Which article is aloud to be used with the term "launch power"?

Question

I'm having problem with the usage of articles for the word "power", namely "launch power" (the power at the input of a glass fiber):

"power" is uncountable in this case:

Power" can also mean physical force or energy, like electricity. This meaning is uncountable.see English Club

Now I wish to use it in sentences in my thesis, for instance:

Table 5.5 shows the magnitude of the first five coefficients given a launch power of −10, 0, and +10 dBm in the case of transmission over 100 km.

If power is uncountable, I should not be using the article "a". However, using no article makes the sentence sound strange and probably also wrong:

Table 5.5 shows the magnitude of the first five coefficients given launch power of −10, 0, and +10 dBm in the case of transmission over 100 km.

Would the definite article "the" be the proper solution here (even though I think it is not the right determiner in this case...)?

I have searched in the internet and found some sources regarding countable and uncountable nouns. Non of them seem to tackle my problem. I hope someone has a good answer for this problem, and maybe also a general rule about similar cases.

Answer 1

Your example contains a countable sense of "power". The word "power" here does mean something like magnitude of force or how quickly the energy to do work is delivered, and that particular meaning usually has an uncountable sense.

The structure of your sentence changes that. You're not talking about power in the abstract. You're not talking about that property as a thing separate from its value. Instead, you're listing a few possible values for that property.

One thing about your sentence confuses me. I'm not sure whether I'm counting to one or to three. You may want to consider these options:

given a launch power of -10, 0, or +10 dBm
given launch powers of -10, 0, and +10 dBm

The conjunction "or" suggests that we consider each power one at a time, making the countably singular form appropriate. The "and" suggests that we consider them together, making the plural a sensible choice.