{"id":163,"date":"2015-09-28T08:17:50","date_gmt":"2015-09-28T08:17:50","guid":{"rendered":"http:\/\/www-test2.ssec.wisc.edu\/aeri\/?page_id=163"},"modified":"2021-07-28T06:05:59","modified_gmt":"2021-07-28T06:05:59","slug":"aeri-desiccant-replacement-procedure","status":"publish","type":"page","link":"https:\/\/www.ssec.wisc.edu\/aeri\/kb\/procedures\/maintenance\/aeri-desiccant-replacement-procedure\/","title":{"rendered":"AERI Desiccant Replacement Procedure"},"content":{"rendered":"<h3 class=\"p1\"><span class=\"s1\">Tools and Equipment Required<\/span><\/h3>\n<ul>\n<li class=\"p3\"><span class=\"s2\">Large flat head screwdriver<\/span><\/li>\n<li class=\"p3\"><span class=\"s2\">Desiccant:<span class=\"Apple-converted-space\">\u00a0 <\/span>approx. 5oz\/150 mL silica gel beads, molecular sieve, or calcium sulfate (Drierite).<span class=\"Apple-converted-space\">\u00a0 <\/span>Molecular sieve is recommended.<span class=\"Apple-converted-space\">\u00a0 <\/span>Alternatively the entire desiccator module (SPL6300G) can be replaced.<\/span><\/li>\n<li class=\"p3\"><span class=\"s2\">Recommended: Dry nitrogen gas, with 0-15 psi regulator, interferometer purge fitting, 0-10 scfh flow meter, and several feet of \u00bc&#8221; I.D. Tygon tubing.<\/span><\/li>\n<\/ul>\n<div style=\"background-color: #fcf8e3\">\n<h3 class=\"p1\"><span class=\"s1\">Precaution<\/span><\/h3>\n<ul>\n<li class=\"p3\"><span class=\"s2\">The interferometer in the extended range (ER) AERIs at the NSA and AMF-3 sites contains hygroscopic optics that will degrade upon exposure to humid air.<span class=\"Apple-converted-space\">\u00a0 <\/span>Use a dry nitrogen purge, if possible, to purge the interferometer case when performing a desiccant change.<span class=\"Apple-converted-space\">\u00a0 <\/span>Continue purging the case for several minutes after the desiccant assembly has been installed.<\/span><\/li>\n<li class=\"p3\"><span class=\"s2\">If purge gas is not available, minimize the time that the interferometer case is open to humid outside air by performing certain steps of the desiccant replacement procedure quickly.<\/span><\/li>\n<li class=\"p3\"><span class=\"s2\">Minimize the time that the replacement desiccant supply is open to outside air.<\/span><\/li>\n<\/ul>\n<\/div>\n<h3 class=\"p1\"><span class=\"s1\">Procedure<\/span><\/h3>\n<ol>\n<li class=\"p3\"><span class=\"s2\">Leave the spectrometer powered on during the desiccant replacement procedure.<span class=\"Apple-converted-space\">\u00a0 <\/span>This will keep the internal optics warm and gives added protection against humidity.<\/span><\/li>\n<li class=\"p3\"><span class=\"s2\">(Optional) Purge the interferometer case by connecting the purge gas source to the quick-release fitting on the back of the interferometer case.<span class=\"Apple-converted-space\">\u00a0 <\/span>A slow flow of ~5 scfh is appropriate.<\/span><\/li>\n<li class=\"p3\"><span class=\"s2\">Remove the desiccator module from the side of the interferometer case by unscrewing it counterclockwise (see Figs. 1, 2).<span class=\"Apple-converted-space\">\u00a0 <\/span>Use a flat head screwdriver to loosen it, if necessary.<\/span><\/li>\n<li class=\"p3\"><span class=\"s2\">Temporarily seal the circular opening on the interferometer case with tape or plastic.<\/span><\/li>\n<li class=\"p3\"><span class=\"s2\">Unscrew the metal cover of the porous polyethylene desiccator tube and remove the old desiccant (see Fig. 3).<span class=\"Apple-converted-space\">\u00a0 <\/span>The old desiccant may be regenerated or discarded.<\/span><\/li>\n<li class=\"p3\"><span class=\"s2\">Refill the tube with fresh desiccant and replace the cover.<\/span><\/li>\n<li class=\"p3\"><span class=\"s2\">Re-install the desiccator assembly.<span class=\"Apple-converted-space\">\u00a0 <\/span>Ensure that the o-ring is in its groove when mating the flange.<\/span><\/li>\n<li class=\"p3\"><span class=\"s2\">If the purge is being used, continue purging for 15 minutes at ~5 scfh, then disconnect the purge line.<\/span><\/li>\n<\/ol>\n<p class=\"p7\" style=\"text-align: center\"><a href=\"http:\/\/www.ssec.wisc.edu\/aeri\/wp-content\/uploads\/sites\/21\/2015\/09\/dessicator_module_location.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-167 size-full\" src=\"http:\/\/www.ssec.wisc.edu\/aeri\/wp-content\/uploads\/sites\/21\/2015\/09\/dessicator_module_location.png\" alt=\"dessicator_module_location\" width=\"483\" height=\"472\" srcset=\"https:\/\/www.ssec.wisc.edu\/aeri\/wp-content\/uploads\/sites\/21\/2015\/09\/dessicator_module_location.png 483w, https:\/\/www.ssec.wisc.edu\/aeri\/wp-content\/uploads\/sites\/21\/2015\/09\/dessicator_module_location-300x293.png 300w\" sizes=\"auto, (max-width: 483px) 100vw, 483px\" \/><\/a><\/p>\n<p class=\"p7\" style=\"text-align: center\"><span class=\"s2\">Figure 1.<span class=\"Apple-converted-space\">\u00a0 <\/span>Desiccator module location<\/span><\/p>\n<p class=\"p7\" style=\"text-align: center\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-166\" src=\"http:\/\/www.ssec.wisc.edu\/aeri\/wp-content\/uploads\/sites\/21\/2015\/09\/desiccator_module_removal-300x225.png\" alt=\"desiccator_module_removal\" width=\"483\" height=\"362\" srcset=\"https:\/\/www.ssec.wisc.edu\/aeri\/wp-content\/uploads\/sites\/21\/2015\/09\/desiccator_module_removal-300x225.png 300w, https:\/\/www.ssec.wisc.edu\/aeri\/wp-content\/uploads\/sites\/21\/2015\/09\/desiccator_module_removal.png 404w\" sizes=\"auto, (max-width: 483px) 100vw, 483px\" \/><\/p>\n<p class=\"p7\" style=\"text-align: center\"><span class=\"s2\">Figure 2.<span class=\"Apple-converted-space\">\u00a0 <\/span>Desiccator module removal \/ insertion<\/span><\/p>\n<p class=\"p7\" style=\"text-align: center\"><span class=\"s2\"><a href=\"http:\/\/www.ssec.wisc.edu\/aeri\/wp-content\/uploads\/sites\/21\/2015\/09\/desiccator_module_removal.png\"><br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-165\" src=\"http:\/\/www.ssec.wisc.edu\/aeri\/wp-content\/uploads\/sites\/21\/2015\/09\/desiccator_inside-300x225.jpg\" alt=\"desiccator_inside\" width=\"483\" height=\"362\" srcset=\"https:\/\/www.ssec.wisc.edu\/aeri\/wp-content\/uploads\/sites\/21\/2015\/09\/desiccator_inside-300x225.jpg 300w, https:\/\/www.ssec.wisc.edu\/aeri\/wp-content\/uploads\/sites\/21\/2015\/09\/desiccator_inside-768x576.jpg 768w, https:\/\/www.ssec.wisc.edu\/aeri\/wp-content\/uploads\/sites\/21\/2015\/09\/desiccator_inside-1024x768.jpg 1024w\" sizes=\"auto, (max-width: 483px) 100vw, 483px\" \/><\/a><\/span><\/p>\n<p class=\"p7\" style=\"text-align: center\"><span class=\"s2\">Figure 3.<span class=\"Apple-converted-space\">\u00a0 <\/span>Desiccant inside desiccator module<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Tools and Equipment Required Large flat head screwdriver Desiccant:\u00a0 approx. 5oz\/150 mL silica gel beads, molecular sieve, or calcium sulfate (Drierite).\u00a0 Molecular sieve is recommended.\u00a0 Alternatively the entire desiccator module (SPL6300G) can be replaced. Recommended: Dry nitrogen gas, with 0-15 psi regulator, interferometer purge fitting, 0-10 scfh flow meter, and several feet of \u00bc&#8221; I.D. [&hellip;]<\/p>\n","protected":false},"author":14,"featured_media":0,"parent":22,"menu_order":4110,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":""},"class_list":["post-163","page","type-page","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.ssec.wisc.edu\/aeri\/wp-json\/wp\/v2\/pages\/163","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ssec.wisc.edu\/aeri\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.ssec.wisc.edu\/aeri\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.ssec.wisc.edu\/aeri\/wp-json\/wp\/v2\/users\/14"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ssec.wisc.edu\/aeri\/wp-json\/wp\/v2\/comments?post=163"}],"version-history":[{"count":1,"href":"https:\/\/www.ssec.wisc.edu\/aeri\/wp-json\/wp\/v2\/pages\/163\/revisions"}],"predecessor-version":[{"id":2122,"href":"https:\/\/www.ssec.wisc.edu\/aeri\/wp-json\/wp\/v2\/pages\/163\/revisions\/2122"}],"up":[{"embeddable":true,"href":"https:\/\/www.ssec.wisc.edu\/aeri\/wp-json\/wp\/v2\/pages\/22"}],"wp:attachment":[{"href":"https:\/\/www.ssec.wisc.edu\/aeri\/wp-json\/wp\/v2\/media?parent=163"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}