{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 2: MEASUREMENT ERRORS \n", "\n", "\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "##Example 2-1, Page Number: 16" ] }, { "cell_type": "code", "execution_count": 13, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Tolerance of the resistance= +/- 5 %\n", "Maximum Resistance at 75 degree celsius= 1.2915 kilo ohm\n" ] } ], "source": [ "#Variable Declaration\n", "\n", "#Resistance Values at 25 degree Celsius\n", "rmax25=1.26*10**3\n", "rmin25=1.14*10**3\n", "r=1.2*10**3\n", "ppm=500.0/1000000\n", "\n", "#Calculations\n", "\n", "absolute_error=rmax25-r\n", "\n", "#Tolerance value in percentage\n", "tolerance=absolute_error/r*100\n", "\n", "#Resistance per degree Celsius\n", "rperc=rmax25*ppm\n", "\n", "\n", "#To Calculate ressistance at 75 degree celsius\n", "\n", "dT=75-25\n", "\n", "dR=rperc*dT\n", "\n", "#Maximum resistance at 75 degree celsius\n", "\n", "rmax75=rmax25+dR\n", "\n", "\n", "#Results\n", "print 'Tolerance of the resistance= +/-',int(tolerance),'%'\n", "print 'Maximum Resistance at 75 degree celsius=',round(rmax75/1000,4),'kilo ohm'\n", "\n" ] }, { "cell_type": "markdown", "metadata": { "collapsed": true }, "source": [ "##Example 2-2, Page Number: 20\n" ] }, { "cell_type": "code", "execution_count": 12, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Maximum percentage error= 2.8 %\n", "V=( 180 V +/- 2.8 %)\n" ] } ], "source": [ "#Variable Declaration\n", "\n", "V1=100 \n", "V2=80\n", "p1=1.0/100 #Percentage error of V1\n", "p2=5.0/100 #Percentage error of V2\n", "\n", "\n", "#Calculations\n", "V1max=V1+V1*p1\n", "V2max=V2+V2*p2\n", "\n", "\n", "Emax=V1max+V2max\n", "E=V1+V2\n", "\n", "p=100*(Emax-E)/E\n", "\n", "#Results\n", "print 'Maximum percentage error=',round(p,1),'%'\n", "print 'V=(',E,'V +/-',round(p,1),'%)'\n", "\n", "\n", "\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "##Example 2-3, Page Number: 22" ] }, { "cell_type": "code", "execution_count": 5, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Maximum percentage error= +/- 25 %\n", "Voltage=( 20 V +/- 25 %)\n" ] } ], "source": [ "#Variable Declaration\n", "\n", "V1=100\n", "V2=80\n", "p1=1.0/100 #Percentage error of V1\n", "p2=5.0/100 #Percentage error of V2\n", "\n", "\n", "#Calculations\n", "E=V1-V2\n", "V1max=V1+V1*p1\n", "V2min=V2-V2*p2\n", "Emax=V1max-V2min\n", "\n", "p=100*(Emax-E)/E\n", "\n", "#Results\n", "print 'Maximum percentage error= +/-',int(p),'%'\n", "print 'Voltage=(',E,'V +/-',int(p), '%)'\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "##Example 2-4, Page Number: 23" ] }, { "cell_type": "code", "execution_count": 98, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Power= 82 mW\n", "Percentage error in power= +/- 20 %\n", "Power=( 82 mW +/- 20 %)\n" ] } ], "source": [ "#Variable Declaration\n", "r=820 #Resistance\n", "r_accuracy=10.0/100 #Accuracy of r in percentage\n", "I=10*10**(-3) #Current\n", "I_accuracy=2.0/100 #Accuracy of I at Full scale in percentage\n", "Imax=25*10**(-3) #Full scale current\n", "\n", "#Calculations\n", "power=r*(I**2)\n", "\n", "I_error=I_accuracy*Imax\n", "\n", "I_error_percentage=100*I_error/(10*10**(-3))\n", "\n", "Isquare_error=2*I_error_percentage\n", "\n", "p_error=Isquare_error+(r_accuracy*100)\n", "\n", "\n", "\n", "#Results\n", "print 'Power=',int(power*1000),' mW'\n", "print 'Percentage error in power= +/-',int(p_error), '%'\n", "print 'Power=(',int(power*1000),'mW +/-',int(p_error),'%)'\n", "\n", "\n", "\n", "\n", "\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "##Example 2-5, Page Number: 25" ] }, { "cell_type": "code", "execution_count": 6, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Average Deviation= 0.0012 volt\n" ] } ], "source": [ "import math\n", "\n", "#Variable Declaration\n", "V=[1.001,1.002,0.999,0.998,1.000] #Voltage readings\n", "v_average=0.0 #Variable to hold average value\n", "d=[0]*5 #Array of 5 elements to hold deviation\n", "D_average=0.0 #Variable to hold average deviation\n", "\n", "#Calculation\n", "for i in range(0,5):\n", " v_average=v_average+V[i]\n", " \n", "v_average=v_average/5.0\n", "\n", "for i in range(0,5):\n", " d[i]=V[i]-v_average\n", " \n", "for i in range(0,5):\n", " D_average=D_average+math.fabs(d[i])\n", "\n", "D_average=D_average/5\n", "\n", "print 'Average Deviation=',round(D_average,5),'volt'" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "##Example 2-6, Page Number: 26" ] }, { "cell_type": "code", "execution_count": 14, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Standard Deviation= 0.0014 V\n", "Probable Error= 0.94 mV\n" ] } ], "source": [ "import math\n", "\n", "#Variable Declaration\n", "\n", "V=[1.001,1.002,0.999,0.998,1.000] #Voltage readings\n", "v_average=0.0 #Variable to hold average value\n", "d=[0]*5 #Array of 5 elements to hold deviation\n", "D_average=0.0 #Variable to hold average deviation\n", "std_deviation=0.0\n", "\n", "#Calculation\n", "for i in range(0,5):\n", " v_average=v_average+V[i]\n", " \n", "v_average=v_average/5.0\n", "\n", "for i in range(0,5):\n", " d[i]=V[i]-v_average\n", " \n", "for i in range(0,5):\n", " std_deviation=std_deviation+d[i]**2\n", "\n", "std_deviation=math.sqrt(std_deviation/5)\n", "\n", "probable_error=0.6745*round(std_deviation,4)\n", "print 'Standard Deviation=',round(std_deviation,4),'V'\n", "print 'Probable Error=',round(probable_error*1000,2),'mV'" ] } ], "metadata": { "kernelspec": { "display_name": "Python 2", "language": "python", "name": "python2" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 2 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython2", "version": "2.7.9" } }, "nbformat": 4, "nbformat_minor": 0 }