[도와줘요 듀나인] 영어질문

When the Works arrive at the Participating Museum, they shall be stored in a place that is secure, locked,

and climate controlled to 70 Fahrenheit plus or minus 2 Fahrenheit and 50% relative humidity plus or minus 5%

 relative humidity, with fluctuations not to exceed more than 2 Fahrenheit or 5% respectively in a twenty-four hour period.

Deviations greater than the above in a twenty-four hour period must be reported immediately to the Chief Registrar.

짐작하시겠지만 계약서 같은 건데요.. 여기서 in 24 hour period가 무슨 뜻일까요..

24시간 안에만 변동이 있으면 안된다? 아니면 24시간 체제로 내내?? 자신이 없어요ㅠㅠ