1)Let the instrument switch on for 1 hour before analysis.
2)On the instrument for 1 hour before analysis.
3)Switch on the instrument and leave it on for 1 hour before analysis.
4)Switch on the instrument and conduct the analysis after 1 hour.
5)Turn on the instrument and allow a 1 hour warm-up period before analysis.
Which sentence(s) is/are acceptable?
3, 4, and 5 are acceptable.
Yes,; but, I don't much like "conducting" an analysis.
All of the sentences are acceptable, but some may be more clear or explicit than others.
1) "Let the instrument switch on for 1 hour before analysis." This sentence is acceptable because it conveys the idea that the instrument should be switched on and allowed to run for an hour before conducting the analysis.
2) "On the instrument for 1 hour before analysis." This sentence is not grammatically correct, and it is unclear what it is trying to convey. It should be rewritten to be more specific and clear.
3) "Switch on the instrument and leave it on for 1 hour before analysis." This sentence is also acceptable because it clearly instructs to switch on the instrument and keep it running for an hour before conducting the analysis.
4) "Switch on the instrument and conduct the analysis after 1 hour." This sentence is acceptable, but it may be slightly more ambiguous compared to the other sentences. It could, for example, be interpreted as immediately conducting the analysis after switching on the instrument rather than waiting for a full hour.
5) "Turn on the instrument and allow a 1 hour warm-up period before analysis." This sentence is also acceptable because it clearly states to turn on the instrument and give it a specifically designated warm-up period of 1 hour before conducting the analysis.