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--- slope_intercept [2026/05/22 21:10] – created reno
+++ slope_intercept [2026/05/25 15:05] (current) – reno
@@ Line 2: / Line 2: @@
 The Slope and Intercept values describe a relation of the bottom micrometer step movement to the top micrometer step movement. The top micrometer movement per wavelength is determined by the dispersion file in use by the instrument.
-Note: This standard operating procedure (SOP) is based on using Brewer Test Plots program (GA tab) to process a series of GA files, complete with the dispersion in use to collect an average Slope and intercept value.  Only if the Slope or intercept value has changed significantly is any change applied. Brewer Test Plots is a software created by International Ozone Services (IOS) Inc.
 ===== Collecting Data to Determine Slope and Intercept =====
@@ Line 9: / Line 9: @@
 ====== Processing the GA ======
+Note: This standard operating procedure (SOP) is based on using Brewer Test Plots program (GA tab) to process a series of GA files, complete with the dispersion in use to collect an average Slope and intercept value.  Only if the Slope or intercept value has changed significantly is any change applied. Brewer Test Plots is a software created by International Ozone Services (IOS) Inc.
   - Open Brewer Test Plots and select the GA tab and check slits 1 and 5 and select a 7-position fitting. {{ :pictures:software:brewer_test_plot_ga_tab.png?400 |}}
   - Select the dispersion in use while the GA measurement were taken for the instrument you are interested in. **Note:** do not use the cubic version of the dispersion file. {{ :pictures:software:brewer_test_plot_ga_dcf.png?400 |}}
@@ Line 17: / Line 18: @@
   - The circled GS/GI value circled are the values we are interested in. Since these scans will not provide an identical response every time multiple file should be process.
   - Record the GA result in a table and step 1 with a new GA file until you have a few GA processed.
 |   |File Name|Slope|Intercept|Maximum estimated % loss in counts over measurement range|
 |Original values|   |0.99730|-3.50|1.89|
 |   |
 |New Values|GA11426.190|1.0031|-15.27|0.3|
-|   |GA11626.190|0.999974|-11.29|0.6|
+|   |GA11626.190|0.99974|-11.29|0.6|
 |   |GA11826.190|1.00000|-14.84|0.30|
 |   |GA11926.190|1.0033|-14.70|0.5|
+|   |
+|Mean Value|   |1.001535|-14.025|0.425|
+|% diff from previous|0.3%|282%|1.37%|
+===== Docs =====
+{{ :docs:slope_and_intercept_determination.pdf |ECCC Slope and Intercept SOP}}