# Time period for which the temperature A) has to be deviated B) has been deviated C) deviates

Let's assume that event Y occurs in a device if its temperature has deviated from its baseline for 10 or more seconds.

In other words, these 10 seconds represent a time period. And I would need to say:

This is the value of the time period for which the temperature ____ in order for Y to happen.
A) has to be deviated
B) has been deviated
C) deviates

I am not sure whether the perfect should be used or if choice A is OK.

• In future questions try to provide more context, this kind of writing needs context to be correct.
– Phil
Aug 12, 2014 at 17:29

I can't tell if the temperature change is good or bad. When you say a temperature deviates from the baseline that implies that the change is bad (maybe heating due to over current condition?). If the process and change is a good thing then use more positive words: exceed, surpass, or rise above all provide a positive view.

### Example of describing a bad condition

If the temperature deviates from the baseline for more than 10 seconds then the over current alarm will activate.

A sentence like this will warn the user of the result of the temperature change. There is a negative feeling associated with "deviates".

### Example of a good condition

After the temperature has exceeded the baseline for more than 10 seconds then the process will start.

You could use a sentence like this to describe a good result that the user is attempting to create.

### Some notes on your original sentence

First time periods cannot be described as having a value. Time periods have a duration. Actions resulting from a trigger condition being met are best described as occurring instead of happening.

Ten seconds is the duration of the time period for which the temperature must deviate in order for Y to occur.

This sentence is most like your original goal, but does not sound natural and I cannot find a good context it would fit in. It is quite understandable though.

After the temperature has deviated for ten seconds Y will occur.

This sentence would best fit into a description of steps in a process.

If the temperature deviates from baseline for more than ten seconds Y will occur.

This sentence puts the emphasis on informing the operator of what will happen if the temperature changes.

• Thanks, well, its neither a positive or a negative change, it is just something that happens. Anyway, it is a documentation and I would need to start like this: This variable holds a value of a duration for which .... Aug 12, 2014 at 17:46
• @Silkyss I've added some more details to better explain what would be needed by each option you provided and what they mean.
– Phil
Aug 12, 2014 at 17:46
• Thanks. Would this work? THis variable holds the duration of the time period for which the pH has to be deviated in order to activate the system. //I need to start the sentence exactly like this Aug 12, 2014 at 17:48
• Oh, it is a code comment or spec? If it is a comment in the code "duration of time in seconds before a pH deviation will activate the system." if it is documentation "The VAR_NAME variable holds the duration in seconds for which the pH must deviate in order to activate the system."
– Phil
Aug 12, 2014 at 17:50
• Since the code provides context, the comments need not provide the subject: the subject is the line of code after the comment.
– Phil
Aug 12, 2014 at 17:51