Margin of error of timeing in power meter in the circumstance of teperature variation

[zzllearner]

In my power meter dedign,the accurancy of timing in the circumstance of high(70℃) or low（-40℃）temperature is
not very good, especially in low temperature(with the margin of error 9 ppm). except for software compensation. What can I do to improve the performance? Thank you for any help.

 

[crutschow]

Without seeing the design any suggestions are pure quesswork.