The word ‘Normative’
1. There are other normative statements besides ethical ones: even aesthetic statements are normative (when you judge something to be ugly or beautiful) or statements about the presence of other values (say, ‘the meaning of life’ questions). I have never denied it. As you rightly point out, legal norms are normative but they are not co-extensive with the ethical ones.
2. If there are standards to measure some entity or phenomenon and that such measurements are not “necessarily normative”, of course, you are right. We can say whether a car has been properly assembled by referring to the standards of putting the parts of the car together; we can say that rice has been adulterated or even that storm has a strength measured by the Beaufort scale. None of these is normative. I am not claiming that ‘all’ measurements (or evaluations) are normative.
3. About the use of words. ‘Normative’ refers to judgments/sentences from natural languages that use norms. (In the case of ethics, which is what we discuss most often about, it refers to the ‘moral ought’; in case of law it is about the ‘legal ought’, in the case of aesthetics about the standard of aesthetic categories, and so on.) One distinguishes (in philosophy, for example) between ‘factual’ and ‘normative’ sentences, where statements from Natural Sciences (for instance) embody factual statements. Statements about ‘value’ (valuational or axiological statements in general) exhibit other properties than factual statements. There is no consensus about the nature of ‘values’: some believe that they express something typically human, some think that they exist in the world quite independent of human beings, speaking only about the two ends of the spectrum. Between these two ends, there are many possible permutations and combinations.
Normally, when I talk about the normative, I only have ethical judgments in mind.
There is a difference between evaluative statements and normative ones. Statements that ‘measure’ or ‘evaluate’ some or another phenomenon using a standard (even if it is a conventional standard) are evaluative in nature. Whether we speak about ‘winds attaining the force of X beaufort’ or about ‘the body temperature of a sick patient’ we are measuring phenomena. One could also evaluate the performance of a student in an examination or the share value of a corporation. These evaluations are not normative in nature. In other words, an evaluative statement is not necessarily normative in nature.