TA378-HC-MHI Non-Reversible Delayed Response Maximum Humidity Indicator Discs

TA378-HC-MHI Non-Reversible Delayed Response Maximum Humidity Indicator Discs


Fits Any SAE AS26860 Type Humidity Indicator Plug

The TA378-HC-MHI marks a significant breakthrough in the monitoring of humidity inside long-term storage containers for sophisticated military/electronic and corrosion-susceptible equipment.

The element warns of dangerous humidity levels by staining a white disc a brilliant orange (turning later to a dark brown) when it has been exposed to humidity ranging from 55% RH for an eight hour continuous period to 85% RH for two hours. Humidity levels below 55% will not cause the indicator to stain, regardless of duration.

A non-reversible humidity indicator disc is often superior to a reversible humidity indicator disc because it maintains a record of past conditions. For example, a reversible indicator could trip during a cold night when the relative humidity level naturally rises, but then reverse itself during the warmer daytime hours when the indicator is most likely to be checked. In this case, the reversible indicator would give no sign that a dangerous humidity level had occurred overnight. By contrast, after a non-reversible indicator trips, it will always show that its humidity threshold has been exceeded.

The element is designed to be installed in the TA456 housing at the time the container is desiccated. It can also be used to replace color-change elements in TA356, TA350 or any similarly sized SAE AS26860 type Humidity Indicator Plug. Installation is accomplished with a 0.50 in. hex key wrench.

Each element is individually packaged in a MIL-B-22191 transparent barrier bag with desiccant. Quantities are overpacked in sealed metal containers.

Weight: 0.03 lbs. (14 grams)

TA378-HC-MHI Non-Reversible Delayed Response Maximum Humidity Indicator Disc drawing

Additional Information

Circle Card Diameter


Circle Card Type


Circle Card RH


Circle Card Special Fee Applies


Card Type



0.03 lbs (14 grams)