Darkroom Scales

[tgtaylor]

I'm in the market to replace my well-used triple beam balance. What's some good ones to choose from? I need to measure to the 1/10th gram. I've been eyeballing this on at B&H http://www.bhphotovideo.com/c/product/348340-REG/Ohaus_CS200_CS200_Standard_Darkroom_Scale.html

Thomas

[Taija71A]

Ohaus, makes very nice Darkroom Scales...

Just FYI Thomas, I have used an older model of this Ohaus Scale (LS200) for many years... With nary a problem.

If my scale was ever to 'fail me'... I would definitely replace it with a CS200.
Enough said... Just buy it. Highly Recommended! :)

-Tim.

[Jim C.]

Any reason you'd want to go electric rather than a mechanical scale ?
I've used a Ohaus triple beam for decades they take a beating and keep on measuring
no batteries or wall wart power supplies needed.

[tgtaylor]

I am also considering an Ohaus triple balance. What I like about the mechanical scales is that they allow you to measure 1/20th gram mark unlike the (affordable) electric sales which measure in 1/10th gram increments.

Thomas

[Taija71A]

Ohaus of course, makes beautiful Mechanical Triple Beam Balances...

But, I don't 'believe' that they come in (0.05 g Accuracy)...
*In the size (200 g Capacity) -- That you originally cited.

Thomas, what are you trying to mix that requires 0.05 g accuracy?
Phenidone? Just curious...
--
If you 'truly' need (0.05 g Accuracy)...

Have you given thought to 'perhaps' preparing (beforehand), a very dilute
(1% 2%, 5% 10%) 'Stock' Solution of that particular chemical? Just a suggestion...


Any reason you'd want to go electric rather than a mechanical scale?

If size and/or weight considerations are an issue...
Electronic Scales are smaller and lighter.

Best regards, -Tim.

[LabRat]

That Ohaus Electronic Scale linked is a good price, but do further research of that model to see what the resolution of the scale steps are... (There are different models/different price point units that have more/less "simplified" scales...) I remember a while ago that the suitable Ohaus model was hundreds of dollars... 10ths/gm is good for foto use... (20th/gm models are much more $$$, and very sensitive to vibration and even drafts in the room!!!)

The measuring range is OK if you are making a liter or two of solution, but for larger amounts, you will be back to your triple beam!!!

Triple beam balances get very sluggish <0.3/gm, so like Tim said, you can mix smaller amounts by making stock solutions... (Phenidone, restrainers, etc can be mixed that way...)

My "daily driver" is an old Ohaus "Harvard" balance, that requires separate weights, but will weigh out 0.1/gm to 5lbs... And I can just add another cup to the other side to balance out the tare weight so something less to think about... (FYI/ Good measuring cups are a package of paper or styro cups... Usually about exact equal weight cup to cup from the same batch...)

And don't even think of buying cheeep digital no-name scales... I bought a cheeep pocket digital scale from a head shop to set-up a few turntable tracking weights, (then to the darkroom to weigh out small chems), and 3 died within days, so I had to return them... Finally got a good one, but it only lasted a few months... (Don't bring one to your "big score"!!!)

Steve K

[Taija71A]

That Ohaus Electronic Scale linked is a good price... 10ths/gm is good for foto use...

Agreed in full 200%.


... but do further research of that model to see what the resolution of the scale steps are.

The Ohaus CS200 is 0.1 g... Readability, Repeatibility and Linearity.


... 20th/gm models are much more $$$, and very sensitive to vibration and even drafts in the room!!!)

"Akchoo!!!" :D


... (FYI/ Good measuring cups are a package of paper or styro cups...

+1. Coffee filters and paper cupcake liners... Also 'work in a pinch!'

I am pretty sure that the CS 200 also has a 'Zeroing Range'.
My Ohaus Unit certainly has this Function.

Steve knows... Darkroom Scales! :)

[tgtaylor]

Well here is the scale that I finally went with: https://farm1.staticflickr.com/445/19258108781_da8dc9b9bc_z.jpg

It's the Ohaus CT200-V which, unlike the CS200, is readable to the 0.01gm which I commonly need to measure to since I mix most of my formulas from scratch for single use and the math usually goes to the 2d decimal place. It is shown above reading the 1.97 gm weight of a plastic disposable condiment container for salsa which is ideal for measuring small qualities of chemicals such as silver nitrate or tartaric acid. Incidentally this weigh agrees within a 1/10 gm with my triple beam which is an Ohaus knock-off but unlike the triple beam is repeatable. It comes with a plastic scoop for larger quantities which is much more convenient than using coffee filters. I picked it up off ebay in unused condition with box, calibration weights, etc for $100.

Thomas

[Tin Can]

I went the cheap way and think this will be fine for my usage. I got it yesterday, very nice device and it is calibratable. Already used it, it works well and is warrantied 10 years.

http://www.amazon.com/gp/product/B0012LOQUQ?psc=1&redirect=true&ref_=oh_aui_detailpage_o01_s00

In my past I worked with analytical balances, such as these, that are way overkill for my current purposes.

http://www.amazon.com/Ohaus-Pioneer-Analytical-Internal-Calibration/dp/B00T2KUUA4/ref=sr_1_5?s=industrial&ie=UTF8&qid=1435552959&sr=1-5&keywords=analytical+balances

[Taija71A]

... It's the Ohaus CT200-V...
... I picked it up off ebay in unused condition with box, calibration weights, etc for $100.

'Good spot' Thomas.
Used, but in unused condition is always nice! :)


... And think this will be fine for my usage. I got it yesterday, very nice device and it is calibratable. Already used it, it works well and is warrantied 10 years.

Amazing price Randy!
Yes, it should be just fine for your usage. Enjoy!

[mdarnton]

I've been using one like Randy's but with a 500gm limit for some years now It works fine. I have one for the darkroom, and one for the shop, to weigh bows. Never a problem.

[Drew Wiley]

If I was a real chemist I'd buy a serious electronic scale from a scientific supply house. But since I'm just a darkroom alchemist, the basic triple beam Ohaus unit
has been plenty accurate and reliable for my own needs.

[Jerry Bodine]

...the basic triple beam Ohaus unit
has been plenty accurate and reliable for my own needs.

Same here. The only thing mine lacks is accounting for tare weight, but that's only a minor inconvenience. Besides, I'm not in a race; there is no production-type assembly line conveyor belt in my darkroom. Robotics begone!

[mdarnton]

By the way, I have two triple-beam Ohaus also. One's modern, one a beautiful 100 year old cast iron thing with a milk glass plate on it that I was so happy to find, 30 years ago. Haven't used them since I bought a $15 electronic scale. Too hard to store, too much bother to use, too fragile, too big. Too much bother. :-) Electronic scales are the best thing ever!

[Tin Can]

I agree, and even a $250 Ohaus® - 1650-W0 - Triple Beam Balance only measures to 0.1 g and I needed 0.01g for Phenidone.

I also use a Costco electronic food scale, $14, 5kg capacity accurate to 2g which is good enough for all my heavier than 50 gram requirements, Stainless platen. Never used for food.

[Drew Wiley]

For critically small amts I simply mix up a stock volume of the tricky ingredient in dist H2O then dilute it down as needed. It's more accurate that way than trying to weigh the eyeball to a gnat dry.

[Peter De Smidt]

The issue with phenidone is that even with a 1% solution, you still need to be able to measure a really small amount. I make my Dimezone-S 1% solution with polypropylene glycol. It lasst a very long time. I'm still on the bottle I mixed in 2009.

[Drew Wiley]

Well, serious electronic scales are abundant too. I just like the fact that the good ole triple-beam can sit in my sink while I weigh out whatever, and simply be
rinsed off afterwards. I can't seem to make pancakes either without some flour going where it doesn't belong.

[Maris Rusis]

Ebay was my friend when I bought "Digital POCKET SCALE" 300g capacity reading to 0.01g for $15.00. I suspect it's an example of what is known as "drug dealer scales" but it works a treat with photo chemistry.

[tgtaylor]

The issue with phenidone is that even with a 1% solution, you still need to be able to measure a really small amount. I make my Dimezone-S 1% solution with polypropylene glycol. It lasst a very long time. I'm still on the bottle I mixed in 2009.

I agree. Also for some uses, for example certain gold toners which must be used the same day they are mixed, its not practical or economical to dilute and for others its not practical to store a large quantity of a compound for future use. Everything is better freshly made and having an accurate scale that can measure small quantities is indispensable.

Thomas

[Jim C.]

Same here. The only thing mine lacks is accounting for tare weight, but that's only a minor inconvenience. Besides, I'm not in a race; there is no production-type assembly line conveyor belt in my darkroom. Robotics begone!

I use a Ohaus triple beam for work all the time and for the longest time I suffered without a tare bar till I got fed up
wadding clay on the pointer end to tare off containers. I called Ohaus and they sell the tare bar as a part.
You may want to give that a go, it will entail that you add weight underneath the weighing platform/pan.

[Jerry Bodine]

Thanks, Jim. Suggestion noted.

[Bill Burk]

I got an Ohaus scale a few weeks ago and have been looking for weights for it... Until I get them I will be using Risk pieces.

[Drew Wiley]

Beach shoes work well for extra weights. You can fine tune them by how much sand you pour out. And you never know what kind of miracle developer you'll accidentally discover when some little sand flea or bit of flotsam gets into your chemicals.

[Bogdan Karasek]

I went the cheap way and think this will be fine for my usage. I got it yesterday, very nice device and it is calibratable. Already used it, it works well and is warrantied 10 years.

http://www.amazon.com/gp/product/B0012LOQUQ?psc=1&redirect=true&ref_=oh_aui_detailpage_o01_s00

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I also bought an identical digital scale at a "head"shop. Triple beam scales are fine if you are measuring out larger quantities but when I have to measure 0.5gr of Potassium Bromide, I go with the digital scale. Try getting exactly 0,5 gr with a triple beam.......

[Bill Burk]

Beach shoes work well for extra weights. You can fine tune them by how much sand you pour out. And you never know what kind of miracle developer you'll accidentally discover when some little sand flea or bit of flotsam gets into your chemicals.

Ordered a set of weights with both "grain" and "gram" pieces.

Not hoping for a miracle developer that might give 2/3 more stops speed. I think that's pointless. Everybody is doing that. I'll be doing different things. I'm more interested in going the other direction. Seeing the effect of adding too much restrainer, or verifying the story I read that you can leave out the Hydroquinone in D-76 and get the same results (It just goes bad faster).

[tgtaylor]

I had the opportunity to use my new Ohaus CT200 scale for the first time yesterday morning preparing Sodium Thiocynate toner. Worked marvelously – I only wish I would have gotten it sooner. The formula called for 0.10 gm of tataric acid and as soon as the tiny grains of the acid hit the container, the scale started counting-off the 1/100's of a gram that were in. Very accurate which will allow not only for more accurate formulas but will also save you money by using only the amount chemistry necessary. I am particularly impressed with the Tare feature and the and the provided scoop for measuring. The unit stores compactly in its Styrofoam casing for storage for which I reinsert the shipping bracket and slip into the cardboard outer box.

Curiously my scale came with 2 200gm calibration masses. At first I thought this was a packing error as one should have been a 100 gm mass. But the manual calls for calibration with the 200 gm mass but a 100gm mass is also available as an accessory.

A very good and highly accurate scale.

Thomas