Magnetometer Project

I LOVE finding out about different ways to appreciate the Sun and light in general. Use this forum to post your info or questions about various outside the mainstream ways to appreciate our life giving star!
User avatar
marktownley
Librarian
Librarian
Posts: 24534
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: Magnetometer Project

Post by marktownley » Fri Jan 16, 2015 6:38 am

That is good!
Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!

User avatar
grimble_cornet
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 3496
Joined: Tue Jul 10, 2012 5:10 pm
Location: UK West Midlands

Re: Magnetometer Project

Post by grimble_cornet » Fri Jan 16, 2015 2:59 pm

Thanks Stuart - that looks like good news :seesaw

I know that you are otherwise occupied for the next couple of days but........ I have a few other experiments to carry out so I'll continue with the commentary and you can catch up later.

So........ on to Phase 5:

While Stuart was playing with my data I decided to try to improve my thermal stability (or at least that of the Bat 5) :lol:

First stage was to build a 1" (2.5cm) 'box' out of medium density grey foam (packing from a TV). By cutting and sticking, I managed to encapsulate the Bat detector and Ultrasound transmitter within a 'fitted foam shell'.
This package was then wrapped in several layers of bubble wrap which was then placed in a 12x18x18" (30x45x45cm) plastic cool box.
The cool box was then placed in a room with the central heating radiator switched off - should reduce sudden temperature changes when central heating switches on/off?

I left this new arrangement running overnight:
15-16th January Magnetometer Data.jpg
15-16th January Magnetometer Data.jpg (179.28 KiB) Viewed 1830 times
Once again, good news that there is good agreement between my data and the Intermagnet data in terms of up/down 'events' BUT...... once again it shoots upwards at 0800!

OK..... either it is a temperature change at the Bat 5 OR it is a temperature change at the buried sensor OR it is something else happening :evil: :evil:

Here is my latest toy:
usb temperature logger.jpg
usb temperature logger.jpg (78.88 KiB) Viewed 1830 times
This sits in a usb port and records the temperature at the usb port and the temperature of the sensor attached by a lead.
I have now placed the sensor inside the bubble wrap next to the Bat 5 and the temperature is being recorded every 30 seconds - at the same interval used to record the magnetic field. Once this has run for 24 hours, I should be able to combine the two sets of data in Excel and, possible, use the temperature data to 'modify' the magnetic data :?: :?: :?: :?: :?:

Watch this space..................
.

.



.


Mike Garbett

Selection of Solar and Deep Sky images on Flickr: https://www.flickr.com/photos/mikegarbett/

User avatar
marktownley
Librarian
Librarian
Posts: 24534
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: Magnetometer Project

Post by marktownley » Sat Jan 17, 2015 12:26 am

I admire your dedication Sir, this is interesting to follow :bow2
Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!

Wah
Im an EXPERT!
Im an EXPERT!
Posts: 339
Joined: Tue May 01, 2012 2:14 am

Re: Magnetometer Project

Post by Wah » Sat Jan 17, 2015 12:41 am

:band2
I'm waiting for your better results!

User avatar
Carbon60
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 5491
Joined: Wed Mar 07, 2012 12:33 pm
Location: Lancashire, UK

Re: Magnetometer Project

Post by Carbon60 » Sat Jan 17, 2015 7:52 am

Mike,

As a point of reference, here are my temperature data measured at the Magenta 5. As you can see, temperature variation through the 24hr period (Jan 16th) is to within 0.3 Deg C, although over a longer period of several weeks, with changing weather conditions/ambient temperatures, it can vary to within about 1.5 degrees C.

The thermostat seems to control to within +/- 0.6 degrees, but again this depends on the ambient conditions. I always see a temperature differential between the set temp and the measured temp at the bat detector.
Temperature variation.jpg
Temperature variation.jpg (36.54 KiB) Viewed 1803 times
Stu.
Lunt LS60THa B1200 PTFT
150mm H-alpha Solar telescope with Lunt35 mod
DMK41, Basler acA1920-155
NEQ6 Pro-mount
Fluxgate Magnetometers (1s and 150s Cadence)
More images at http://www.flickr.com/photos/solarcarbon60/

User avatar
swisswalter
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 17951
Joined: Thu Feb 06, 2014 4:28 am
Location: Switzerland
Contact:

Re: Magnetometer Project

Post by swisswalter » Sat Jan 17, 2015 11:03 am

Hi Mike

another fine part of the story
Only stardust in the wind, some fine and some less fine scopes, filters and adapters as well. Switzerland 47 N, 9 E, in the heart of EUROPE :)

from 7 am - 7 pm http://www.nanosys.ch

from 7.01 pm - 6.59 am http://www.wastronomiko.com some times vice versa ;)

User avatar
grimble_cornet
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 3496
Joined: Tue Jul 10, 2012 5:10 pm
Location: UK West Midlands

Re: Magnetometer Project

Post by grimble_cornet » Sat Jan 17, 2015 11:50 am

That's very interesting Stuart.
I have been monitoring my cool box temperature over night using my new toy and there was not a vast amount of change BUT...... judging by the results, it takes very little to throw off the output from the Bat 5.

It was also helpful that a rather nice 'event' happened at about 0300 ut which my magnetometer picked up beautifully.
Here is a graphic showing my data, the matching Intermagnet data and my temperature log:
Effect of Temperature.jpg
I am very happy with the shape of my plot during 'the event' - I seem to be capturing the fluctuations very accurately although I need to 'tweak' the scaling slightly.
It all starts to go pear-shaped at about 0800. Even in a room with the radiator switched off (and inside an insulated box etc.) the temperature starts to climb once my central heating kicks in. The temperature only increases by about 1.5 degrees C but this is clearly enough to cause serious problems as my plot climbs away rapidly - as I have seen it do before.

I can see now why Stuart needs the vacuum flask inside a thermostatically controlled heat box :cry: :evil: :cry:

I don't really want to take my Bat 5 apart and can't find a vacuum flask big enough to take it otherwise so....................

As an alternative approach I might try to build in a correction factor for temperature using the data from my temperature logger.
Chances of finding a nice, simple, linear relationship are not good but................. here is the result of applying a 'first guess' correction:
First significant event temperature corrected.jpg
First significant event temperature corrected.jpg (182.48 KiB) Viewed 1795 times
Not perfect, and I'm not sure it will hold up under larger temperature swings but....... a promising first attempt?

I wonder if moving everything out to my observatory will make things easier........ at least the central heating won't be a problem :oops:


Another cliffhanger for Walter.........................
.

.



.


Mike Garbett

Selection of Solar and Deep Sky images on Flickr: https://www.flickr.com/photos/mikegarbett/

User avatar
marktownley
Librarian
Librarian
Posts: 24534
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: Magnetometer Project

Post by marktownley » Sat Jan 17, 2015 12:00 pm

Yes, will be interesting see how the correction factor ties in with data longer term.
Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!

User avatar
grimble_cornet
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 3496
Joined: Tue Jul 10, 2012 5:10 pm
Location: UK West Midlands

Re: Magnetometer Project

Post by grimble_cornet » Sat Jan 17, 2015 8:32 pm

Mmmmmmm................. having spent most of the day playing with numbers - it doesn't look good :cry: :evil: :cry:

The thermal response of the Bat 5 is both severe and non-linear :roll:
I can build in correction factors which work very well over a few degrees but that will be of little/no use when the temperature is changing by 10 degrees or more during the day and won't be able to cope with a range of 0-25 degrees over the year :(
Even with the Bat 5 inside an insulated package within an insulated cool-box......... the temperature drift has major consequences :cry:

The graphic below says it all really:

On the left, we see that my magnetometer can match almost perfectly the data collected by professional stations - as long as the temperature remains stable to within about 1 degree C. The 'jagged' appearance of my data is a result of me taking readings more frequently (30 seconds) - it will become 'smoother' (for better or worse?) once I change over to the 150s interval used by Stuart.

However, once the temperature of the Bat 5 Detector is allowed to change by just a few degrees........ the whole thing falls apart with the accurate data being swamped by the 'thermal noise'.
Temperature Sensitivity.jpg
If I try to compensate for more than a few degrees, it becomes quite complex and the corrections screw up the calculations used to extract field strength from the frequency. I guess that a better mathematician (Stuart?) could sort something out but it looks as if my long-term solution will be the same as Stuart's which is a thermostatically controlled box.
.

.



.


Mike Garbett

Selection of Solar and Deep Sky images on Flickr: https://www.flickr.com/photos/mikegarbett/

User avatar
marktownley
Librarian
Librarian
Posts: 24534
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: Magnetometer Project

Post by marktownley » Sat Jan 17, 2015 10:19 pm

How do the 'professionals' keep their equipment thermally stable?
Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!

Wah
Im an EXPERT!
Im an EXPERT!
Posts: 339
Joined: Tue May 01, 2012 2:14 am

Re: Magnetometer Project

Post by Wah » Sun Jan 18, 2015 6:02 am

How about using a daystar temperature control system? Hehehe…

User avatar
swisswalter
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 17951
Joined: Thu Feb 06, 2014 4:28 am
Location: Switzerland
Contact:

Re: Magnetometer Project

Post by swisswalter » Sun Jan 18, 2015 1:47 pm

Hi Mike

very interesting results. and congratulations on the good match. Have thought about putting the whole Bat setup in a fridge :idea:
Only stardust in the wind, some fine and some less fine scopes, filters and adapters as well. Switzerland 47 N, 9 E, in the heart of EUROPE :)

from 7 am - 7 pm http://www.nanosys.ch

from 7.01 pm - 6.59 am http://www.wastronomiko.com some times vice versa ;)

User avatar
grimble_cornet
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 3496
Joined: Tue Jul 10, 2012 5:10 pm
Location: UK West Midlands

Re: Magnetometer Project

Post by grimble_cornet » Sun Jan 18, 2015 3:25 pm

DayStar temperature control system.......... nice low cost solution, maybe I could cannibalise the Quark? :lol: :roll: :lol:

Now, Walter........ a fridge is an interesting idea :idea:
I had already considered an Electrically Powered Coolbox but the cost is fast approaching that of Stuart's thermostatically controlled heating mat and I doubt if the temperature control would be good enough.
My experiments suggest that I need to be able to keep the temperature stable to within 1 degree C or better to get good results.
I tried putting the Bat 5 in my observatory over night just to see how well that would work (no central heating to worry about):
Overnight in the Observatory.jpg
Overnight in the Observatory.jpg (257.33 KiB) Viewed 1760 times
As you can see, a change of just 3 degrees is enough to totally distort/swamp the true signal.

Only between about 0600 and 1100 when the temperature is very stable, do we see the true magnetic data emerge :cry: :evil: :cry:


If I can re-route the cable........................ it just might be long enough to reach my milk/beer fridge so well worth a try. I will stick my temperature logger in that fridge and see how stable the temperature is.
.

.



.


Mike Garbett

Selection of Solar and Deep Sky images on Flickr: https://www.flickr.com/photos/mikegarbett/

User avatar
marktownley
Librarian
Librarian
Posts: 24534
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: Magnetometer Project

Post by marktownley » Sun Jan 18, 2015 6:18 pm

Now you're talking beer it will all sort itself out ;)
Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!

User avatar
Carbon60
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 5491
Joined: Wed Mar 07, 2012 12:33 pm
Location: Lancashire, UK

Re: Magnetometer Project

Post by Carbon60 » Sun Jan 18, 2015 9:26 pm

It's funny how we're thinking along the same lines. I considered temperature correction, which is why I bought the digital thermometer, but then realised that this can only be applied at the data analysis stage. At the time of data capture, the Spectrum Lab chart would be severely distorted by the temperature excursions throughout the day, making it impossible to properly view any true geomagnetic effects on the screen at the time the data were being recorded. I also thought of using a fridge, but I was concerned about possible condensation inside the Bat 5 and I'm not sure how tight the temperature control is on a cheap small fridge. It will be interesting to see what measurements you come back with, Mike.


Stu.
Lunt LS60THa B1200 PTFT
150mm H-alpha Solar telescope with Lunt35 mod
DMK41, Basler acA1920-155
NEQ6 Pro-mount
Fluxgate Magnetometers (1s and 150s Cadence)
More images at http://www.flickr.com/photos/solarcarbon60/

User avatar
grimble_cornet
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 3496
Joined: Tue Jul 10, 2012 5:10 pm
Location: UK West Midlands

Re: Magnetometer Project

Post by grimble_cornet » Sun Jan 18, 2015 9:54 pm

Good point about the condensation Stuart.
I have a pier on my patio with my HEQ5 Pro permanently installed. I place a cloth bag over the mount, a large polythene bag over/around that and a chimea cover over the whole lot................. and I still get condensation on the mount when the temperature drops below freezing as it did last night.
I have my temperature probe in my milk/beer fridge which lives in my un-heated laundry room - we will see how good the temperature control is when its close to freezing outside. Unless the temperature change is less than 1 degree C then I think I would be wasting my time - especially as I assume the fridge will struggle to maintain temperature in the Summer.
If I could see a solution to the 'getting the Bat 5 inside a vacuum flask without taking it apart' problem, I would just bite the bullet and get the heat mat / thermostat / cool-box that clearly works for you.
.

.



.


Mike Garbett

Selection of Solar and Deep Sky images on Flickr: https://www.flickr.com/photos/mikegarbett/

User avatar
swisswalter
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 17951
Joined: Thu Feb 06, 2014 4:28 am
Location: Switzerland
Contact:

Re: Magnetometer Project

Post by swisswalter » Mon Jan 19, 2015 5:00 am

Beer, beer, beer from the fridge :hamster: :hamster: :hamster:
Only stardust in the wind, some fine and some less fine scopes, filters and adapters as well. Switzerland 47 N, 9 E, in the heart of EUROPE :)

from 7 am - 7 pm http://www.nanosys.ch

from 7.01 pm - 6.59 am http://www.wastronomiko.com some times vice versa ;)

ham
The Sun?
The Sun?
Posts: 8
Joined: Thu Nov 20, 2014 11:20 pm
Location: Hong Kong SAR China

Re: Magnetometer Project

Post by ham » Mon Jan 19, 2015 7:03 am

Hi Stuart,

I am very interest to do this project,I live in tall concrete appartment building,about 25m metres height of my house, my windows is oriented north to north east open area,but I can't see the sun or moon all years long on my window view (blocked by another building).may I do this project too?,The sensor needs to be installed under hidden area? Can I make the shelter or waterproof box to install this sensor near the wall?

User avatar
grimble_cornet
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 3496
Joined: Tue Jul 10, 2012 5:10 pm
Location: UK West Midlands

Re: Magnetometer Project

Post by grimble_cornet » Mon Jan 19, 2015 2:56 pm

The temperature probe spent the night in the fridge with the beer:
The beer fridge.jpg
The beer fridge.jpg (138.73 KiB) Viewed 1712 times
I find it difficult to believe it is that good :o

After a bit of re-routing of wires and a lot of cursing.......... I have the Bat 5 set up in my beer fridge and the trace is dropping with the temperature.
We will see if it stabilises and stays that way for 24 hours :?: :roll: :?:
.

.



.


Mike Garbett

Selection of Solar and Deep Sky images on Flickr: https://www.flickr.com/photos/mikegarbett/

User avatar
swisswalter
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 17951
Joined: Thu Feb 06, 2014 4:28 am
Location: Switzerland
Contact:

Re: Magnetometer Project

Post by swisswalter » Mon Jan 19, 2015 8:19 pm

Hi Mike

Beers, beers, beers :hamster: :hamster: :hamster:

I don't think you have to go for deep temperatures, just set it to something around your average temperatures, so it can handle getting colder and warmer. Do you need my adress to send the beers to ;)
Only stardust in the wind, some fine and some less fine scopes, filters and adapters as well. Switzerland 47 N, 9 E, in the heart of EUROPE :)

from 7 am - 7 pm http://www.nanosys.ch

from 7.01 pm - 6.59 am http://www.wastronomiko.com some times vice versa ;)

User avatar
swisswalter
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 17951
Joined: Thu Feb 06, 2014 4:28 am
Location: Switzerland
Contact:

Re: Magnetometer Project

Post by swisswalter » Mon Jan 19, 2015 8:21 pm

ham wrote:Hi Stuart,

I am very interest to do this project,I live in tall concrete appartment building,about 25m metres height of my house, my windows is oriented north to north east open area,but I can't see the sun or moon all years long on my window view (blocked by another building).may I do this project too?,The sensor needs to be installed under hidden area? Can I make the shelter or waterproof box to install this sensor near the wall?
Hi Ham


I'm sure you can do that. Not sure about the wires in the near surrounding
Only stardust in the wind, some fine and some less fine scopes, filters and adapters as well. Switzerland 47 N, 9 E, in the heart of EUROPE :)

from 7 am - 7 pm http://www.nanosys.ch

from 7.01 pm - 6.59 am http://www.wastronomiko.com some times vice versa ;)

User avatar
Carbon60
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 5491
Joined: Wed Mar 07, 2012 12:33 pm
Location: Lancashire, UK

Re: Magnetometer Project

Post by Carbon60 » Mon Jan 19, 2015 10:24 pm

Wow....that looks to be very stable indeed, Mike. Nice one. It will be interesting to see the next dataset. If the temperature really is so stable you'll have no problem detecting every detail.

Ham, In contrast, regrettably, I think you'll have significant difficulties with magnetic interference in your environment. These things are really very sensitive and solar effects are usually very weak in comparison with everyday magnetic fields generated by wiring around the home.

Stu.
Lunt LS60THa B1200 PTFT
150mm H-alpha Solar telescope with Lunt35 mod
DMK41, Basler acA1920-155
NEQ6 Pro-mount
Fluxgate Magnetometers (1s and 150s Cadence)
More images at http://www.flickr.com/photos/solarcarbon60/

User avatar
grimble_cornet
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 3496
Joined: Tue Jul 10, 2012 5:10 pm
Location: UK West Midlands

Re: Magnetometer Project

Post by grimble_cornet » Tue Jan 20, 2015 11:37 am

Well, following Walter's inspired idea (or alcohol fixation) - 21 hours in the beer fridge and things are looking rather good.......
The temperature changed by about 0.5 degrees C overnight but the data plot looks pretty good when compared to the data from Intermagnet :P
The different Intermagnet stations all show slight variations so I will try to compare mine with a number of different ones at some point.
21 hours in the beer fridge.jpg

This data set seems to suggest that the buried magnetic sensor is working well: especially as we had -4C overnight so a 7 degree swing during the observation period.
It also suggests that if I can maintain the temperature of the Bat 5 to within 0.5 degrees C ............. I will have a pretty accurate and (to my simple mind anyway) impressive magnetometer :P
.

.



.


Mike Garbett

Selection of Solar and Deep Sky images on Flickr: https://www.flickr.com/photos/mikegarbett/

User avatar
marktownley
Librarian
Librarian
Posts: 24534
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: Magnetometer Project

Post by marktownley » Tue Jan 20, 2015 12:00 pm

The beer fridge saves the day!
Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!

User avatar
Carbon60
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 5491
Joined: Wed Mar 07, 2012 12:33 pm
Location: Lancashire, UK

Re: Magnetometer Project

Post by Carbon60 » Tue Jan 20, 2015 12:16 pm

Perfect, Mike.

The beer fridge looks like a great alternative to the thermostatically controlled 'cool box'. Let's hope it all holds out long-term. Of course, now it means that you can't open the fridge to get your beer out without risking corrupting your data, but sometimes sacrifices have to be made. :lol: :lol:

You might want to reduce the capture rate to smooth the curves a bit (2 minutes, or so, works well), or do what I do and capture one set at 1 second intervals and another at 2.5 minute intervals (you can run more than one 'Spectrum Lab' at any one time). This gives you the ability to really focus in on any interesting transitions, such as the point of impact when a CME passes by, but present smoother curves without too much data for a more general view.

Anyhow, it proves the point that the system can be set up by others and that it really works when temperature and voltage regulation measures are implemented. These, as you have seen, are really critical.

Cheers

Stu.
Lunt LS60THa B1200 PTFT
150mm H-alpha Solar telescope with Lunt35 mod
DMK41, Basler acA1920-155
NEQ6 Pro-mount
Fluxgate Magnetometers (1s and 150s Cadence)
More images at http://www.flickr.com/photos/solarcarbon60/

Post Reply

Who is online

Users browsing this forum: No registered users and 4 guests