Regarding product purity: translation of ppm levels
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The product is processed to have impurity levels of just a few parts per million. Literally translated, there is no problem, but when considering the manufacturing process, it isn’t quite appropriate. A few parts per million – the number should be less than 10; it seems reasonable to assume that impurities should be below 10PPM. However, the actual levels of impurities are as follows: Impurity A: 20ppm, Impurity B: 1000ppm, Impurity C: 3000ppm. Does anyone have a better way to phrase this? This post was last edited by ludinggi on 2009-3-14 21:27]
The product is processed to have such low levels of impurities that they can be expressed in ppm.
The content of impurity C after treatment is 3000 ppm, which means three thousandths; such a ratio is acceptable! The translation by moderator Lu Dingji should be fine!
The product is processed so that it contains impurities in the ppm range; the level of impurities is kept at the ppm level, which means there’s no need to specify it as a fraction of a million. It’s usually below 10 ppm. The translator’s translation is fine: Impurity A: 20 ppm, Impurity B: 1000 ppm, Impurity C: 3000 ppm. If these are indeed the actual levels of impurities present, then there must be an issue with the instructions – the levels for B and C are too high, which is contradictory. If the actual levels are that high, then the product is not of satisfactory quality
The ppm level is on the ppm scale, but I’ve never seen it reach 3000 ppm
Obviously there’s a problem; it’s contradictory
This is a sentence from the process training manual; it means that there are very few impurities, though it may not be expressed exactly. Let’s still use the translation “ppm level”!
The product is processed to contain only ppm levels of impurities. After processing, the product’s impurity content is at the ppm level. In practical use, the value of 3000 ppm is also mentioned; ppm is an abbreviation for part per million, which means … per million. 1 PPM corresponds to one in a million. PM is a unit of ratio, with 1% representing one in 100. The original poster didn’t understand what ppm means; it’s not true that only values below 10 ppm can be expressed in ppm. Just like %, ppm can be followed by any number.
It's better to use ppm levels. The ability to achieve ppm-level precision in process operations does not mean that all operations can reach this level; it depends greatly on the actual operating conditions.
Quality indicators are no trivial matter at all. By ppm levels, we mean values below 10 ppm; levels in the tens are still acceptable, but those in the hundreds are unacceptable. Therefore, one cannot just state whatever level one wants – it might be 3000 ppm today and 30000 ppm tomorrow. Even if someone uses such figures or writes them down, one should not follow suit; any incorrect or problematic values must be removed
PPM is better; both Europe and the United States use this
The impurity content is on the ppm level; it’s not necessarily a few parts per million