
to fix; to settle; to standardize; to regularize
constant; definite; uniform; defined; certain; prescribed
温度を一定にしないと実験の結果が変わってしまう。
If you don't keep the temperature constant, the experiment results will change.
温度を一定に保つことが実験の鍵だ。
Keeping the temperature constant is key to the experiment.
一定の条件を満たせば申請できます。
You can apply if you meet certain conditions.