Process Engineering Division – Instrumentation and Automation Section – Daily Topics – Topic No. 2020-12-06
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Process Engineering Division – Instrumentation and Automation Section – Daily Topics – Topic No. 2020-12-06: Discussion topic: 318. When someone was calibrating the 1151AP absolute pressure transmitter, it was found that as long as power was supplied to it, the instrument would output 12 mA. Please calculate and explain whether this phenomenon is normal (If the gauge’s measurement range is 50–150 KPa absolute pressure, and the atmospheric pressure at that time is 100 KPa.) (5 points will be given to those who provide the correct answer; additional points will be awarded for a correct calculation process or detailed explanation.)
It is normal, as the absolute pressure transmitter measures absolute pressure. The measurement range of this instrument is 50–150 Kpa; in other words, when an absolute pressure of 50 Kpa is applied, the instrument outputs 4 mA； When an absolute pressure of 150 KPa is applied, the instrument outputs 20mA ； At atmospheric pressure, that is, when an input pressure of 100 Kpa is applied, the instrument’s output is 16 × % + 4 = 12 mA. Since the instrument’s output is exactly 12 mA, it is functioning normally
When someone was calibrating the 1151AP absolute pressure transmitter, they found that as long as power was supplied, the instrument would output 12mA. (This phenomenon is normal if the gauge’s measurement range is 50–150 KPa gauge pressure, and the atmospheric pressure at that time is 100 KPa.) Since the absolute pressure transmitter measures absolute pressure, its measurement range is 50–150 Kpa; in other words, when an absolute pressure of 50 Kpa is applied, the transmitter outputs 4 mA ； When an absolute pressure of 150 KPa is applied, the instrument outputs 20mA ； At atmospheric pressure, that is, when an input pressure of 100 Kpa is applied, the instrument’s output is ×(100-50)+4 = 12mA. Since the instrument’s output is exactly 12mA, it is functioning normally.
The absolute pressure transmitter operates in the range of 50 kPa to 150 kPa; at an atmospheric pressure of 100 kPa, the transmitter outputs 12 mA. Normal
This phenomenon is normal. The absolute pressure transmitter measures absolute pressure, and its measurement range is 50–150 Kpa; in other words, when an absolute pressure of 50 Kpa is applied, the transmitter outputs 4 mA ； When an absolute pressure of 150 KPa is applied, the instrument outputs 20mA ； At atmospheric pressure, that is, when an input pressure of 100 Kpa is applied, the instrument’s output is 16 × % + 4 = 12 mA. Since the instrument’s output is exactly 12 mA, it is functioning normally
The absolute pressure transmitter operates in the range of 50 kPa to 150 kPa; at an atmospheric pressure of 100 kPa, the transmitter outputs 12 mA. Normal
Normal: atmospheric pressure is 100 KPa. (100-50)/(150-50) = 50%; 50%*16+4 = 12 mA
An output of 12mA is normal; 16 ×% + 4 = 12mA.
Normal. It is the value corresponding to atmospheric pressure.
The calibration environment is at atmospheric pressure; since it is an absolute pressure transmitter, an output of 12mA is correct