DIY Densimeter (Cek Ketulinan Silver Sendiri)

7/30/2019 DIY Densimeter (Cek Ketulinan Silver Sendiri)

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CHEAPEST DIY way to test how genuine your silver is.

By: Alan Teoh (2012)

If you have any questions, please do not hesitate to contact me via email [email protected] or add me

in Facebook.

Precious metals counterfeiting is currently common among silver coins and bars as the price of silver

become more expensive. People think that silver weight test is sufficient to test whether their silver is

genuine or otherwise but unfortunately that is not true.

A few non destructive and yet effective methods to measure the silver purity for your silver coins and

bars are Dimension (diameter + thickness) & Weight Test and Specific Gravity Test by using a

Densimeter.

Dimension (diameter + thickness) & Weight Test

Reliability Level: VERY GOOD (This test will rule out most fakes, however, some similar cheaper metals

such as Molybdenum, with a specific metal density of (10.22) are so close to Silver (10.49) that only a

Specific Density test can rule this out). A digital caliper is recommended for this test.

Each government minted silver coin has specific mint-issued dimensions and weight or specifications

which counterfeits can hardly match. Silver, being a unique element, possesses specific elemental

density differing from other metals. This means that if someone were to make a counterfeit coin out of

different metals and try to make the same weight and diameter as an original then it would turn out to

be a different thickness, or if has the same thickness it would be of a different diameter. This scientific

phenomenon occurs because since other metals expand differently, they do not create the same exact

thickness, diameter and weight as silver. If the diameter, thickness, weight and shape match the Mint

Specs, your coin is likely authentic. (Note: Some older circulated silver coins may be minutely thinner

and lighter as they are worn and lost some metal. Also as Silver becomes more expensive, Silver-Plated

Molybdenum coins may become a risk; although this is probably more likely with bars.)

Specific Gravity test

Reliability Level: VERY GOOD / EXCELLENT (This test is most effective when combined with test above.

Specific Density test will yield an extremely accurate measurement of silvers unique elemental density:

10.49).

Specific Gravity test can be done at home using a Densimeter. If money is no object, buy a Specific

Gravity Kit and accurate Scale which measures specific gravity to the hundredth of a gram (0.01g), or

consider an accuracy of 0.001g. However, the higher the accuracy of the scale, the more costly it is.

These tools can be easily found on eBay. However, for a simpler version, you can actually DIY.


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Materials

(A): 4 pieces of acrylic plastic glued

together to form a frame. It is

recommended to use acrylic plastic for

a more durable and stronger frame.

The frame measurement is 8 X 8 X 5.

Two additional plastic beams were

glued at the top right and left corners

of the frame to make the frame

stronger.

(B): 4 pieces of large size cable-tie is

used to hold the aluminium plate. Drill

4 rectangular holes on the plastic and

put down the cable-tie through the

holes that you just drilled. The large

size cable-tie is tied to the side of the plate to hang the aluminium plate from above. (Important note:

Be careful when drilling the hole. Find a solid platform to support the plastic when drilling the hole.

Otherwise, you might accidentally damage or crack and spoil the plastic)

(C): Small tupperware is used as container. This container is commonly found in your kitchen or can be

easily bought from the store. Do make sure that the base of the container is flat so that it can stably sit

on the scale. Light weight container is recommended for small electronic scale. The container size is 3.5X 3.5 X 1.5.

(D): A square aluminium plate is die-cut to a dimension that fits into the container but the plate should

not touch any part of the container. Aluminium plate was used because aluminium is a softer metal

compared to silver. This is to create scratch resistance for the silver in case of harsh contact between the

two metals. The measurement is 2.2 X 2.2 X 0.05.

(E) An electronic scale is used for this test. If money is no object, buy an accurate scale which measures

to the hundredth of a gram (0.01g), or consider an accuracy of 0.001g. The higher the accuracy of the

scale, the higher the cost.

If you have trouble locating the materials, you may email or message me and I will try to help.


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How does a Densimeter operate?

Densimeters operate by weighing the water being displaced by the silver when the silver enters the

water and is placed on the plate that was hung from above without touching any part of the container.

Water is poured into the container until it covers the aluminium plate by approximately 1cm. Ensure

that minimal bubbles are trapped under the aluminium plate as this might cause the calculation to be

inaccurate. It is recommended not to operate densimeter under a fan as air movement will affect the

calculation.

The weight of the aluminium plate is fully supported by the 4 cable ties. After that, press the tear

button on the electronic scale to reset the scale to 0.00g.

Put in the silver that you want to measure on top of the plate. Make sure that the water fully covers the

silver. The amount of displaced water volume would add extra weight to the electronic scale. This

weight will be divided by its own silver weight to determine the purity of the silver.

Manual calculation

Silver density is measured by its weight divided by its volume. The closer to the common density of silver

- 10.49, the purer your silver is. Two measurements must be done for this calculation.

1) The first measurement to be taken is the weight of your silver. It is recommended to measure the

silver with scale accuracy to 0.01g. Weigh the silver and record down its weight.

2) Next, measure the volume of the silver by checking how much water it displaces. Fill up the container

with water (that measures volume) until it covers the aluminium plate by 1cm and press tear on the

scale to reset to 0.00g. After that, place your silver coin or bar on top of the plate and record it down.

(For small scales like those with a maximum weight of 300g, it is recommended that the scale does not

go beyond 250g when you fill in the water).

With these two (metric) numbers in hand, you can check to see how close your silvers density is to pure

silver by:

= Silver weight / volume of water displaced by the silver

Silver has a density of10.49 gcm-3. Although you dont have to be at this exact point but you will want

to be close. For silver, the density tolerance of +/- 0.3 is acceptable. If the density does not fall within

this range, then the silver purity is questionable. However, mistakes could have been made throughout

the process. Make sure to try again if you did not get the results you liked, just to confirm the density

before moving on.


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Densimeter Calculator

I have found a useful density calculator shared by SLS members which can easily calculate the silver

density without worrying about manual calculation. The calculator has a range of +/- 0.3 tolerances in

density. You can download the zip file here.

Note from author

As the price of precious metals keep making headlines in the news, it will be soon before scammers

come in to flood this industry with fake silver or gold coins and bars and it makes sense to be extracareful when buying these precious metals. It is safer to only purchase precious metals from reliable

sources and always do your due diligence and research before you commit into buying. Only proper

education and research can differentiate between a foolish buy or a genuine buy.

Whether you are a new or seasoned investor in silver, I hope that this article has helped you to either

gain new knowledge or refresh what you already know. If you need my help with the densimeter or

calculation, feel free to contact me through email or Facebook. For those who wants to skip the trouble

of building the densimeter yourself, you may send me an email and I will arrange a unit for you at a fee.


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Finding out the silver purity for 1oz American Silver Eagle

The first measurement to be taken is the weight of your silver. It is recommended to measure the silver

with scale accuracy to 0.01g. The silver weight is 31.13g

Next, measure the volume of the silver by checking how much water it displaces. Fill up the container

with water until it covers the aluminium plate by 1cm and press tear on the scale to reset to 0.00g.

Make sure that the edges of the aluminium plate do not touch any part of the container. Otherwise, the

calculation will be inaccurate. (For small scales like those with a maximum weight of 300g, it isrecommended that the scale does not go beyond 250g when you fill in the water).


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After that, place your silver coin or bar on top of the plate and record down the weight. The water

volume displaced by the American Silver Eagle 1oz coin weighed 2.99. By inserting the two weights into

the calculator and pressing the green button, it returned a result of .999 silver. This means that the

American Silver Eagle purity is .999 silver.

Links

Digital Caliper: http://en.wikipedia.org/wiki/Caliper

Specifications: http://www.silverbarter.com/coins_specifications.html

Densimeter Calculator: https://docs.google.com/open?id=0B7BBu5MjVTJANm9YZzU0aE5XWGc

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DIY Densimeter (Cek Ketulinan Silver Sendiri)