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我厂由于生产工艺的变化,需将0～150℃温度范围扩展为0～300℃的范围。由于原用测温元件是铜电阻,配用XCZ-102型动圈显示仪表,分度号是G,要改成使用热电偶(EA-2)测温。修改后的测量线路图如图1所示。修改的方法如图2所示,在XCZ-102动圈显示仪表测量线路图中的a、b处断开,去掉并联电阻R_并,用一新的电阻R_串,代替原串联电阻R_串。R_串,阻值的大小,可先用电阻箱串接于电路中,再将热电偶(EA-2分度号)作为输入信号接入电路中,根据热电偶(EA-2分度号)的毫伏与温度关系对照表,确定温度上限量程300℃时的电阻值,即输入300℃时所对应的毫伏值22.90mV,不断调整电阻箱的阻值,当动圈表指针指到300℃时的电阻值,就是R_串的电阻值。然后用锰铜线
I plant due to changes in production technology, the need to 0 ~ 150 ℃ temperature range extended to 0 ~ 300 ℃ range. As the original temperature measuring element is a copper resistance, with XCZ-102-type moving coil display instrument, sub-degree number is G, to be changed to the use of thermocouple (EA-2) temperature. The revised measurement circuit shown in Figure 1. Modify the method shown in Figure 2, XCZ-102 dynamic display instrument measuring circuit diagram a, b at the disconnect, remove the parallel resistor R_ and, with a new resistor R_ string, instead of the original series resistance R _string. R_ string, the size of the resistance, resistance box can be connected in series with the circuit, then the thermocouple (EA-2 indexing number) as the input signal access circuit, according to the thermocouple (EA-2 index ) Millivolt and temperature control table to determine the upper limit of the temperature range 300 ℃ when the resistance value, that is, the input 300 ℃ corresponding to the millivolt value of 22.90mV, resistance box constantly adjusted, when the moving table pointer refers to 300 ℃ when the resistance is the resistance of R_ string. Then use manganese copper wire