How can a kitchen scale measure volume in mL or fluid oz?

[737liz]

If you read the listing details it shows you this.
I assume it only measures volume for a set number of substances That have had their volume to weight info préprogrammées into the machine. Sounds like a lot of unnecessary fiddly button pushing when most people have a measuring cup somewhere in the kitchen.

Edit: looks like water and milk are your only options... how very useful.

 

[Maria D]

The metric system or SI (Système International) units relates length, volume, and mass by setting 1 cubic centimeter to equal 1 milliliter and then defining a 1 gram to be the mass of 1 ml (or cm^3) of water at its highest density which occurs at a around 4°C. Since the density of water doesn't vary much from 4°C to room temperature (~20°C), it's safe to say that a kitchen scale would give you an accurate measure (well within its own tolerances) of volume of water just by measuring grams and calling it ml.

The m ml setting appears to be for milk. Since the density of milk is 1.2 times the of water, the scale would weigh the milk in grams and then divide by 1.2 to display the volume in ml.

The scale isn't measuring volume at all, it is measuring mass and then converting it to volume for water or milk. I wouldn't spend more for a scale that did this. I can't think of a recipe I've ever used that called for liquids to be measured in anything but volume.

 

[Garnetgirl]

Excuse me, but accuracy matters to some cooks.
Expecting a measuring device to be accurate has been replaced by settling for and accepting "close enough".
And we're expected to memorize that chart of various densities Karl posted?
What about things not on the chart?
And someone is going to use these scales to weigh the volume of flour , then wonder why the recipe failed.
This whole idea is just absurd, and insulting.

IMO, close enough is not good enough when purchasing a device designed to measure someting!
Since it is not accurate for the volume of everything (every liquid and every solid from lead to feathers) don't put a volume button on a weight scale!
What a capitulation to ignorance, sloppiness, and laziness!

The dumbing down continues.

Today I'll look for, and order, a scale that doesn't have a button that lies.

I never said that accuracy doesn't matter. I also said a scale cannot and does not measure volume.

But there such a thing as 'close enough'. To reiterate, as other posters have said - their recipes are successful even if some assumptions or approximations are made.

In the kitchen, I use measuring cups and spoons for my recipes. A measuring cup is not as accurate as a graduated cylinder or volumetric flask, but while I use them in the lab, I don't in the kitchen. I measure carefully and my recipe results are successful.

But all measuring instruments have inherent error in them.

For example, the scale that @Tartansparkles used fluctuated between 99g and 100g. 1% error. How accurate and precise for measuring weight is the scale you bought? You would have to calibrate it to know the answer.

The chart that @Karl_K provided shows only a 3% error would result from weighing milk, for example, though it's not something I'd bother with. Just use a measuring cup.

 

[mellowyellowgirl]

I find the myth that you need to be mega accurate when baking..... well a myth.

I make a lot of chiffon cakes and experiment a lot. Many of the cakes I make up in my head so will decide on the spot whether I add an extra 5 or 10 grams of flour, an extra 10 or 20 mls of liquid. It still works and the texture is not that discernably different until you're using say 150g of flour vs 200g flour.

 

[kenny]

People vary.
This one loves accuracy.
For me it's a thing.