<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Very interesting idea! Thanks, Bob.<div class=""><br class=""><div><blockquote type="cite" class=""><div class="">On May 23, 2017, at 9:34 PM, <a href="mailto:bobkegel@comcast.net" class="">bobkegel@comcast.net</a> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="WordSection1" style="page: WordSection1; font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;"><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">Try a blank test on an impervious surface, such as a piece of glass. If you get the same high result, it would be from atmospheric moisture.</div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><o:p class=""> </o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">Bob K, neither chemist nor expert.</div></div></div></blockquote></div><br class=""></div></body></html>