StrayLightP - Stray light curve correction

Description

J E Patterson - jepspectro.com - version 20150902

Spectrophotometers have some stray light or detector dark current which causes the calibration to be non linear at high absorbances. Absorbance = Log (Incident light Intensity)/(Transmitted light Intensity).

This program corrects for the calibration curvature caused by the presence of stray light.

Enter f USER to avoid the f key during data input.

Input two standard concentration values y1 ENTER y2 f A.
Input two corresponding absorbances x1 ENTER x2 f B.
The % stray light is displayed. This is stored in register 8.

Input an unknown sample absorbance x f D the resulting concentration y is displayed and stored in register .4
Input a concentration y f C. Solve is used to obtain an absorbance x.

Sample data: [x,y] [1,1 2,1.7].
% stray light is 1.23%

Program Resources

Labels

Name Description
A y1 Enter x2 A
B x1 Enter y2 B
C Enter concentration y A to get absorbance x
D Enter absorbance x A to get concentration y
1 Start of loop
5 StrayLight function-y=0 for Solve

Storage Registers

Name Description Name Description
1 y1 concentration of standard 1 11 x1 absorbance of standard 1
2 y2 concentration of standard 2 12 x2 absorbance of standard 2
4 Stray light fraction 13 x absorbance
5 Stray light old 14 y concentration
6 Temp 1 19 y f C. Solve is used to get x
7 Temp 2 I Loop counter register, decrement 20 to 0.
8 % stray light

Program

Line Display Key Sequence
000   
001 42;21;11 f LBL A
002 44 2   STO 2
003 33   R↓
004 44 1   STO 1
005 43 32 g RTN
006 42;21;12 f LBL B
007 44 .2   STO . 2
008 33   R↓
009 44 .1   STO . 1
010 2   2
011 0   0
012 44 25   STO I
013 0   0
014 44 4   STO 4
015 42;21; 1 f LBL 1
016 45 4   RCL 4
017 44 5   STO 5
018 45 .1   RCL . 1
019 1   1
020 45 .1   RCL . 1
021 13   10^x
022 30   -
023 45 5   RCL 5
024 20   ×
025 1   1
026 40   +
027 43 13   g LOG
028 30   -
029 44 6   STO 6
030 45 2   RCL 2
031 45 1   RCL 1
032 10   ÷
033 20   ×
034 44 7   STO 7
035 45 .2   RCL . 2
036 45 7   RCL 7
037 30   -
038 13   10^x
039 1   1
040 30   -
041 1   1
042 36   ENTER
043 45 .2   RCL . 2
044 13   10^x
045 30   -
046 10   ÷
047 44 4   STO 4
048 42; 5;25   f DSE I
049 22 1   GTO 1
050 45 4   RCL 4
051 26   EEX
052 2   2
053 20   ×
054 44 8   STO 8
055 43 32 g RTN
056 42;21;14 f LBL D
057 44 .3   STO . 3
058 1   1
059 45 .3   RCL . 3
060 13   10^x
061 30   -
062 45 4   RCL 4
063 20   ×
064 1   1
065 40   +
066 43 13   g LOG
067 30   -
068 45 6   RCL 6
069 10   ÷
070 44 .4   STO . 4
071 43 32 g RTN
072 42;21;13 f LBL C
073 44 .9   STO . 9
074 48   .
075 9   9
076 20   ×
077 36   ENTER
078 42;10; 5   f SOLVE 5
079 43 32 g RTN
080 42;21; 5 f LBL 5
081 32 14   GSB D
082 45;30; .9   RCL - . 9
083 43 32 g RTN