Humidity indicators – for reliable control
Small, practical and cost-effective: The moisture indicators are made from special absorbent paper, certain parts of which are impregnated with cobalt (II)-chloride solutions of varying concentrations. The colouring from blue to purple to pink shows the change in relative humidity in the ambient air. Depending on the indicator’s design, the colours can change in reverse sequence once the air humidity decreases (reversible indicators). Cobalt-free and irreversible humidity indicators are also available.
Indicator accuracy
The humidity indicators are small, simply designed, and inexpensive, so you cannot compare their measurement accuracy with that of expensive electronic instruments. At a test temperature of 20°C (+/– 2°C), the permitted tolerance is +/– 5% relative humidity.
This means the indicators are compliant with the German Federal Armed Forces technical delivery conditions (“Technische Lieferbedingungen”) TL 6685-0003, version 6 (September 2018).
The deviations are approximately 2.5% relative humidity per 5°C above and below 20°C.
Export information
When exporting goods to destinations with extreme climates, please note that the colour changes later in temperatures above 20°C, and earlier in temperatures below 20°C.
Application
The humidity indicators are either placed inside the packaging or are integrated into window panels.
When proper export packaging, including desiccants, is used at normal temperatures, the relative humidity quickly drops below 20%. The moisture indicators’ 30% display should thus be blue.
If this is not the case after 2-3 days, check the packaging for a leak, insufficient desiccant or excessively moist packaged goods.
The indicators’ colour reaction can, however, also be delayed, e.g. by excessively low packaging temperatures in winter, a lack of air circulation between the indicator and desiccant, or unsuitable films.
Reversible Humidity Indicators according to TL 6685-0003
Indicated RH | Supply-Number | Dimensions | Language | Packaging |
| 8 % relative humidity | 60 x 35 mm | E / D / F | Bundles of 250 pcs. | |
| 8% relative humidity cobalt-free | 60 x 35 mm | E / D / F | Bundles of 250 pcs. | |
| 8 % relative humidity self-adhesive, cobalt-free | 49 x 19 mm | E / D / F / I | 4.000 pcs. on a roll | |
| 40 % relative humidity self-adhesive | 27 x 20 mm | E / D | 800 pcs. on a roll | |
| 5/10/15 % relative humidity | 50 x 75 mm | E | 125 pcs. in tin | |
| 10-60 % relative humidity | 120 x 40 mm | E | E200 pcs. in tin | |
| 30-50 % relative humidity | 6685-00-752-8240 | 50 x 75 mm | E / D | 125 pcs. in tin |
| 20-80 % relative humidity | 6685-12-194-4969 | 50 x 160 mm | D | Bundles of 100 pcs |
Irreversible Humidity Indicator
Indicated RH | Supply-Number | Dimensions | Language | Packaging |
| 50-90 % relative humidity | 76 x 113 mm | E | 50 pcs. in tin |
Screw-in Humidity Indicators according to TL 6685-0003
Indicated RH | Supply-Number | Dimensions | Language | Packaging |
| 30-50 % relative humidity | 6685-12-181-2445 | Ø 10 cm | E / D / F | 12 pcs. in PE 48 pcs. in a box |
| 20-80 % relative humidity | 6685-12-337-1231 | Ø 10 cm | E / D / F | 10 pcs. in PE 40 pcs. in a box |
| 40-80% relative humidity | Ø 10 cm | E / D / F | 12 pcs. in PE 48 pcs. in a box | |
| 30-50% relative humidity | 6885-12-166-1928 | Ø 3/4 " | D | 125 pcs. in tin |
Info
Consulting | Service | High availability
TROPACK provides desiccant bags, desiccant cartridges, desiccant capsules and aluminium-composite film for a wide range of applications.
Custom designs tailored to your specifications are also available. Contact us for advice:
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TROPACK – you can count on us
TROPACK products comply with the highest quality standards according to DIN 55473 (12/2015). Our desiccants meet the relevant requirements established by the European Union (e.g. EC 1935/2004) and the US Food & Drug Administration FDA (e.g. 21 CFR part 175/part 177).
TROPACK quality standards are regularly verified in the form of DIN 55473 and ISO 9001 certifications.That’s something industry, the retail market and consumers alike can count on. TROPACK desiccants are food-safe, contaminant-free, odourless and renewable. (We expressly refrain from using dimethyl fumarate (DMF)!)
We’ll be glad to answer any questions you may have!
