***Not a teacher***
Your use of respectively is correct- nice work.
And in the second sentence, it should be "are compared," instead of "is compared," since the subject is the plural "substances." There might be some other more subtle problems with the sentence as well, but you'd probably have to ask a native speaker who knew what you were talking about. When you say "measured within," it implies precision, i.e. +/- 20-30 degC, whereas I think you mean "Since the process temperature of substance A is measured within the range of 20-30 degC." Check with an expert!
Student or Learner