Reversible humidity-control window for checking flexible barrier packaging without opening it.
Description
The TL399 is a Herrmann-type humidity-control window that provides a visible warning when moisture inside a package reaches or passes the indicator card’s marked relative-humidity limits.
Designed for flexible barrier pouches made from PE or aluminium-composite film, it allows the indicator to be checked from outside without opening the sealed packaging. The card’s individual indicator points change colour in response to humidity. This response is reversible: as conditions become drier, the points return to their earlier colour.
Installation and supplied accessories
The window screws into the packaging film for straightforward installation using the supplied key. The assembly comes with sealing rings and humidity-indicator cards.
Typical applications
Uses include protective packaging for electronics and optical instruments, export shipments, bulk packaging, military and aerospace equipment, and pharmaceutical products.
Indicator-card options
- 3 points: 30 / 40 / 50% RH
- 5 points: 40 / 50 / 60 / 70 / 80% RH
- 7 points: 20–80% RH
Dimensions and specification
The outer diameter is 120 mm and the indicator disc is 90 mm in diameter. The window meets military specification TL 6685-0007.
Further information
| Mounting Hole Size | 4 inches diameter hole |
|---|---|
| Indicator levels | 3-point option: 30 / 40 / 50% RH, 5-point option: 40 / 50 / 60 / 70 / 80% RH, 7-point option: 20–80% RH |
| Indicator Behaviour | Reversible |
| Diameter | 120 mm (outer diameter) |
| Indicator Disc | 90 mm diameter |
| Mounting | Screw-in fitting for flexible PE or aluminium-composite barrier films |
| Mounting Tool | Installation key supplied |
| Mounting Hardware | Sealing rings and indicator cards supplied |
| Material | Plastic |
| Finish | No Finish |
Drawings available on request.
Request drawings
