Little Monkey

Cave Diving

Nora 3-dive lamps, including 3-dive battery box, are individually pressure tested to 14 bar, 130m. There is no way you are getting a look at our pressure tester, it's not pretty. We design tested an initial batch of Nora 3 lamps to 20 bar, and it groaned like a World War 2 submarine (the pressure tester, not the lamps) ........  

However, we feel it is important to note that at this point in time we have done nothing more than pressure testing, and some wet caving (more recently cave diving to 80m). We need to have a good think about what this testing actually means to customers, and we will look to develop a formal test protocol when a time window opens up. We are currently leaving on pressure test for 10 minutes as it seems like long enough to establish water tightness at depth, but would appreciate any feedback on this from anyone with knowledge of such testing. The Little Monkey team also need to get Nora 3 properly in the water over the coming months to confirm that it performs as we anticipate, and to evaluate switch operation at depth. We hope to start this shortly (November 2018).  

From an engineering perspective, there is an O ring at the Nora 3-dive front window, and an O ring between the 3-dive battery box and lid, both static obviously. There are no dynamic O rings as switch is a fully sealed piezo, with no moving parts through lamp housing. Battery box is of course opened and closed, and it would be prudent to keep O ring clean and replace if worn, as with any design of this nature. Battery box lid is bolted down on to the main box to affect consistent reliable closure for cave diving application. Cap head bolts are recessed and retained by O rings. The top of the battery box, on the back of the helmet is the last place any caver would want sticky up bits holding lid onto box! 

Nora 2xs battery boxes are individually pressure tested to 7 bar 60m. Nora 3-dive lamps supplied with 2xs battery boxes are by default only tested to 7 bar (though are constructed exactly the same as those tested to 14 bar and supplied with 3-dive box). We are not promoting the 2xs battery box as a solution for cave diving! The 2xs box of course offers the necessary robustness and water tightness to protect li-ion batteries from damage, but to maintain depth rating over time we would consider it necessary to regularly inspect and periodically adjust the catch plates in order to maintain optimal closure pressure of the clasps, and with the best will in the world people don't.

Important - Nora 3 cable glands are sealed into the lamp body and battery box, and should not be disassembled. 

The battery box O ring should be removed and cleaned (including O ring locating channel in battery box) before any dive, in order to ensure a good seal. Any leakage at this point, under pressure at depth, could propagate along cable and potentially cause damage to lamp unit. 

Should this occur, moisture may become visible under front window. In which case release front window screws and run lamp on a medium setting to remove moisture.  

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