https://www.vetnurse.co.uk/f/nonclinical-discussions/21080/refractometer-broken-can-i-borrow-your-manual Hi guys, I can&#39;t get any readings to show up on our refractometer at all, i.e., there is no colour change, and no line - this is when I have tried to callibrate with water. I have tried turning the two knobs at the top in both directions as far asen-USTelligent Community 10https://www.vetnurse.co.uk/thread/141404?ContentTypeID=1Thu, 04 Apr 2013 14:58:11 GMT1a0763ec-3885-442c-853e-6cef656dfec5:871a46b3-89d8-4d83-b653-13de92ad31aeSarah Cahill<p><a href="http://ucanr.org/sites/viticulture-fresno/files/115503.pdf">http://ucanr.org/sites/viticulture-fresno/files/115503.pdf</a></p><div style="clear:both;"></div>