一、前言Ⅲ型热电偶温度变送器(以下简称热偶温度)是DDZ一Ⅲ型仪表中的一个单元,它采用热电偶作为检测元件进行测温,广泛的应用于石油化工系统的检测和过程控制之中。热电偶的热电势与被测温度之间的关系有比较大的非线性,如铂铑一铂热电偶在 I. Preface Type III thermocouple temperature transmitter (hereinafter referred to as the thermocouple temperature) is a unit of DDZ-III instrument, which uses thermocouple as the measuring element for temperature measurement. It is widely used in the testing of petrochemical systems and Process control. The thermocouple thermoelectric potential and the relationship between the measured temperature is relatively large nonlinear, such as platinum and rhodium a thermocouple