Ivconic Magnetometer/Gradiometer

[ivconic]

At this stage it is the time to write some so so documentation.
Because things are getting more complicated in code... on the other side; i am not getting any younger in time (read as: getting more and more senile)...
So ...
no matter the fact that i am indeed "pioneer" in use of most of the MS tools; as time goes by: i am getting harder and harder "*itch-slap"-ed from the newer MS versions.
In order to do simple thing; i had to learn some basics from a start again. They (yoyos in MS) simply made total disorder in newer versions!
I guess it is because Gates went on holiday for undefined period. No boss in building = total democracy!


I try to hide behind such reasons and explain why my first attempt of writing manual is not prefect...
One man band show is sometimes pretty exhausting... i tell ya!
So here it is... don't spit!

[MTammet]

Cool!
After we exchanged emails; i was seriously buried into such problematic.
Your suggestions are making lot of sense to me.
Therefore i do seriously intend to deal with that in nearest possible future.
It is not the price the deciding factor. It is the gabarite and setup of such and similar modules.
I was rather thinking on designing my own lock-in amplifier.
Current version of code is having simpler running average filter.
Quite subject to improve in next updates.
What to say?
Big THANKS for pretty constructive suggestions!
Cheers!

I recommend to use the same chip.
Best Regards

[ivconic]

[MTammet]

Make it support .csv. Then it is even greater. I use freeware
http://www.sussexarch.org.uk/geophys/snuffler.html

Best Regards

[ivconic]

At first i did the code to generate csv. Nothing easier than that.
Later i decided to do my own file format. Encoded. To match only my software.
But i don't give up from csv too.
It is very easy to add several formats, code to generate them at the same time on SD card.
Will see.
There are too many more important things to finish yet.
This is growing project. More to come.

[MTammet]

At first i did the code to generate csv. Nothing easier than that.
Later i decided to do my own file format. Encoded. To match only my software.
But i don't give up from csv too.
It is very easy to add several formats, code to generate them at the same time on SD card.
Will see.


There are too many more important things to finish yet.
This is growing project. More to come.

Your software is ok for fast survey and it has 3D. I f you improve it a bit more you will have customers belive me. There are only few geoplotting softwares in the market and they cost fortune.

[ivconic]

Snuffler is great software, written by great enthusiast and expert.
But also very conversant and educated for that area of interest.
I can not compete with that. No way!
But adding .csv format is easy task.
Will do.

[ivconic]

Important changes and updates are made now:

[ivconic]

180 degree sensor pipe rotating mechanism with limiters:

[ivconic]

...

[ivconic]

Few weeks ago i coincidentally stumbled on splendid offer, decent batch of FMG-3H sensors.
Week ago i got 4 of them. Yesterday i made second order.
It takes approx 10 days to arrive here. With acceptable taxes.
Still didn't have time to perform more detailed tests and comparisons.
Too much responsibilities these days, cant take a breathe!
First thing on a list is to test and check those and compare their performing with previous FGM-3 and FG-3 models.
What exactly the "H" stands for? I tried to look up for Speake documentations, i am sure i had it on my disk... seems i was wrong.
And there is no Speake web page anymore on the net.
On skim look those appears to be the same as FGM-3. Physically.
Will see. Need to place them in a pipe and perform proper calibration procedure.
In case somebody interested, here is the link:

https://www.tutti.ch/de/vi/aargau/ga...389?redirected

[ivconic]

It's amazing that i completely overlooked a few details in the articles that are circulating on the net for so much time!
I read these articles many times before, but i always overlooked some details!
For example here are few short details:

"...Sensitivity ± 50,000 nT [± 15,000 nT for FGM-3h] at 5 V operating voltage..."

and this attracted my attention too:

"..The Feedback pin allows the use of an internal over-wound coil to compensate or null the ambient field. It also could be used to counteract temperature variation effects..."

Ok, first one is clear. But second one is something that will need clarification. The feedback pin.
Is there anybody that ever used that pin?
How it should look like; the circuitry that engages the feedback pin on a sensor?
Any ideas?

[Krzysztof]

In the network 10 years ago was an example of temperature measurement and regulator connected to PIN Feedback.
FGM-3 minimum varies with temperatur.
Cure:
1. measure the characteristics of f (dT).
2. Add to the current to the feedback pin compatible to [-f (d)].
In practice, changes to short term are minimal when the sensor is insulated thermally.
Already have a greater effect to changes derived from the activity of the Sun.
Then the best is gradiometer differential.
Chris.

PS.
In addition, the feedback pin moves the range [± 15.000 nT for FGM-3 h] linear B (H), because the work at axis "Z" (and there is a level of around 40, 000nT).
Only with caution because FGM-3 has a large coefficient of M (between coils) which generates additional boundary interference wave using e.g.: LM334.
As a result, in my designs sensors stopped the use of feedback to the thermal insulation.

[ivconic]

In the network 10 years ago was an example of temperature measurement and regulator connected to PIN Feedback.
FGM-3 minimum varies with temperatur.
Cure:
1. measure the characteristics of f (dT).
2. Add to the current to the feedback pin compatible to [-f (d)].
In practice, changes to short term are minimal when the sensor is insulated thermally.
Already have a greater effect to changes derived from the activity of the Sun.
Then the best is gradiometer differential.
Chris.

PS.
In addition, the feedback pin moves the range [± 15.000 nT for FGM-3 h] linear B (H), because the work at axis "Z" (and there is a level of around 40, 000nT).
Only with caution because FGM-3 has a large coefficient of M (between coils) which generates additional boundary interference wave using e.g.: LM334.
As a result, in my designs sensors stopped the use of feedback to the thermal insulation.

That's a good info, thanks!
Few details:
1) "...example of temperature measurement and regulator connected to PIN Feedback..."
By any chance; do you have the schematic of that part?
2) "...In practice, changes to short term are minimal when the sensor is insulated thermally..."
This is good point. My gradiometer is planned as "short term" instrument for short term matrix surveys.
I haven't insulated sensors in pipe at all though.
This may present an issue at some situations (afraid in most of the situations).
There are two solutions; to apply good insulation or/and to add the circuit you've mention it.
Applying an insulation is easy part. Insulation foam will do.
But also i would like to try with control over the feedback pin. I don't have any starting point though.
So far i haven't seen any practical example.

[Krzysztof]

Here measure the effect of temperature on FGM-3:
https://www.picotech.com/library/exp...magnetic-field
http://www.reeve.com/FGMSensors.htm
http://www.reeve.com/images/FGM%20Se...rSchematic.PDF
I'm looking for further.

My insulation is a sensor inside the hollow cylinder made of polyurethane.
All the ends of the tube diameter of 50 mm length 1 m from the Central tube of the vacuum cleaner (tested best stiffness in one axis).