The meter is devided into two parts: the primary meter (detector) and the secondary meter.

该仪器分为一次表（探头）和二次表两部分。

youdao

The working principle of the vibration-type water mud densimeter is dis-cussed in our paper. It guided the design of the variator and the secondary meter.

本文分析了振动式水泥浆密度计的原理，指导了变送器和二次仪表的设计。

youdao

It is very convenient for the field operators and can be used as a secondary meter in mining industry, the petroleum chemical industry, the metallurgical industry.

该仪器体积小、功能强、精度高，可以广泛适用于电力系统及相关行业继电保护和计量专业、工矿企业、石油化工、冶金企业的二次回路检查。

youdao

Both the drywell and the wetwell are surrounded by a secondary containment vessel (or shield building) also built from reinforced concrete about a meter thick.

FORBES: Explainer: What Caused The Incident At Fukushima-Daiichi