This lightweight hand-held instrument is an effective warning device for staff working in areas that can contain combustible gases.

这种轻型手持式测试仪对在可能存在易燃气体区域内工作的人员来说是有效的可燃气体警报装置。

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The air conditioning engineer can get the probes calibrated without having to send in the hand-held instrument (e. g. at Testo Industrial Services).

空调工程师可以得到，而无需在手持式仪器(如德图工业服务)发送校准探头。

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Using an instrument called a phoropter, an optometrist places a series of lenses in front of your eyes and measures how they focus light using a hand held lighted instrument called a retinoscope.

在使用综合验光仪时，验光师会将一套的镜片放在眼睛的前面，并通过一种名叫眼底镜的轻便简易的仪器测量出它们是如何聚焦光线的。

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