RPN vs Vibration Detection

On January 4, 1972, Hewlett-Packard announced the HP-35, world's first scientific calculator small enough to fit in a pocket - more precisely, Bill Hewlett's shirt-pocket. The HP-35 was an immediate hit with students, engineers, and scientists. Despite its steep price of $395 (about $3000 today), it sold ten times better than anticipated in the first year. Experience this unique calculator that won HP the prestigious "IEEE Milestone in Electrical Engineering and Computing" in 2009. Features: • Photo-realistic look-and-feel • Three skins: version 1, versions 2 & 3 (1973) and final version 4 (1974) • Vintage mode and Enhanced mode • Key-click and key-glow, both optional • Swipe left across display to correct number input errors • Cut/copy/paste display value • Display stack registers and memory registers • All decimal points but one light when iPhone battery charge drops below 5% Vintage mode In this mode, peculiarities of a real HP-35 are simulated: - original speed of operation - stack register Z copied to T on trig functions - leading zeros may be entered; zero can be made negative - a negative number may be entered by pressing CHS before or after the number - a keyboard entry or RCL immediately following STO does not raise the stack - for version 1 only: simulation of a number of known arithmetic bugs Enhanced mode - non-volatile stack and registers - use registers 1 through 9 with HP-45-like register arithmetic - register 0 works as LastX register

Solve your vibration problems of a car. The app can be used to analyze vibrations in a car. It can also be used to measure vibrations of systems. The app helps to locate if the vibration sources are the wheels or the cardan shaft. It is easy to setup. You can create a projects, specify the wheel size and gear ratio and start a measurement. Afterwards you get a chart of the measured vibrations. With the help of the project specific data and the speed the potential frequencies of tires ans gear shaft are calculated and displayed in the chart. The accelerometer of your device is used for the measurement. Currently a maximum of 50 Hz can be detected. Frequencies less than 5 Hz are visually filtered out. A fast Fourier transform (FFT) is used to find the frequency components of the vibrations. *** Features: - Create a project with car data - After a measurement you must specify the speed - The Result is displayed in a chart - The chart can be zoomed in and out - The chart displays a reference line when tapped to better identify the frequency - The chart displays potential sources of vibrations (wheels or cardan shaft) - Data can be exported: - A single measurement including the chart can be exported as pdf - The original data of a project can be exported and imported - With iTunes File Sharing or the Files app: all files can be accessed [date].fft - A simple analysis for vehicles is integrated - The analysis can be adapted to your needs with basis technical understanding. Use iTunes File Sharing to download a configuration file (It is named analysis-gui.json and should be self-explanatory). The accuracy depends on the accuracy of the build-in hardware. For a verifiable measurement result, please use a professional measuring device. The evaluation of the results must be done by a human. Vibrations are normla (i.e. for a car) and still exists if the car is working correctly.