Recommendations for lab balances

[Tom Kershaw]

After various frustrations trying to use a set of diet scales that have now given up, I'm interested in purchasing a good lab balance. I've looked at the Denver Instrument Maxx series portable balance, Ohaus Scout Pro, and a Cole Parmer own brand series online, but I'm open to recommendations.

http://www.coleparmer.co.uk/catalog/product_view.asp?sku=1142224

The PDF for the above balance mentions sealed controls and a stainless steel platform, which seem appropriate for a darkroom environment as occasional spills or splashes are almost inevitable.

Tom

 

[Nicholas Lindan]

That's pretty pricey.

I have an Escali L-600 which cost $55. They also make a 125gm model with 0.01gm resolution.

Accurate enough, and it has an auto-tare feature I find convenient.

 

[Peter De Smidt]

I'm sure those are great scales, as they should be for the price. I use an AND HL-400. You can see one at: http://www.scalesonline.com/detail.aspx?ID=55 That might not be the best price, as I didn't spend any time comparing. (I seem to remember paying about $60 for mine.) I've had my scale for a couple of years. It's worked fine. When working with Phenidone I make a percentage solution to improve accuracy.

 

[Photo Engineer]

There are several references, IIRC, given in the thread on using teaspoon measurements. I think they might help.

I bought mine at the Photographers Formulary after using one there during a workshop. They are brand name items and hold up well in the lab. I have several old balances and recently bought a surplus Kodak scale made by Sartorius.

PE

 

[Tom Kershaw]

The the major price change on the lab scales seems to be whether the scales measure to 0.1g or 0.01g.

e.g:

http://www.coleparmer.co.uk/catalog/product_view.asp?sku=1142225
or
Dead Link Removed

Tom

 

[Tom Kershaw]

There are several references, IIRC, given in the thread on using teaspoon measurements. I think they might help.

I bought mine at the Photographers Formulary after using one there during a workshop. They are brand name items and hold up well in the lab. I have several old balances and recently bought a surplus Kodak scale made by Sartorius.

PE

A portable scale, e.g. http://www.coleparmer.co.uk/catalog/product_view.asp?sku=1122066 ?

Tom

 

[Mahler_one]

About 33 bucks...no need for anything more unless you are weighing larger amounts, and need accuracy out to hundreds ( usually not needed for photographic darkroom applications )...automatic tare, and lots of other features...and, the scale fits in your pocket...a great product

http://www.myweigh.com/scales/pocket-and-mini-scales/400z-performance-scale

 

[Tom Kershaw]

I have been using those cheap scales, and am not inclined towards another set.

Tom

 

[Mahler_one]

Why Tom? When used as directed, the scale has never failed.

 

[Jim Michael]

I think I paid about $15 for an AWS AMW-100 from Amazon, resolution is 100 x .01g so good for small quantities. It has a tare mode so you can place a piece of paper on and zero it out.

 

[Kirk Keyes]

That Ohaus Scout Pro is a great scale. They have some in the laboratory where I work.

I've got two digital "jewlers" (i.e. dope) scales that I bought from ebay for about $20 each. One does 100x0.01g and the other is 1000x0.1g. I've checked both with certified weights and they are as accurate as the display allows. That is, they are right on. I really like the 100x0.01 scale, but the 1000x0.1g scale is actually smaller than the other one, and when weighing large amounts, you really need a good sized pan, not one that you can hide in the sleeve of your jacket...

Maybe you can describe what you want in a scale, and what you did not like in the kitchen scale you had?

 

[Kirk Keyes]

Oh, never get anything with an "autotare" function. You may need to look something up halfway through wieghing something out and it can take a minute, and if it autotares you loose the weight of what you had already partially weighed. I have a kitchen scale like that and it annoys me to no end...

 

[Kirk Keyes]

The the major price change on the lab scales seems to be whether the scales measure to 0.1g or 0.01g.

e.g:

http://www.coleparmer.co.uk/catalog/product_view.asp?sku=1142225
or
Dead Link Removed

Tom

Yes - and you can get just about any combination of max weight and resolution in a scale, you just have to pay for it.

I'd love to have a Scout Pro that reads to 0.001g, but I'm not ready to pay that much yet!

Can you tell us what weight ranges you want, and how many decimal places you need, and we can help find something for that.

 

[Tom Kershaw]

The scale I was using was not really robust enough for my usage. Any sign of moisture would creep inside the button battery compartment and cause corrosion etc. I want a balance that I can sit down on the workbench and be confident that it will work correctly, and that has a reasonably sized weighing platform for larger volumes. Thanks for the comment in favour of the Ohaus Scout Pro; I'm inclined towards the 0.01g to 600g model, to cover a reasonable range of measuring requirements, e.g. Phenidone and Sodium Sulphite.

Tom

 

[Tom Kershaw]

Can you tell us what weight ranges you want, and how many decimal places you need, and we can help find something for that.

Do you have any experience with the Sartorius or Denver Instrument models?

Tom

 

[Photo Engineer]

Kodak uses Sartorius extensively and they are quite good.

Many models that plug in (not battery models) will not lose the tare.

PE

 

[Tom Kershaw]

Many models that plug in (not battery models) will not lose the tare.

PE

And so will keep reading 25.40 grams while I rummage around for another container of the compound to get to 30.00 grams?

Tom

 

[Photo Engineer]

Tom;

It depends on the model. If mine is in battery mode, it loses tare and then will shut off. Bummer. If plugged in, it keeps humming along.

PE

 

[Tom Kershaw]

One of the attractions of the 'Denver Instrument' model I linked to previously is that the marketing info claims the balance has been made resistant to splashes with sealed controls, however several of the other manufacturer's balances appear to have sealed controls, so perhaps the 'Denver' model is not much different. The own brand Cole Parmer series instructions make explicit reference to avoiding any splashes or moisture, which makes me somewhat nervous about suitability if used in a darkroom.

Tom

 

[nworth]

You have the right idea. Spending a bit of money and getting a really good scale is a very worthwhile investment. I've had my Ohaus Dialogram for almost 40 years, and it continues to give accurate, reliable service. As for brands, I don't know. Using a brand that is well respected in the industry would probably be a good idea. Study the descriptions and select the scale with the features that best suit your situation. I find that a real pan works better than a flat plate. Keeping tare may not be very important, since you reset it almost every time anyway.

 

[Mahler_one]

No argument about a scale with a larger pan being a bit more convenient than one with a pan that can fit in one's sleeve....however, for many of us a smaller pan is perfectly adequate for the applications that one uses, i.e., relatively small amounts of materials to be weighed once every few weeks or so. I guess one picks the instrument one needs for the task on hand, and uses it until such instrument proves to be wanting.

I agree about the auto tare function....good point.

Ed

 

[Ian Grant]

Kodak uses Sartorius extensively and they are quite good.

Many models that plug in (not battery models) will not lose the tare.

PE

I used to use Sartorius balances, they weren't bad, I had a set that weighed to 4 decimal places - 0.0001 of a gram, I also bought two Mettler balances, they weighed to 5 decimal places, I paid about £3,000 for one set 20 years ago They paid for themselves quite quickly

Surprisingly my main balance now back in the UK is an ancient but very accurate Griffin & George beam balance, accurate to 0.005 grams, (I have certified calibration weights) although I do have some 0.1 gm electronic scales (which seem to have gone faulty with lack of use).

I had a good contact for scales, when he was still a service engineer he came out on contract to do our routine (& mandatory) external certification, we had about a dozen scales. At that point he was setting up on his own., and struggling slightly, I showed him just how many sets of scales there were in the Jewellery Quarter in Birmingham and he hasn't looked back since. I'll try and find his details for you Tom, he usually had good second hand scales, which he re-conditions, services, & re-calibrates.

Ian

 

[Tom Kershaw]

I had a good contact for scales, when he was still a service engineer he came out on contract to do our routine (& mandatory) external certification, we had about a dozen scales. At that point he was setting up on his own., and struggling slightly, I showed him just how many sets of scales there were in the Jewellery Quarter in Birmingham and he hasn't looked back since. I'll try and find his details for you Tom, he usually had good second hand scales, which he re-conditions, services, & re-calibrates.

Ian

I'm ok with looking at new balances as I don't need a super sophisticated model or 0.0001g type precision.

Tom

 

[Ian Grant]

Andrew sells all sorts, new & second hand, not all our balances were that accurate, just the one's used to weigh 0.2g samples of Precious Metals for Assay

If I can get his number I'll PM it to you, he's a very genuine guy and would give you only what you need, and at a fair price He had a website but it's a while since I last saw him.

Ian

 

[CBG]

I have two scales; one is a plain vanilla Escali that will weigh up to 7 or 11 pounds, I forget which, and weighs to 1 gram, with a tare function. That takes care of 95% of my needs. The second scale weighs down to .01 gram and has a max of maybe 250 grams. That is for the few items that need small quantities like phenidone.