A strange problem with BWT Initium 2.5 l filter’s scale

Although I've come to find a lot of uses for my kitchen scale, the ones that immediately pop into mind are:

• Exact measurements. When a recipe calls for a cup of baby spinach, for example, that's going to be hard to measure. Not going to be a problem if you're dealing with weights. This is extremely important with baking, where exact measurements are absolutely necessary. Ideally, the recipe would have both, but if not you can often convert via the nutritional info on the bag - it'll say something like 1 cup (28g). A cup of flour varies wildly depending on various factors, for example whether or not it was sifted.
• Portion control. I helped my wife do Weight Watchers before our wedding, and I can't imagine trying to figure out 1 portion (3oz) of lean meat without it.
• Learning. I'll weigh a piece of meat before and after cooking it to see what kind of weight loss I get from moisture, for example.

When buying, you want to think about the following:

• Capacity. Cheap models often only go to 5lbs, whereas more expensive can hit 10 or 15. Becomes important when you're cooking in bulk, may not be important depending on your cooking habits.
• Digital vs balance. I don't trust balance (analog) scales, they're too easy to have become uncalibrated, and I don't want to be calibrating every time I need to use it. Digital scales are easier to read, and very easy to go between US standard and metric measures. Also, digital scales have a tare feature, which is invaluable (as KeithB pointed out).
• US standard/metric. You definitely want a scale that can do both, recipes may have either. Most scales should handle this.
• Plate/bowl. I find that scales that come with a bowl are unnecessary, I prefer one with a nice large plate that I can put my own bowl onto. With the tare feature that almost all digital models have, you can zero out your weight so you can pick any bowl to meet your needs. The larger the plate, the better, so you can fit more stuff on it if you're not using a bowl.

As far as price goes, I think $20 is too cheap, and is likely to become unreliable quickly, if not immediately. That said, I think over $100 is too much as well, that's likely to be based on design or name. My current scale cost me about $50 and works great, and I check its calibration regularly and haven't had a problem yet.

One specific example from our house - I make smoothies every morning from 20 oz frozen fruit, 10 oz soy milk, 6 oz greek yogurt. My wife is following a very specific nutrition guide right now, so I then split it into 12oz for her, 24oz for me. Getting her nutritional info right without a scale would be all guesswork (and I've come to learn, through using my scale, that my guesswork used to be pretty far off - it's much better since I started using the scale regularly).

Assuming you bought a rice cooker designed by a Japanese company (and apparently even other brands tend to meet that market's expectations), the measurement is 1-gou, slightly more than 180ml, which, by no coincidence, is also the typical measure of a wooden sake, cup, and is closely associated with a historical sake bottle size (approximately 1.8l)

http://en.wikipedia.org/wiki/Masu_(Japanese)

It turns out that this amount, 1 gou of dried rice, neatly corresponded to a typical serving of rice. In practice, most contemporary Japanese eat about 1.5-2 gou per day; 1 gou of dried rice cooks up enough for 2 Japanese adults for one meal if you have several side dishes. There are other measurements that derive from the gou (or perhaps the other way around), such as the koku, which was considered the amount of rice that a single person would consume over the course of a year.

This is one of the human-centric forms of measurement that has survived the metric push; you can find various examples of this in many otherwise metric-converted countries. It turns out some studies show that those metrics often make certain categories of estimation easier for people.

Edited to cover the concern about matching the right amount of water:

It's worth noting that you don't need perfect precision for the amount of water, as long as you cook with the full cycle and not one of the express cooking modes. I can't remember the exact scientific principle behind it, but perhaps something to do with osmotic pressure. Some people use the remarkably effective method of measuring a certain amount of space between the dried rice and the water based on the size of their forefinger segment or thumbnail. It apparently works well for almost any imaginable size of pan (though you can have other problems with a pan too wide to have the rice cover the bottom). (Some types of rice do prefer more water than others, but within a single type, you have a fairly flexible range for the water ratio)