Process Engineering Division – Instrumentation and Automation Section – Daily Topics – Topic No. 2020-12-30
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Process Engineering Division – Instrumentation and Automation Section – Daily Topics – Topic No. 2020-12-30: Discussion question: 342. Typically, the detection range of an H2S alarm is 0–100 PPM, with an output of 4–20 mA correspondingly. If the displayed value is 20 ppm, what is the output current? (5 points are given only to those who provide the correct answer; additional points are awarded for a correct calculation process or detailed explanation.)
20*16/100+4=7.2
4+(20-4)*20/(100-0)=7.2mA
4+(20-4)*20/(100-0)=7.2mA
20*16/100+4=7.2
4+(20-4)*20/(100-0)=7.2mA
20*16/100+4=7.2
20/100*16+4=7.2mA
I=20*16/100+4=7.2mA
Typically, the detection range of an H2S alarm is 0-100PPM, with an output of 4-20mA correspondingly. If the displayed value is 20 ppm, what is the output current? Solution: I = (20/(100-0)) * (20-4) + 4 = 7.2 (mA). Answer: If the displayed value is 20 ppm, then the output current is 7.2 mA.