Moisture indicator

• US 20030056710A1
• Filed: 09/04/2002
• Published: 03/27/2003
• Est. Priority Date: 09/15/2001
• Status: Abandoned Application

• Current Assignee: Machinery Nagel GmbH & Company
• Original Assignee: Machinery Nagel GmbH & Company
• Inventors: Moller, Klaus, Hoffman, Jurgen, Radmacher, Edmund
• Application Number:
  US10/233,479
• Publication Number:
  US 20030056710A1
• Time in Patent Office: Days
• US Class Current: 116/206
• CPC Class Codes: G01N 21/80 Indicating pH value
• CPC Class Codes: G01N 21/81 Indicating humidity
• CPC Class Codes: G01N 31/222 for investigating moisture content

Abstract

The moisture indicator has a support that is equipped with a substance which contains a moisture-indicating medium that reversibly changes color as a function of moisture. According to the present invention, the moisture-indicating medium is a pH indicator dye that is combined with a zinc salt.

Claims

1. A moisture indicator comprising a support that is equipped with a substance which contains a moisture-indicating medium that reversibly changes color as a function of moisture,

wherein the moisture-indicating medium is a pH indicator dye that is combined with a zinc salt.

2. The moisture indicator as defined in claim 1, wherein the indicator dye has a color change in the acid range.

3. The moisture indicator as defined in claim 1 or 2, wherein the indicator dye belongs to the group m-cresol purple, thymol blue, Tropaeolin 00, or p-xylenol blue.

4. The moisture indicator as defined in one of claims 1 through 3, wherein the zinc salt is zinc chloride, zinc nitrate, zinc sulfate, and/or zinc acetate.

5. The moisture indicator as defined in one of claims 1 through 4, wherein the indicator dye and zinc salt are present at a ratio by weight of at least 1:

5.

6. The moisture indicator as defined in claim 5, wherein the indicator dye and zinc salt are present at a ratio by weight of at least 1:

20.

7. The moisture indicator as defined in one of claims 1 through 6, wherein the support comprises an absorbent cellulose or an absorbent plastic, for example filter paper or nonwoven fabric, and/or an adsorbent, for example silica gel.