1 files changed, 54 insertions, 0 deletions
diff --git a/174/CH4/EX4.7/example4_7.sce b/174/CH4/EX4.7/example4_7.sce
new file mode 100755
index 000000000..238f8f6f7
--- /dev/null
+++ b/174/CH4/EX4.7/example4_7.sce
@@ -0,0 +1,54 @@
+// To find the scale error
+// Modern Electronic Instrumentation And Measurement Techniques
+// By Albert D. Helfrick, William D. Cooper
+// First Edition Second Impression, 2009
+// Dorling Kindersly Pvt. Ltd. India
+// Example 4-7 in Page 67
+
+
+clear; clc; close;
+
+// Given data
+R_h = 2000; //The desired scale marking for the half scale deflection
+E = 3; //The internal battery voltage in volt
+I_fsd = 1 *(10^-3); //Current for full scale deflection in ampere
+R_m = 50; //resistance of the basic movement in ohm
+
+//Calculations
+I_t = E / R_h; //Total battery current at FSD
+I_2 = I_t - I_fsd; // Current through zero-adjust resistor R_2
+R_2 = I_fsd * R_m/I_2;
+R_p = R_2*R_m/(R_2 + R_m);
+R_1 = R_h - R_p;
+printf("(a)  The value of R_1 and R_2 is")
+printf("The value of zero-adjust resistor R2 =%0.1f ohm\n",R_2);
+printf("The value of current-limiting resistor R1 =%0.1f ohm\n",R_1);
+
+//At a 10% drop in battery voltage
+E = 3- 0.3;
+I_t = E / R_h; //Total battery current in A
+I_2 = I_t - I_fsd; //Shunt current in A
+R_2 = ceil(I_fsd * R_m/I_2);
+R_p = R_2 *R_m/(R_2+R_m);
+R_h = R_1 + R_p;
+%error = (2000-2003.7)/2003.7*100;
+printf("\n(b)  The maximum value of R2 to compensate the drop in battery voltage = %d ohm\n",R_2);
+printf("The true value of the half-scale mark on the meter is = %0.3f ohm\n",R_h);
+printf("\n(c)  The percentage error = %0.3f%%\n",%error);
+disp('The negative sign indicates that the meter reading is low');
+
+//Result
+// (a)  The value of R_1 and R_2 isThe value of zero-adjust resistor R2 =100.0 ohm
+// The value of current-limiting resistor R1 =1966.7 ohm
+
+// (b)  The maximum value of R2 to compensate the drop in battery voltage = 143 ohm
+// The true value of the half-scale mark on the meter is = 2003.713 ohm
+
+// (c)  The percentage error = -0.185%
+ 
+// The negative sign indicates that the meter reading is low    
+
+
+
+
+