Cavechat.org

I calibrated and tested the X2 with the NL firmware and the NL version of Pocket Topo yesterday. It calibrated with in impressive delta of 0.10 with NL enabled (0.45 without).

The compass test course results were good and the X2 was not subject to the odd left / right orientation error that has always affected the A3 Disto Xs on our surface compass test course. I calibrated 4 A3 Disto Xs at the same time and they all exhibited this orientation error (outdoors only), but the X2 did not. Yay!

The data spread was 0.4 on the foresights and 0.7 on the backsights across all orientations outdoors. In the cave test course it was 0.5 and 0.5.

Brian Pease also reported good results with the NL software. If you are seeing large delta on the level calibration shots, it is the result of non-linearity in the accelerometers and you should get the NL firmware and PocketTopo version from Beat Heeb. Not all X2s are affected by this. Look at the calibration file (you did save them, didn't you) to see if your X2 is affected.

Should have a second X2 ready for calibration tonight.

That's good news! My DistoX2 doesn't seem to have the accelerometer non-linearity problem, but I might try the new calibration algorithm anyway.

On a slightly separate topic ... there was some speculation that due to the internally mounted, non-magnetic Li-Po battery, calibrations might not be needed very often, or possibly not at all. However, I'm finding that the FS/BS agreement and spread of measurements at different orientations does get worse in time. The clino measurements don't seem to move, but the magnetometer does seem to drive the need for recalibration. I'm finding this to be necessary at least once a month. Fortunately, with practice I'm finding that calibration in a cave only takes about 5 minutes. I'm giving up on trying to calibrate on the surface. There are too many hidden sources of interference. The other thing I've found is that I get better (i.e. lower) delta values when I shoot a fixed target for measurements 17-56 (vertices of the cube + up and down), and being in a cave provides many 3D targets that aren't always available outdoors.

Derek,

I have the Theodolite comparison data with a May cal, pre-NL firmware, the Friday just after calibration comparison, and a Sunday, post cave trip and more importantly post-battery recharge. On the the second X2, I have the theodolite comparison immediately after the first calibration on Sunday. I will post the graphs when I get a chance.

If you saved any of your calibration files from PocketTopo, you can open them in the NL version of PocketTopo and turn the NL feature on. If it changes your calibration overall delta it will be worth installing the firmware update and using the NL version to calibrate in the future.

I suppose Luc will be adding the NL feature to the Palm Auriga Disto X calibration software in the future.

LWB wrote:I suppose Luc will be adding the NL feature to the Palm Auriga Disto X calibration software in the future.

I wrote Beat to learn about the details.

May I mention the PalmOS calibration program I publish is absolutely independent from Auriga (it's a separate standalone program), unlike on (all?) other platforms. I feel you shouldn't have to adopt/learn a given cave survey software just to use a measurement instrument.

The Disto X calibration routine Luc wrote for the Palm is very user friendly. And the Bluetooth connection under the Palm OS is less troublesome than under Windows Mobile. Luc did a nice job.

The only reason to use PocketTopo to calibrate is to be able to save and to export (as text) the calibration data. The text export also provides the calibration matrix that is uploaded to the Disto X. It can be helpful in diagnosing a problem, but is not for the average user. Beat was collecting calibration files to sort out what was going on with some of the X2s that had high deltas on the level shots. That was what led to the new "NL" firmware and new version of PocketTopo to correct the non-linearity in some accelerometers.

Here is the difference for one Disto X2 compared to Theodolite data of the same course, results before and after the NL firmware. Data taken immediately after calibration.

LWB wrote:The Disto X calibration routine Luc wrote for the Palm is very user friendly. And the Bluetooth connection under the Palm OS is less troublesome than under Windows Mobile. Luc did a nice job.

The only reason to use PocketTopo to calibrate is to be able to save and to export (as text) the calibration data. The text export also provides the calibration matrix that is uploaded to the Disto X. It can be helpful in diagnosing a problem, but is not for the average user. Beat was collecting calibration files to sort out what was going on with some of the X2s that had high deltas on the level shots. That was what led to the new "NL" firmware and new version of PocketTopo to correct the non-linearity in some accelerometers.

About two years ago, as per your own request, I implemented a new window that lets you view and edit (remove) raw measures based on their individual calibration result. This data can be saved as a digital file in Beat's format if you need to send him the data for diagnosis. It can also be reloaded in the program for further viewing pleasure.

Time to download the new version ;)

Luc,

I have used the version that allows viewing of the data and removing a bad point if desired. Those were much appreciated changes. I don't recall a way to save it, but I haven't looked recently and I haven't checked to see if there is a more recent version. It seemed to me that it lacked the text export feature that put the calibration matrix at the bottom of the data, it only saves a .cal file. I will have to go back and look. Can the .cal file it creates be loaded into pocket topo? That way the calibration matrix could be saved via the text export.

I don't see how to open an existing .cal file on the Palm. The version says 2.02, July 27, 2012

Since I started playing with the X2, I have been using PocketTopo to calibrate. Now I will likely wait until you implement the NL algorithms before going back to the Palm. It's easier to use the same PDA to calibrate the A3 Disto Xs and the new Disto X2s.

The NL version of firmware is not full tested till now. So it is better to wait to be officially available.

Micro User-Guide for DistoX2 - print it, fold it, insert into battery compartment:



http://http://cachtice.speleo.sk/pub/distoX2_large_border.pdf

Good idea Martin. I made a similar key printed on a business card. I was going to laminate it and put in it the Pelican 1015 case with the Disto X2. Never thought of sticking it inside the battery compartment. By the way the Pelican 1015 is a perfect fit for the X2.

Martin - I noticed in your picture that you did not remove the "endpiece" on the Disto per step 7 of the assembly manual:

http://paperless.bheeb.ch/download/Dist ... Manual.pdf

I just checked an unmodified Disto X310 and the right side (when looking at the device battery cover) of the endpiece does appear to have a small magnet in it. I'm in the process of building 3 DixtoX2 units and would prefer to leave this endpiece in place to keep the case waterproof. Were you somehow able to remove this magnet, or have you found that leaving it in does not impact the measurements? Thanks in advance!

It is possible to remove the magnet without destroying the bracket (or so I've heard). Martin can probably tell us how. But the springs that operate the bracket are magnetic you want to remove them. And so are the 6 screws that hold the case together. I replaced all of those with brass. Small metric screws are not easily found (and brass is even harder) - but McMaster-Carr has them.

I don't remember if the E7400X has washers in it, but all the washers in the A3 are magnetic, so check them if there are some. The A3 Disto X calibrations improved when all washer and all screws were replaced with brass.

You can fill the tiny holes left by the bracket pins with silicon or another sealer to keep the case waterproof.

I'm looking forward to testing two Disto X2s to see how much the calibration has changed after 1 month.

LWB wrote:It is possible to remove the magnet without destroying the bracket (or so I've heard). Martin can probably tell us how. But the springs that operate the bracket are magnetic you want to remove them. And so are the 6 screws that hold the case together. I replaced all of those with brass. Small metric screws are not easily found (and brass is even harder) - but McMaster-Carr has them.

Use sharp cutter, or small soldering tool, or booth. :)

I don't remember if the E7400X has washers in it, but all the washers in the A3 are magnetic, so check them if there are some. The A3 Disto X calibrations improved when all washer and all screws were replaced with brass.

Washers are from plastic.

Japanese Screws

Heads and All Threads


Kettles Wood Drive,

Woodgate Business Park,

Birmingham,

United Kingdom 
B32 3DB

t: +44 121 506 6300

e: sales@japanesescrews.com
http://www.japanesescrews.com

LWB wrote:Small metric screws are not easily found (and brass is even harder) - but McMaster-Carr has them.

Can you tell me the McMaster part number? Thanks!