Moisture indicator
US5290516A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 22, 1992 |
| Grant date | Mar 1, 1994 |
| Priority date | — |
| Expiry date | Oct 22, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N31/222
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and product whereby color changing indicator salts such as cobaltous salts, preferably CoCl.sub.2 or CoBr.sub.2, are firmly adhered to sand, other particulate silicas or other carriers so that unwanted fines, material loss and solvent washing characteristic of prior indicator salt-coated carriers are eliminated. The process is carried out by thoroughly dehydrating a quantity of cobaltous salts and dissolving and storing the dehydrated cobaltous salt in absolute alcohol, preferably absolute ethanol. The absolute alcohol/cobaltous salt solution is then contacted onto a dehydrated or anhydrous carrier material and the absolute alcohol solvent is removed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.