Temperature coefficiant

#1

I tried compensated focus adjustments last night for the first time. I had entered 7 in the steps.deg field. When the temperature went down by one number the focus counts went up by 7 counts.

Why is that?

Ray

#2

Not really sure I understand the question…

From the manual:

Note: Negative temperature compensation ratios indicate that your focuser will move INWARD as temperature drops.

Since temperature drops are, by far the most commonly observed chage, we used this to standard user input on… If you enter “-7”, your focuser will move inward by 7 steps when temperature drops by seven degrees. Most people associate inward movement with smaller (or in this case negative numbers). Conversely, this same entry would result in outward movement of 7 steps if temperature increased by one degree.

#3

I , also, observed that as the temperature decreased the focuser had to move inward, i.e. the steps had to decrease. The slope of that line positive. If the focuser steps increased as temperature decreased then the slope of that line would be negative.

That is why I asked if there was a sign reversal going on.

Ray

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