Wolfram
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Scale
How do you people check the weight of things when most of you dont have any propwer scales. Scales seem expensive if someone has one maybee they could
tell me where to get one...
Please..
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Haggis
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There are many sources of scales, and most people on this forum (that I know of) own a decent lab scale, myself included. Any store that sells lab
supplies (online or in the real world) should sell scales as well. Off the top of my head, Al-Chymist, United Nuclear, American Science and Surplus
are common suppliers with scales. A simple google search will bring you scale suppliers by the page load.
Great ideas often receive violent opposition from mediocre minds.
<b> <a href=\"http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xEE41A2B1\">PGP Key</a> </b> 0C0A 7486 B97F
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Iv4
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I dont have a scale either
I usualy use the old fashioned way and balance a small cup of water and the thing to be weighed on a scale and calculate from there.I know tap water
is'nt 1 gm/cm but for the price(nothing)cant really expect much more.
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jubrail
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Two good options
First option is to measure via solubility. If you know what the substance is then look up its solubility in a certain solvent. With that you may
determine the amount you have. If you need to measure out a certain amount from a whole that you know the weight of (i.e. you need 25mg of a reagent
that you have 1g of) then dissolve and recrystallize the proper amount. In the example above you could dissolve the 1g in a liter of solvent and then
recrystallize 25 mL.
The other option is to build your own scale based on electrical current. Check out Rhodium's site near the bottom of the page for a workup on
this.
Rainbows & Butterflies Forever
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Quantum
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I own a scale that is very cheap from Old Will Knot It can only go up to 100g but its accurate with 0.0g Its only 28 bucks!
Are you THE Wolfram or just someone with the same name?
[Edited on 6-12-2003 by Quantum]
What if, what is isn\'t true?
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T_FLeX
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For right now I've been using a powder scale. I found mine at a yard sale of a hunter for only 5 bucks.They are used for measuring gun powder.
The only bad thing is you have to convert grains to grams, and it can't measure something like a beaker only powder.
This is a picture of what mine looks like.
http://www.cabelas.com/information/Hunting--Optics/Hornady-M...
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SweetNLow
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Typically for lab applications, you'll want a scale that has a large capacity and also good precision. Higher precision scales are expensive, but
if you want something that is cost-effective and produces excellent results, then look no furhter than the iBal 201. Its capacity is 200g and has an
accuracy of 0.01g! It cost around $100.
Check it out...
http://www.myweigh.com/mediumscales_ibalance.html
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Mumbles
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I happen to have the iBalance 201, and I must say I do enjoy it. It works well in test tube quantities. It does everything I need it to, except for
very large things, such as rocket engines.
My only complaint is that it beeps everytime you change modes or tare. Its nice to know if I accidentally hit a button, but it gets annoying fast.
The mode is pretty small too, but those are things that I can live with. Similar featured scales cost twice as much in most catalogs I've seen.
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Hermes_Trismegistus
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TRIPLE BEAM!!!
Lasts forever, resistant to temperature changes, chemical spills moisture etc etc etc....infinitely adjustable, you can make repairs yourself if
neccesary and it NEVER gets the dreaded continuous creeping digit syndrome.
eighty bucksbest friends forever
Arguing on the internet is like running in the special olympics; even if you win: you\'re still retarded.
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tom haggen
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Reply
I have a shitty scale for weight grams.
but I have access to a one of my drug dealer friend's digital scale when nessecary. silly stoners scales are for chemists.
N/A
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chemoleo
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Hermes, if you know, could you sum up in two works how that scale of yours works? I also have this creeping digit syndrome, and it's very
annoying.
Where do you get it from?
Thanks, C.
Never Stop to Begin, and Never Begin to Stop...
Tolerance is good. But not with the intolerant! (Wilhelm Busch)
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hodges
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I have one of those old pocket-sized metal postal scales - the kind with a clip to hold the envelope and where you read the mass on a circular scale
based on the angle it makes. Usually I clip this to a test tube and note the initial mass, then slowly add solid chemical until I get the difference
I need. After doing that a few times, I have gotten a good feel for how much volume commonly used salts such as NaHCO3, MgSO4 hydrate, CaCl2, etc
take up at the granule size found in common household products. Resolution is only around 0.5 grams, so I try to use amounts of 5-10 grams so my
error is less than 10%. I feel that with common household products I really don't know the purity much closer than that anyway.
I did recently see a 100 gram digital scale with 0.1g resolution on E-Bay for less than $30 including shipping so I have ordered one - have not
received it yet. Likewise I found a pH meter with 0.01pH resolution with calibration buffer solution for under $30 counting shipping, which I also
ordered. Neither of these is lab grade material, but like I said nor are the chemicals I am using. Its going to be a lot more accurate than I'm
used to using the postal scale and indicator solutions, though.
Back when I used to make black powder I did it by volume. I remember 10 parts KNO3, 3 parts C, and 2 parts S was the most effective mixture I found
for wrapping in aluminum foil and twisting to make "sparklers".
Hodges
[Edited on 12/20/03 by hodges]
[Edited on 12/20/03 by hodges]
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mericad193724
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Over the summer I borrowed a high quality lab scale from my school (.01g). I now need to buy my own scale and they are REALLY expensive.
I was checking out ebay and there are LOTS of those inexpensive Jewelry scales for sale.
This one looks OK:
http://cgi.ebay.com/WM-100x0-01g-Gram-Carat-Digital-Jewelry-...
Are these scales really accurate to .01g, or are they just a cheap rip off? Anyone have experience with these?
Mericad
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Blind Angel
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Got a Mettler H10 from eBay for 5$ (+45$ of shipping). These are sturdy as hell, it came in the mail and its still good an calibrated at ±1mg (I'm
loosing a digit there but I'm rarely using the 0.1mg range). Somebody here compared shipping these scale by mail to using a rocket to send swarzozki
crystal, but still it work very well. Good deal.
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stricnine
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I have got a old book for kid chemistry where it shows how to make a scale from kitchen food cans, one nail, three paper clips and a couple of cotton
string yards. I made it (myself!) for a school laboratory not long ago, and it it turned out to be wickedly sensitive (far less than 0.5 g),
especailly when the joints were oiled. The only thing you need is a set of calibrated weights, something that can be done easliy with a) water, b)
pieces of copper or copper wire cut to different lenghts. Of course it will corrode with time, but you can make it at zero cost.
I am getting old. I used to push it aside with one hand... now I need both!
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stricnine
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If anyone wishes to get details, I could scan and send the stuff.
I am getting old. I used to push it aside with one hand... now I need both!
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BeerChloride
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HODGES:
I think I know the ph meter your'e talking about - I've been thinking of getting one. I saw one at "daydots" for $26. Or is where you got yours better
priced? Wait a minute, yours comes with a buffer?
Also, I saw a nifty little postal scale at Target for like $8. It only goes to a gram sensitivity, though.
If I were to build a mechanical scale, I would mount a small beam transversely on a razor blade for a pivot using steel epoxy, and go from there...
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