Sovs reading slightly off on the sigma

[TommyTwoShots]

Hi all,

just a quick question to knowledgable folk;

I have a couple of 1895 half sovereigns. They both read just right of the sigma analyser brackets but inside at 90% gold. Is this normal? Has anyone seen this? 
 

Cheers

[Darr3nG]

28 minutes ago, TommyTwoShots said:

Hi all,

just a quick question to knowledgable folk;

I have a couple of 1895 half sovereigns. They both read just right of the sigma analyser brackets but inside at 90% gold. Is this normal? Has anyone seen this? 
 

Cheers

I've had this a few times with older half sovs.

The Sensor Specification Chart in the user guide isn't very helpful.

The most consistent reading I got while testing them, was by using the large wand - the coin fits perfectly - and holding the calibration disk on top.

 

[TommyTwoShots]

Just now, Darr3nG said:

I've had this a few times with older half sovs.

The Sensor Specification Chart in the user guide isn't very helpful.

The most consistent reading I got while testing them, was by using the large wand - the coin fits perfectly - and holding the calibration disk on top.

 

Many thanks. It’s happened a few times now, specifically with the older half sovs 

[LawrenceChard]

5 hours ago, TommyTwoShots said:

Hi all,

just a quick question to knowledgable folk;

I have a couple of 1895 half sovereigns. They both read just right of the sigma analyser brackets but inside at 90% gold. Is this normal? Has anyone seen this? 
 

Cheers

 

4 hours ago, Darr3nG said:

I've had this a few times with older half sovs.

The Sensor Specification Chart in the user guide isn't very helpful.

The most consistent reading I got while testing them, was by using the large wand - the coin fits perfectly - and holding the calibration disk on top.

 

Just this week, a customer returned a number of 999 silver bars to us.

She had informed us that they were giving an unusual reading on her Sigma testing machine.

We tested all the bars on our Niton XRF machine, which recorded perfect 999 readings on every bar, and we also tested each bar on both main sides, and in various places.

We were not surprised by any of this.

Before we acquired our XRF machine, we had discussion with Sheffield Assay Office, who also use XRF technology for some of their metal analysis work.

The most accurate method of analysing metal alloys remains the time-honoured fire or cupelation assay, but this is destuctive as it requires samples to be removed from the bars.

While all testing methods are subject to tolerance, and we have observed a small number of quirky results from our machine, it is almost certain that XRF analysis is more reliable than the methods used by Sigma machines.

At some stage in the future, we will obtain a Sigma, and do some of our own testing with it, but this will be mainly so that we can understand why they produce some false readings.

There are other topics / threads here on TSF which record unusual or unexpected results using Sigma machines, or similar technology.

 

[TommyTwoShots]

Many thanks! As always wise words.

[ady]

9 minutes ago, LawrenceChard said:

 

Just this week, a customer returned a number of 999 silver bars to us.

She had informed us that they were giving an unusual reading on her Sigma testing machine.

We tested all the bars on our Niton XRF machine, which recorded perfect 999 readings on every bar, and we also tested each bar on both main sides, and in various places.

We were not surprised by any of this.

Before we acquired our XRF machine, we had discussion with Sheffield Assay Office, who also use XRF technology for some of their metal analysis work.

The most accurate method of analysing metal alloys remains the time-honoured fire or cupelation assay, but this is destuctive as it requires samples to be removed from the bars.

While all testing methods are subject to tolerance, and we have observed a small number of quirky results from our machine, it is almost certain that XRF analysis is more reliable than the methods used by Sigma machines.

At some stage in the future, we will obtain a Sigma, and do some of our own testing with it, but this will be mainly so that we can understand why they produce some false readings.

There are other topics / threads here on TSF which record unusual or unexpected results using Sigma machines, or similar technology.

 

I have had dubious reading from the Sigma machine, but pleased with the overall results as appreciate the handling and experience of metals invaluable in the first place and only use my machine as another reassurance. I look forward to your valuation of the Sigma machine.

[James32]

21 minutes ago, LawrenceChard said:

 

Just this week, a customer returned a number of 999 silver bars to us.

She had informed us that they were giving an unusual reading on her Sigma testing machine.

We tested all the bars on our Niton XRF machine, which recorded perfect 999 readings on every bar, and we also tested each bar on both main sides, and in various places.

We were not surprised by any of this.

Before we acquired our XRF machine, we had discussion with Sheffield Assay Office, who also use XRF technology for some of their metal analysis work.

The most accurate method of analysing metal alloys remains the time-honoured fire or cupelation assay, but this is destuctive as it requires samples to be removed from the bars.

While all testing methods are subject to tolerance, and we have observed a small number of quirky results from our machine, it is almost certain that XRF analysis is more reliable than the methods used by Sigma machines.

At some stage in the future, we will obtain a Sigma, and do some of our own testing with it, but this will be mainly so that we can understand why they produce some false readings.

There are other topics / threads here on TSF which record unusual or unexpected results using Sigma machines, or similar technology.

 

What type of bars Lawrence?

[LawrenceChard]

Just now, James32 said:

What type of bars Lawrence?

There was a small selection of different brands. I only saw them very briefly, but they all appeared to be kilo bars.

[James32]

2 minutes ago, LawrenceChard said:

There was a small selection of different brands. I only saw them very briefly, but they all appeared to be kilo bars.

I'm shocked they where kilos,anything with a big/flat profile read well. what I have found is that if the bar has a raised edge or detail then it's can be irregular. 

If the bar/coin is too thin then it won't read without use of the wand. American eagles produce funky readings due to the dome shape and raised detail. 

 

 

[Rains]

Just now, James32 said:

I'm shocked they where kilos,anything with a big/flat profile read well. what I have found is that if the bar has a raised edge or detail then it's can be irregular. 

If the bar/coin is too thin then it won't read without use of the wand. American eagles produce funky readings due to the dome shape and raised detail. 

 

 

What wait bars does the machine do up to silver and gold wise?

[James32]

18 minutes ago, Rains said:

What wait bars does the machine do up to silver and gold wise?

Kilo is as big as you need on both then you can open a bank 😊

[Rains]

1 minute ago, James32 said:

Kilo is as big as you need on both then you can open a bank 😊

I was thinking 10oz max that is alot better

[LawrenceChard]

1 hour ago, Rains said:

What wait bars does the machine do up to silver and gold wise?

If you mean weight rather than wait, as big as will fit inside to protective hood.

One kilo silver bars fit very easily, but we have done larger bars and coins.

I am sure that 1,000 ounce silver bars would be too big, but I can't remember trying.

Niton do also make a hand-held machine for use on larger items, like steelwork or pipes in refineries.

You can probably find dimensions on the Niton UK site.

 

Edited March 10, 2022 by LawrenceChard

[Rains]

9 minutes ago, LawrenceChard said:

If you mean weight rather than wait, as big as will fit inside to protective hood.

One kilo silver bars fit very easily, but we have done larger bars and coins.

I am sure that 1,000 ounce silver bars would be too big, but I can't remember trying.

Niton do also make a hand-held machine for use on larger items, like steelwork or pipes in refineries.

You can probbly find dimensions on the Niton UK site.

 

Yes my 🧠  is not working properly tonight thanks 

[HerefordBullyun]

6 minutes ago, Rains said:

Yes my 🧠  is not working properly tonight thanks 

Too busy staring at your monkeys you bought dazzled ya brain

[LawrenceChard]

11 minutes ago, Rains said:

Yes my 🧠  is not working properly tonight thanks 

Q.E.D.

(Quite Easily Done)

🙂

[Roy]

8 minutes ago, LawrenceChard said:

Q.E.D.

(Quite Easily Done)

🙂

 

31 minutes ago, LawrenceChard said:

probbly

 

[Stu]

43 minutes ago, Roy said:

 

 

Prolly a mistook!

[SilverStorm]

On 10/03/2022 at 07:03, TommyTwoShots said:

Hi all,

just a quick question to knowledgable folk;

I have a couple of 1895 half sovereigns. They both read just right of the sigma analyser brackets but inside at 90% gold. Is this normal? Has anyone seen this? 
 

Cheers

What Sigma machine did you use to test your sovereigns?   

Correct me if I'm wrong, but 1895 half sovereign is composed of 0.9167 gold purity.   I got the info from the link below.

Link: Half Sovereign 1895, Coin from United Kingdom - Online Coin Club

If you are testing the half sovereigns using "pure" gold function, then of course the reading will be outside the brackets.  Because the half sovereign is not pure gold.   Pure gold function on the Sigma tests for 999 or 9999 fine gold, which the half sovereign is not.   

If the reading for 90% gold is inside the brackets, then that means your half sovereigns are reading correctly.  

[SilverStorm]

On 10/03/2022 at 12:29, LawrenceChard said:

 

Just this week, a customer returned a number of 999 silver bars to us.

She had informed us that they were giving an unusual reading on her Sigma testing machine.

We tested all the bars on our Niton XRF machine, which recorded perfect 999 readings on every bar, and we also tested each bar on both main sides, and in various places.

We were not surprised by any of this.

Before we acquired our XRF machine, we had discussion with Sheffield Assay Office, who also use XRF technology for some of their metal analysis work.

The most accurate method of analysing metal alloys remains the time-honoured fire or cupelation assay, but this is destuctive as it requires samples to be removed from the bars.

While all testing methods are subject to tolerance, and we have observed a small number of quirky results from our machine, it is almost certain that XRF analysis is more reliable than the methods used by Sigma machines.

At some stage in the future, we will obtain a Sigma, and do some of our own testing with it, but this will be mainly so that we can understand why they produce some false readings.

There are other topics / threads here on TSF which record unusual or unexpected results using Sigma machines, or similar technology.

 

No one testing method can be relied upon 100%.  I believe you agree with me on this point.  Even the Niton XRF gun has its limitations.  This is why everyone should use various testing methodologies to confirm the accuracy of their PM.  Unfortunately, it costs a lot of money get testing equipment, which may be out of reach for most people.

Edited March 13, 2022 by SilverStorm

[Rains]

6 hours ago, SilverStorm said:

No one testing method can be relied upon 100%.  I believe you agree with me on this point.  Even the Niton XRF gun has its limitations.  This is why everyone should use various testing methodologies to confirm the accuracy of their PM.  Unfortunately, it costs a lot of money get testing equipment, which may be out of reach for most people.

In the movies they just bite the coins 😄

[LawrenceChard]

7 hours ago, SilverStorm said:

No one testing method can be relied upon 100%.  I believe you agree with me on this point.  Even the Niton XRF gun has its limitations.  This is why everyone should use various testing methodologies to confirm the accuracy of their PM.  Unfortunately, it costs a lot of money get testing equipment, which may be out of reach for most people.

I agree with you about 99%.

You may have already seen this:

https://www.chards.co.uk/blog/krugerrand-gold-content/507

And I seem to remember posting about it on TSF.

Cupelation worked just fine, but can be ever so slightly destructive!

Assay Offices do use multiple methods, for different reasons, which reinforces your point.

It is probably more important though, for users to have some understanding of how their equipment works, and what its limitations are.

I have also noticed that there is a growing level of suspicion bordering on paranoia, probably because there are now so many YouTube videos, and threads on TSF and elsewhere about fakes, that people who get an unexpected reading from their testing device, that they immediately believe they have a fake, rather than think that it may be a quirky result from their favourite, and probably newly acquired, testing equipment.

At the other end of the spectrum, we hear of dorks who buy "silver" bars or coins via ebay, for less than intrinsic silver value, and fail to engage whatever vestigial brain matter they have. We have also encountered people who have bought "Krugerrands" from pawn shops for about £5 each, in the hope that the pawn shop has made a mistake in labelling them as imitation or gold plated.

Most people have eyes and brains, acquired free of charge at birth, but like any other testing equipment, no good if you forget to use it!

😎

[LawrenceChard]

On 10/03/2022 at 20:29, LawrenceChard said:

 

Just this week, a customer returned a number of 999 silver bars to us.

She had informed us that they were giving an unusual reading on her Sigma testing machine.

We tested all the bars on our Niton XRF machine, which recorded perfect 999 readings on every bar, and we also tested each bar on both main sides, and in various places.

We were not surprised by any of this.

Before we acquired our XRF machine, we had discussion with Sheffield Assay Office, who also use XRF technology for some of their metal analysis work.

The most accurate method of analysing metal alloys remains the time-honoured fire or cupelation assay, but this is destuctive as it requires samples to be removed from the bars.

While all testing methods are subject to tolerance, and we have observed a small number of quirky results from our machine, it is almost certain that XRF analysis is more reliable than the methods used by Sigma machines.

At some stage in the future, we will obtain a Sigma, and do some of our own testing with it, but this will be mainly so that we can understand why they produce some false readings.

There are other topics / threads here on TSF which record unusual or unexpected results using Sigma machines, or similar technology.

 

 

On 10/03/2022 at 20:47, ady said:

I have had dubious reading from the Sigma machine, but pleased with the overall results as appreciate the handling and experience of metals invaluable in the first place and only use my machine as another reassurance. I look forward to your valuation of the Sigma machine.

 

On 10/03/2022 at 20:51, James32 said:

What type of bars Lawrence?

 

On 10/03/2022 at 20:53, LawrenceChard said:

There was a small selection of different brands. I only saw them very briefly, but they all appeared to be kilo bars.

Follow Up:

I was at our office today, and Rochelle asked me not to talk while she was doing a short video of her Niton testing the silver bars. Actually, they all seemed to be Umicore, a well known reliable and respected brand, and were cast ones. I didn't check the size or weight, but it is not really important or relevant.

The reason for the video is that our customer still seems sceptical, and wanted to see us videoing the test before she would believe us.

These things happen!

So being the friendly helpful professional we are, we were doing exactly that.

Naturally, the test I watched said 999.

I pointed out the "details" button, which gives a reading to 4 figures instead of 3, and also lists more metals. It showed 9999, (four nines) which was a very satisfying result.

I noticed that all the bars, except for the one we were testing, were still in a plastic shrink pack, presumably its original packaging by Umicore.

Rochelle had also tested one through the plastic, because we are thorough, and we got a slightly different result, as might be expected.

I must check, but I suspect that all of the bars may have still been in their plastic shrink wrap when we received them back from the customer, which would of course have meant that she (the customer) was testing them through the plastic.

I am not totally astounded by this, as I have been around for a long time, and one thing I have learnt is that we are all different.

I strongly suspect she has not read the instructions.

I have suggested that we point our customer to this and other TSF threads about quirky Sigma results.

I also decided it was time we contacted Sigma, so I e-mailed them to invite them to send us an information pack, and samples for evaluation.

😎

 

[James32]

1 minute ago, LawrenceChard said:

 

 

 

Follow Up:

I was at our office today, and Rochelle asked me not to talk while she was doing a short video of her Niton testing the silver bars. Actually, they all seemed to be Umicore, a well known reliable and respected brand, and were cast ones. I didn't check the size or weight, but it is not really important or relevant.

The reason for the video is that our customer still seems sceptical, and wanted to see us videoing the test before she would believe us.

These things happen!

So being the friendly helpful professional we are, we were doing exactly that.

Naturally, the test I watched said 999.

I pointed out the "details" button, which gives a reading to 4 figures instead of 3, and also lists more metals. It showed 9999, (four nines) which was a very satisfying result.

I noticed that all the bars, except for the one we were testing, were still in a plastic shrink pack, presumably its original packaging by Umicore.

Rochelle had also tested one through the plastic, because we are thorough, and we got a slightly different result, as might be expected.

I must check, but I suspect that all of the bars may have still been in their plastic shrink wrap when we received them back from the customer, which would of course have meant that she (the customer) was testing them through the plastic.

I am not totally astounded by this, as I have been around for a long time, and one thing I have learnt is that we are all different.

I strongly suspect she has not read the instructions.

I have suggested that we point our customer to this and other TSF threads about quirky Sigma results.

I also decided it was time we contacted Sigma, so I e-mailed them to invite them to send us an information pack, and samples for evaluation.

😎

 

He/she probably still had the plastic on the sigma machine too ffs😅

[LawrenceChard]

6 minutes ago, James32 said:

He/she probably still had the plastic on the sigma machine too ffs😅

Brilliant! I never thought about that.

I think you just won another "comment of the day".

😎