{"id":17520,"date":"2023-06-08T10:41:10","date_gmt":"2023-06-08T17:41:10","guid":{"rendered":"https:\/\/www.vernier.com\/til\/?p=17520"},"modified":"2025-04-25T15:32:39","modified_gmt":"2025-04-25T22:32:39","slug":"how-do-i-apply-a-correction-factor-for-vernier-par-sensors","status":"publish","type":"post","link":"https:\/\/www.vernier.com\/til\/17520","title":{"rendered":"How do I apply a Correction Factor to Vernier PAR sensors?"},"content":{"rendered":"

For information on correction factor values, see<\/strong> Can I use Vernier PAR sensors with electric lights? When do I need to use a Correction Factor?<\/a><\/p>\n

You may need to apply a PAR sensor correction factor if you are measuring PAR underwater, in certain filed conditions, or when using LED-based light sources. A correction factor is a multiplication factor applied to a PAR sensor’s Photosynthetic Photon Flux Density (PPFD) readings that adjusts for spectral errors from the sensor or the conditions. Simply multiply the sensor reading by the correction factor to get a more accurate measurement of PAR. This can be done in the data collection software.<\/p>\n

<\/div>\n

For Go Direct PAR (GDX-PAR<\/a>)<\/h3>\n

GRAPHICAL ANALYSIS or LABQUEST APP<\/strong><\/h4>\n
    \n
  1. Launch the data collection app (Graphical Analysis or LabQuest App) and connect your Go Direct Par sensor.<\/li>\n
  2. Activate the PPFD-CF sensor channel. For specific instructions on how to do that, see How do I turn on other sensor channels for Go Direct Sensors?<\/a>.<\/li>\n
  3. Click or tap the meter for this channel, choose calibrate, and enter the correction factor for your condition. <\/li>\n
  4. Click or tap Keep to apply the correction factor, then click or tap Done. <\/li>\n
  5. This channel will now report the corrected PAR value using the applied correction factor.<\/li>\n<\/ol>\n
    <\/div>\n

    For PAR Sensor (PAR-BTA<\/a>)<\/h3>\n

    GRAPHICAL ANALYSIS APP<\/strong><\/h4>\n
      \n
    1. Launch Graphical Analysis app, select Sensor Data Collection, then connect the sensor to your device. <\/li>\n
    2. If running the progressive web app, connect the sensor to Graphical Analysis (see How do I connect USB sensors to the Progressive Web App version of Graphical Analysis (and other Vernier apps)?<\/a>).<\/li>\n
    3. Click or tap View Options, \"\" , and select to show the Data Table.<\/li>\n
    4. Click or tap Column Options, \"\", next to the PPFD column heading, then choose Add Calculated Column. <\/li>\n
    5. Name the Column PPFD-CF and use the same units used for the PPFD column (\u03bcmol\u2219m\u207b\u00b2\u2219s\u207b\u00b9). <\/li>\n
    6. Select Insert Expression and choose A*X+B. <\/li>\n
    7. Enter the correction factor for your condition as Parameter A. <\/li>\n
    8. Verify that Column X is the PPFD column, and set Parameter B to zero. <\/li>\n
    9. Select Apply. This will create a calculated column that displays the corrected PPFD. <\/li>\n
    10. Click or tap the Y-axis label to display the PPFD and\/or the PPFD-CF readings.<\/li>\n
    11. Optional:<\/em> Show a meter for the PPFD-CF column. (Graphical Analysis Pro only)\n
        \n
      1. Click or tap on View Options, \"\", and select Meters. <\/li>\n
      2. Click or tap Meter All Columns, \"\", in the top right corner of the PPFD meter.<\/li>\n
      3. Select Add \/ Remove Meter and select to show the PPFD-CF. This meter will display the corrected PPFD readings.<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n
        <\/div>\n

        LABQUEST APP<\/strong><\/h4>\n
          \n
        1. Connect the PAR sensor to your LabQuest. <\/li>\n
        2. Tap the Table tab to display the data table. <\/li>\n
        3. Choose New Calculated Column from the Table menu. <\/li>\n
        4. Enter the Name PPFD-CF and enter the proper units for PPFD (\u03bcmol\u2219m\u207b\u00b2\u2219s\u207b\u00b9). <\/li>\n
        5. Select AX from the Equation Type drop down menu. <\/li>\n
        6. Select PPFD as the Column for X, and enter your correction factor as the value for A. <\/li>\n
        7. Select OK. A graph of PPFD-CF vs<\/em>. time will be displayed. A live read out of the corrected PPFD will be displayed next to the graph.<\/li>\n
        8. Optional: <\/em>Show a graph of both PPFD and PPFD-CF columns.\n
            \n
          1. Tap on the Graph drop down menu. <\/li>\n
          2. Select Show Graph and then select All Graphs. Two graphs, the corrected PPFD reading (PPFD-CF) and PPFD reading without a correction, are displayed.<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n
            <\/div>\n

            LOGGER PRO<\/em><\/strong><\/h4>\n
              \n
            1. Choose New Calculated Column from the Data menu. <\/li>\n
            2. Enter PPFD-CF as the Name and and enter the proper units for PPFD (\u03bcmol\u2219m\u207b\u00b2\u2219s\u207b\u00b9). <\/li>\n
            3. Enter the correction factor for your condition under Expression followed by an asterisk (*) and then select PPFD under the Variables (Columns) drop down menu. (e.g., 1.15*”PPFD”)<\/li>\n
            4. Click Done. <\/li>\n
            5. Click or tap the Y-axis label and select to display the PPFD and\/or the PPFD-CF columns.<\/li>\n
            6. Optional: <\/em>Add a digital meter for the PPFD-CF column.\n
                \n
              1. Select Meter from the Insert menu. <\/li>\n
              2. Select Digital Meter. A meter displaying the corrected PPFD values should be displayed. <\/li>\n
              3. Select Auto Arrange from the Page Menu. This will place the PPFD-CF meter directly below the original PPFD meter.<\/li>\n<\/ol>\n<\/li>\n<\/ol>","protected":false},"excerpt":{"rendered":"

                For information on correction factor values, see You may need to apply a PAR sensor correction factor if you are measuring PAR underwater, in certain…<\/p>\n","protected":false},"author":8971,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[],"tags":[7666,1487,3071],"class_list":["post-17520","post","type-post","status-publish","format-standard","hentry","tag-gdx-par","tag-par","tag-par-bta"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/posts\/17520","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/users\/8971"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/comments?post=17520"}],"version-history":[{"count":0,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/posts\/17520\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/media?parent=17520"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/categories?post=17520"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/tags?post=17520"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}