Teaspoon measuring

[Photo Engineer]

classic....the scientist vs the engineers.

For whatever it is worth any engineer worth his salt will immediately point out that a product or process that is not robust against minor variations is worthless...or simply put, un-economic, not feasible.

and... sheesh! guys, the OP asked a simple question....and all but one jumped on him for measuring his chems with a teaspoon. Nice. What a nice bunch of helpful folks....:rolleyes:

For the OP, I looked up the density of Ammonium cloride and found it to be, 1.5274 g/ml . I figure a standard teaspoon is 5ml so, I get 7.6 grams per teaspoon. In a similar fashion, I get 8.5 grams per teaspoon for sodium citrate.

I would have to ask "What crystal form are you using for these densities? Is it the pure crystal or the ground powder?".

And here we go again!

PE

[gainer]

I would have to ask "What crystal form are you using for these densities? Is it the pure crystal or the ground powder?".

And here we go again!

PE

If it is that critical, the OP will find out soon enough by experimental test of the hypothesis "This amount should work."

[eclarke]

After all this, what if the prints are poorly seen, lit flatly and are boring subject matter??..Evan Clarke

[Sirius Glass]

Actually I did find it in post 9 just didn't realize it would cause such a firestorm!

You did not cause the firestorm. There are those here that seem to have a "god given right" to spread the word that accuracy is not important and anything goes. Unless supplied with the appropriate caevats, people who come to this site will be mislead and then with bad results will leave photography.

Please feel free to ask all the questions you want.

Steve

[Photo Engineer]

If it is that critical, the OP will find out soon enough by experimental test of the hypothesis "This amount should work."

And by weight it would work the first time!

PE

[Formulary/Bud Wilson]

We at the Formulary would like to make the following offer;

1.If anybody would like their order of 100 grams of Metol spooned out of our drum, instead of scaling it for you please let us know when you place your order. This will apply to all chemicals not just Metol.
2. But when you recieve it and find that your 100 gram package only contains 97grams please don't call and complain.
3.If you order a 50# package of Sulfite we can scoop it out to get close or scale it out as we always do. If we scoop it out for you and you only get 49 pounds please don't call and complain.
4. when you order any of our kits, which are prescaled out formulas that we put in a kit box for you, and the formula has 5 chemicals in it please let us know when you place the order if you want it scaled or spooned. Each of the 5 chemicals could be off by what 2%. Please don't call us when the formula isn't the same as you ordered last time.

We scale everything that goes out of this company. There are other ways of doing it, but scaling your orders is the right way to do it. We don't get complaints that our products aren't the right quantity.

What you do with the chemicals when you get them is your business. Supplying them to you in the proper quantity is our business, and we Scale the chemicals.
But as I said anybody that wants us to spoon out your kits just let us know.

By the way thanks all for your support.

Bud Wilson
Photographers Formulary

[fotch]

This has been a very heavy discussion. I have weighed the alternatives and like the scale model.

[Photo Engineer]

If it is that critical, the OP will find out soon enough by experimental test of the hypothesis "This amount should work."

After thinking this over, I realized the full implication.

In essence Patrick is saying here that his method won't work. You have to test to see if the teaspoon method will work in any given instance, and/or you have to fiddle with the amounts used to get it to work properly.

This is going to cost time and also use up some amount of chemistry and light sensitive materials, (film or paper) until you get it right. And, based on what I have found appears to be true in variability of weight / unit volume from batch to batch, that you have to do this every time you buy a new bottle of chemical.

This is a pretty stunning indictment of his own method, by the person who advocates it.

Keep at it until it works guys. Then, you have it pegged! By then you may have run out of patience, chemisty or exhausted your budget for film and paper, or all of the above.

PE

[David A. Goldfarb]

And even if you use a scale, be sure to calibrate occasionally.

I once got into an awkward situation splitting an order of silver nitrate with someone who lived on the other side of the country. He weighed his portion when it arrived and said that he thought it was short. I weighed my remaining portion, and it seemed right. I checked my scale with a 100g calibration weight, and it was off maybe by a gram, but not enough to create the discrepancy that he had noticed. Then he confessed that he was using a $20 scale he got in a head shop, and mine was probably right. You would think head shops would sell very accurate scales, there being some rough characters in that trade.

[Nicholas Lindan]

If anybody would like their order of 100 grams of Metol spooned out of our drum, instead of scaling it for you please let us know when you place your order. This will apply to all chemicals not just Metol.

Fine by me. I expect you will pass on the cost savings of not having to weigh it out.

And, I expect that you will not require me to return the extra if the 100g package of metol actually contains 103gms.

If the discount is reasonable, and the scooping fair, how should I indicate this on my next order? [insert smiley if you need to]

"It's funny, you know: when all is said and done, it all comes out even to the last farthing."

-- My Uncle, on his death bed.