| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To satisfy explosion-proof structure requirements while keeping a consumption current small by enabling a photocoupler of a small package of a relatively short inner filler space distance to be used. <P>SOLUTION: While a flowmeter is installed in a hazardous area, a measuring instrument such as an integrator is installed in an unclassified area. A safety holder is inserted between them, and transmission of energy from an unclassified area side to a dangerous area side is limited to a safe value even in case of accident. The signal line of the flowmeter is connected to the measuring instrument via an insulated separation circuit, and furthermore via the safety holder. In this case, for intrinsically safe explosion proof, photocouplers PC1, PC2 of two-step constitution are inserted for separating an inner inductance and a capacitance of the flowmeter to become a negligible value viewed from a safety holder side. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
