How to solve the deviation of rated power of radiant tube

How to solve the rated power deviation of the radiant tube? Is there a good way? This is a problem we often encounter. In the production process of the radiant tube, the length of the alloy wire will affect the resistance of the alloy wire, which will affect the power of the radiant tube. The power error of the radiant tube exists. However, according to the "JB/T 2379-93 Industrial Radiant Tube Standard", the rated power deviation range of the radiant tube is as follows: Now I will give you a solution, basically these two. Under full heating conditions, the rated power deviation of the radiant tube should not exceed the following specified range: 1. If the rated power of the radiant tube is less than or equal to 100W: ±10%; 2. If the rated power of the radiant tube is greater than 100W: +5%~-10% or 10W, whichever is greater.