DistoXtra Safe

[footleg]

I have now got my DistoX installed in an Aquapak 'small whanganui' bag. It works fine in the bag (at least above ground) and should now be waterproof down to -5m. Simply put it in the bag and away you go. No modifications needed. I wrapped a couple of rubber bands around the case to keep the clear part of the case held over the front window. The case appears to have no effect on the distance measurements. I'll be testing it underground in the next couple of weeks and will report back on how it performs when the case gets wet or muddy.

 

[SamT]

Sounds good 

Let us know how you get on.

 

[footleg]

OK, results from initial underground testing. The DistoX was perfectly usable in the case but with a reduced maximum distance it could measure. Somewhere around 20m the Disto can no longer get a reading. We noticed that the case very slightly diffuses the beam. So if you are wanting to measure huge passages quickly then you would want to take it out of the case. But in most caves a detailed survey should be done in legs shorter than 20m anyway or it is difficult to sketch passage details accurately. (Shorter legs also give a more accurate centreline. I think some research found that the optimal leg length was 7m to minimise the errors in a survey.)

The case did not get muddy, so we did not get to see how it performed with muck on the case too. But it did protect the DistoX from any danger of getting wet. So is ideal for very wet passages.

 

[wookey]

That '7m' comes from the point when the angular errors of compass/clino start to become more than the tape error. It has little relevance to distoX surveying.

It's quite true that you really want legs under 30m to have a hope of sketching properly (unless you have exceptionally boring passage I've been sketcher when team Mulu have been given a posh disto and f*cking enormous passage and are about 1/4 mile away shouting '73.2', '64.7', '71.6', 'come, on get a move on'. Not ideal.