Table restructuring for efficiency?
Only you can answer if the the change is worth the effort. 

Yes restructuring would be marginally more efficient. The main advantage being that new sensors can be added in the future without altering your table structure. The downside is that it's harder to enforce business rules and logic. 

The advantage of your current design is that if the sensor types are consistent per column you could have different data types, int, float, bit, varchar etc, whereas if you put all of your sensor values in a single column you'll need to use the lower common denominator (most likely a varchar). 

Given that you're talking about sensors, I expect you will be recording over time, so you'd probably need a timestamp, and decide on what else need to be stored with the value. Quality codes? non-detects? what about the sensor type?