4-20 Ma Formula: units = ( (Ma − 4 ) / 16) × ( Vmax − Vmin ) + Vmin
4-20 Ma Definition This 4-20 mA calculator is used to calculate the original measurement of overall vibration (or other physical pressure) units, as determined by the user or type of transducer, using the output current of the 4-20 mA transducer as well as the minimum and maximum of the unit range for the device. Check out the rest of our hundreds of calculators available for any type of calculations!
How this Calculator Works Transducers are used to convert a physical input into an analog electric signal. There are a wide variety of transducer types, including millivolt output transducers, voltage output transducers, and 4-20 mA output transducers. Of these options, a 4-20 mA signal is least likely to be affected by electrical resistance and noise in the transmission line. Because of that special property, 4-20 mA transducers are used when a signal must be transmitted a long distance through physical transmission lines. The elements involved in this calculator are the transducer input units, the unit range, and the output current of the transducer. Input units, in this case indicated by “V”, are units for measuring vibrations or some other sort of physical input. The output of the transducer is an electrical signal to be sent down a transmission line and is measured in milliamps. In the calculator, the following inputs are called for:
Field 1 (mA): Output current as measured in milliamps from the 4-20 mA transducer
Field 2 (Vmin): Minimum V, which is the bottom of the physical input range. This is in whatever units required by the calculation.
Field 3 (Vmax): Maximum V, which is the top of the physical input range.
While the variable “Vmin” and “Vmax” can of any type of unit of measure you wish, the unit types must be the same. If they are not, the result of the equation will be inaccurate.
The formula used is: Units = (Ma − 4 ) / 16) × ( Vmax − Vmin ) + Vmin
Interpreting the Results After correctly filling out and submitting the fields, the result given by the calculator is output in whatever units the “Vmin” and “Vmax” were input by the user. The values of Vmin and Vmax will normally be determined by the manufacturer of the transducer being used and can be found either in the manual for the device or on the manufacturer’s website. Helpful hints and tips:
Make sure the input for mA is in milliamps. Ensure it is not a decimal value of amps.
Always use the same unit of measure for Vmax as you used for Vmin.
Check with the manufacturer if you’re not sure of the Vmin and Vmax values for your transducer. Correct input of these values is necessary!
Vmin is usually zero (0). If the value you are inputting is something other than zero, double check to make sure you are putting in the right measurement.
How to Calculate 4-20 Ma Let's be honest - sometimes the best 4-20 ma calculator is the one that is easy to use and doesn't require us to even know what the 4-20 ma formula is in the first place! But if you want to know the exact formula for calculating 4-20 ma then please check out the "Formula" box above.