Humidity Indicator Plugs have been designed for easy mounting on reusable or long-term containers & enclosures to readily detect internal changes in relative humidity (RH) using a choice of reversible or maximum indicating color-change discs. Quickly installed with common hand tools, they are leak-proof & shock & vibration resistant.
Model TA350 for installation in rigid containers is of zinc-plated brass construction & the TA356 plug is of lighter weight, clear anodized aluminum construction for use in flexible barriers, but can be adjusted for rigid applications as well. Both models mount through a 1.05” (26 mm) diameter hole & meet SAE AS26860 Type II.
They are furnished with a 40% RH indicator disc as standard, but can be supplied with either a single spot disc for any number between 10% & 90% RH (in multiples of 10) or a multi-level indicator showing a range of percentages in pie-sector or spot styles.
Reversible color-change elements turn from blue to lavender to pink as the humidity increases & revert to blue when the humidity decreases. They can be reused as long as they are not exposed to humidity over 90% for periods of 36 hours or more, or become wet. Long-term calibration & accuracy is to within ±5% when read at 75°F (24°C), with a 2.5% correction factor for each 10°F higher or lower.
Irreversible color-stain maximum indicators for use in desiccated atmospheres warn that certain humidity levels have been exceeded & that the desiccant may need to be recharged or replaced. The element alerts users to dangerous humidity levels by staining a white indicator disc a brilliant blue which may turn dark blue when exposed to excessive humidity for a minimum time period.
Both types of elements may be installed in the same plug-type housings, which are suitable for almost all applications for Method II packaging of MIL-P-116. RFI/EMI shielding or CARC finish can be supplied as optional features. Housings without elements may also be used as observation windows.
