this though. Can't wind it clockwise - havn't tried too hard though as I'd prefer not to break it right off the mark.

There's a spade-bit screw in the top of the 'winder knob' but for all I know that is for dismanteling the thing. Springs and cogs work better when they remain with the timer so I would prefer not to pull it apart (by mistake or on purpose) when I don't need to.

Once I stop pressing on the rubber pad, it stops timing - great, but how do I reset it again? It showed up at 0 seconds, 0 minutes so it's clearly not impossible to do...

Anyone got some insight into these things? I'd prefer not to have to squeeze the thing for an hour after each dive to have it wrap back round to 0 again

Guidance needed! Pretty please?

[scubadoguk]

pull the adjuster(you thought I was going to say knob :P) up/ or it me be push down but I remember it was upwards on mine and turn it to reset
The pressure acts on it to turn it on and I think it works at around 6 ft (2 mtrs)
and off at the same depth.

[Smiling Dragon]

Originally Posted by scubadoguk

pull the adjuster(you thought I was going to say knob :P) up/ or it me be push down but I remember it was upwards on mine and turn it to reset.

You rule! Just tried it - had to really tug on it () as it had seized a bit but it's doing it's thing perfectly now.

Magic! I now have something to go on if my puter decides to tell me fibs.

[Edit:]It gets cooler - the face had been quite badly craized <sp?> over it's life so I popped down to the watch repair shop near my work to see how much it would cost to polish it up - they did it for free for me right there in the shop! All that's left are a couple of scratches that they didn't want to polish out for fear of making the face too thin to hold pressure.
Score!

[Twinset & Wing]

Now that is service