没有安全门定期校验及试验记录。

No periodic verification and test record on safety valves.

youdao

因此，必须对仪器和设备定期校验，才能提供可靠的发热量数据。

So must regularly verify instruments and equipments to provide reliable caloric data.

youdao

对补偿系统的定期校验则可以弥补机床磨损造成的精度降低，使线切割机床的高精度工作寿命得到延长。

Periodical check on the compensation system can make up the degraded precision due to the machine's wearing, and prolong the work life of the line cutting machine tools.

youdao