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+--- Thread: (20S) and (21S) Intensity and Illumination (/thread-12998.html)
(20S) and (21S) Intensity and Illumination - Eddie W. Shore - 05-20-2019 12:48 PM
The follow equation relates the luminous intensity (measured in candelas, cd) and illuminance (measured in lux) of a light source. The equation assumes the light source radiates a spherical matter.
E = I / R^2
E = illuminance
I = luminous intensity
R = radius of the sphere's light (meters)
LBL A: Solve for E
LBL B: Solve for I
LBL C: Solve for R
Registers:
R0 = E
R1 = I
R2 = R
Store the following values in the register and execute the appropriate label.
Program:
Code:
01 LBL A: 61,41,A
02 RCL 1: 22, 1
03 ÷: 45
04 RCL 2: 22, 2
05 x^2: 51, 11
06 =: 74
07 STO 0: 21, 0
08 R/S: 26
09 LBL B: 61,41,B
10 RCL 0: 22,0
11 *: 55
12 RCL 2: 22,2
13 x^2: 51,11
14 =: 74
15 STO 1: 21, 1
16 R/S: 26
17 LBL C: 61,41,C
18 RCL 1: 22,1
19 ÷: 45
20 RCL 0: 22,0
21 =: 74
22 √: 11
23 STO 2: 21, 2
24 R/S: 26Example 1:
R1 = I = 400, R2 = R = 2.
Solve for E, XEQ A returns 100
Example 2:
R0 = E = 180, R2 = R = 3
Solve for I, XEQ B returns 1620
Example 3:
R1 = I =420, R0 = E = 195
Solve for R, XEQ C returns 1.467598771