Moisture indicator  Manufacturers, Traders, Suppliers

Small, practical and inexpensive: The moisture indicators/humidity indicators consist of absorbent special paper, which is impregnated in some areas with variously concentrated cobalt II chloride solutions. The coloration from blue to violet to pink indicates the change in relative humidity in the environment. Depending on the model, the colouring changes in reverse order as soon as the air humidity decreases again (reversible indicators). Cobalt-free versions and irreversible moisture indicators are also available.

The deviations are about 2.5% relative humidity per 5°C above or below 20°C.

Export advice

When exporting to areas with extreme climatic conditions, it should be noted that - at temperatures above 20° C - the colour change occurs later - at temperatures below 20° C - earlier.

The humidity indicators are either inside the packaging or are part of viewing windows.
In properly prepared export packaging with desiccants, the relative humidity drops below 20% within a short time at normal temperatures. The humidity indicators used should therefore be blue in the 30 % display field. If this has not been done after 2-3 days, the packaging should be checked for leaks, insufficient quantities of desiccant or excessively moist packaged goods.
However, the color reaction of the moisture indicators may also be delayed, e.g. by excessively low temperatures in packaging in winter, inadequate air circulation between the moisture indicator and desiccant or unsuitable films.