Plus42 vs Signal Scaler

Plus42 is an advanced scientific programmable calculator, based on Free42. Free42, in turn, is a complete re-implementation of the HP-42S scientific programmable RPN calculator, which was made from 1988 until 1995 by Hewlett-Packard. Free42 is a complete rewrite and contains no HP code whatsoever. Plus42 builds on Free42 and adds: Algebraic expressions modeled after those used on the HP-27S and HP-17B/19B; attached units and unit conversions modeled after those used on the HP-48/49/50 series; directories for more organized storage of programs and variables; a larger display, with 8 rows and 22 columns (131x64 pixels) by default, which the user may resize at will; time value of money and amortization schedules; and two-dimensional plotting of functions, with ability to zoom and pan, and find integrals and roots from points in the plot.

Signal Scaler is a fast, straightforward calculator for instrumentation technicians, controls professionals, electricians, and engineers working with 4–20 mA signals. Quickly convert between: • 4–20 mA signal values • Percentage of calibrated range • User-defined engineering units • Differential-pressure percentage • Square-root flow percentage Enter the transmitter’s lower and upper range values, then calculate the corresponding current, percentage, or engineering-unit value. Features include: • Linear 4–20 mA scaling • Differential-pressure-to-flow square-root calculations • Adjustable LRV and URV • User-defined engineering units • Quick selection of common 8, 12, and 16 mA values • Automatic limits for valid signal and percentage ranges • Simple interface designed for field use • No account required • Works offline Signal Scaler is intended as a convenient calculation aid. Always verify critical values using approved procedures and calibrated test equipment.