Humidity indicator plugs detect changes in RH

Edited by the Processingtalk editorial team Oct 11, 2005

AGM Humidity Indicator Plugs for reusable or long-term containers readily detect internal changes in relative humidity (RH) using a choice of reversible or maximum indicating colour-change discs

AGM Humidity Indicator Plugs have been designed for easy mounting on reusable or long-term containers and 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 and shock and vibration resistant.

Model TA350 for installation in rigid containers is of zinc-plated brass construction and the TA356 plug is of lighter weight, clear anodised aluminium 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 and 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 and 90% RH (in multiples of 10) or a multi-level indicator showing a range of percentages in pie-sector or spot styles.

Reversible colour-change elements turn from blue to lavender to pink as the humidity increases and revert to blue when the humidity decreases.

They can be re-used as long as they are not exposed to humidity over 90% for periods of 36 hours or more, or become wet.

Long-term calibration and accuracy is to within +/-5% when read at 75F (24C), with a 2.5% correction factor for each 10F higher or lower.

Irreversible colour-stain maximum indicators for use in desiccated atmospheres warn that certain humidity levels have been exceeded and 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.