What is the difference between the range corresponding to 4-20mA output of the instrument and the instrument’s own range?
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What is the difference between the range corresponding to 4-20mA output of the instrument and the instrument’s own range?
The range corresponding to 4-20mA output by the instrument refers to the minimum and maximum values of the measured parameter that 4mA and 20mA represent respectively when the instrument outputs a signal. The range of the instrument itself refers to the range from the minimum to the maximum value that the instrument can measure. The two are usually corresponding, but sometimes due to calibration, configuration, or functional limitations, the 4-20mA range output by the instrument may be set within a sub-range of the instrument’s overall range. .
1. The range from the minimum to the maximum value of the variable being measured is called the measurement range； 2. A measuring instrument has a minimum value and a maximum value that it can measure; this range is known as the instrument’s measurement range ； 3. The range from the minimum to the maximum scale of a measuring instrument is called the range of that instrument. When selecting a measuring instrument, it is necessary to choose one whose range is greater than the maximum possible value of the variable being measured and as close as possible to that maximum value. Due to changes in the production process, the range of the instrument can be adjusted according to the actual range of the variable being measured.
It seems it doesn’t matter; it’s just a protocol for output current, and the association recommends 20mA