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Notes on using a Hanneman SG Balance


#1

I was reading the IGS article on SG measurements today. Great article! Thanks. I do have some notes on using the Hanneman Balance. I have one, use it, and it’s a fantastic device! I’ve been on the phone with Hanneman and the person I spoke with was very helpful.

You probably have to have one or be looking at one online to get what all this is about.

Yes, zero it every time. Even letting it sit overnight with the left side trays in the water will change the readings. In fact, don’t do that. I have a gallon jug of distilled water and I fill the water beaker, make my measurements and return the water to the gallon jug. Keep the beaker upside down when not using to keep out contaminants.

Zeroing the beam can be too much fun! Hanneman supplies a slide weight for the left side of the beam. If you use it to zero the beam, and bump the beam after, start again, it will move. I went to the dollar store and got some small clothespin type things. They don’t move if you bump the beam. So try taking off the slide weight and putting on a small clothespin instead.

On the right side there is a zero line and the entire right side can move up and down a little. It is a lot of fun to use that sooooo … I made a Dymo label that looks like this, …0… and put it on rotated 90 degrees. You don’t have to use the zero mark supplied. It’s a relative thing. If I zero to the 2nd dot down from 0, then that is always my zero point for this one specific time. If next time I zero the beam and it is at the first dot up, that is my zero point for that specific time. Think about it… if you can move the entire right side zero up or down, why not just balance the beam as close as you can and always use that same dot for that specific time?

Hanneman supplies a series of weight hooks to use for balancing after you put the stone in the upper tray. I made some of my own too out of staples of different lengths. Open the bottom of the stapler as if to put something onto a cork board and eject a few staples. Bend one end over into a hook shape, next one, do the same and snip a little off the length, make a few more shorter and shorter… It’s a lot easier than using the salt method as supplied, less mess too. Agreeable, there will be times that only the salt will balance the scale with the stone on the top tray. I cant count the number of times I knocked the whole mess down and had to clean up salt and start again.

There is a magnetic thing with the staples and supplied weights. Use a plastic tweezers with them.

I’m sure those who have used the Hanneman have other ideas for use and I hope to hear them.

Regards,

Roger
GIA AJP
GIA Colored Stones
IGS almost certified… lol


#2

I have not used the Hanneman SG balance, but I’m familiar with its construction and use. I am a great fan of Dr. Hanneman, have read his Affordable Gemology and consider it one of the great works of gemology. I use lots of his techniques. All that said, I think the SG balance has mostly been superceded. Back in the day, there were no digital scales. Now one can get a small digital scale accurate to 0.01g. It’s a simple matter to put a gem on a piece of light fishing line or string and put it in a small plastic cup to weigh it. Fill the cup with water, tare it, and weigh the gem while sitting on the bottom of the cup. Then weigh it suspended in the water. The method and calculation is a little different from the classical method illustrated in most gemology books, but what I’m describing is quick and dirty and accurate enough. The Hanneman balance IS direct reading, and that’s a convenience, but it certainly is not portable, whereas what I’m describing is portable and easy and pretty accurate. Just another opinion. I do think we still have a school of thought in gemology that relies too much on the refractometer. Esp. for rough stones a rough SG and some other observations (dichroscope, polariscope) are often all that is needed. Just another opinion.


#3

Yes, agreed the Hanneman is not as portable as a digital scale as you describe. Have you found temperature to be an issue in your use moving it about? I keep a gallon of distilled water next to the Hanneman and like to set the sample on the Hanneman to let it temperature stabilize for a while first. I may try reading a stone in my normal method, then using warmer water and then colder water to see how much the variance is if any.


#4

staples are ok but with real fine copper wire you dont have the magnetic problem.


#5

Great idea!!! Thanks


#6

HI Rogergthree
I also use a Hanneman balance regularly. They are very accurate and look the part when you are demonstrating how to measures SG.
I do not use the salt either as where I live the salt is always damp, instead, I am using very fine sand in a small puff bottle. This way you have fine control of the weight.
Instead of buying distilled or demineralised water, I use rain water instead and always add a drop of detergent to the beaker. This helps with wetting the stone to give a more accurate result and I find it does not alter the SG reading in any way.
Reards Trevor