Moisture control is key for storing and shipping sensitive aerospace and defense components

BY Jim McCorry

Moisture has long been the enemy of aerospace and defense electronics and electro-optics in systems, such as missiles, munitions, avionics, imaging systems and optical guidance systems. Sensitive electro-optical equipment can be damaged by moisture—not only from corrosion of wiring and metal parts, but also from condensation and fog on lenses and mirrors.

To prevent moisture from contaminating equipment during transport and storage, aerospace and defense engineers historically have designed air-tight shipping containers able to withstand large pressure, temperature, and altitude differences. These heavy, bulky, steel containers, however, are costly to build and ship. A better solution involves controlled breathing systems that allow for lighter, less bulky containers.

The key elements of a controlled breathing system include a breather valve, which controls pressure, vacuum, and moisture entry; a desiccator, which removes moisture; and a humidity indicator, which indicates when to replace a desiccator when it’s saturated and humidity levels begin to rise. The breather valve basically allows a sealed enclosure to “burp” a little air in and out, to equalize internal and external air pressure.

While the moisture problem in shipping containers has long been solved with the use of these controlled breathing systems, the field of battle is evolving again. For mission-critical functionality, reliability, and longevity, the leading edge of moisture control is moving from inside the container to inside the equipment.

The continual pressure to improve the functionality, reliability, and longevity of mission-critical, electro-optical devices is now resulting in controlled breathing systems being used for moisture control directly in the equipment. After all, what is a camera housing or missile casing other than a container for the sensitive components inside?

“Reducing moisture in the presence of electronics and optical imaging systems is critical for performance and longevity,” says James Weaver, a mechanical engineering manager at thermal imaging specialist FLIR Systems in Wilsonville, Ore. “With superior moisture control in the shipping container and even the equipment enclosure itself, you can operate longer and more reliably in harsher and harsher environments. Everything is demanding higher definition, more functionality, and more processing capability in a smaller, more rugged package.”

While a traditional shipping container has plenty of room for a separate breathing valve, desiccant, and humidity indicator, space was at a premium for FLIR’s Star Safire HD system, which features megapixel thermal, daylight, and low-light cameras with high-magnification optics, laser payloads, and a fully integrated inertial measurement unit to locate targets precisely.

“For us, every inch and every ounce must provide functionality,” Weaver says. “We didn’t have the luxury of using a large panel to put three separate, controlled breathing system modules in our device. To free up space for enhanced capabilities on the Star Safire HD system, we sought to combine the moisture control modules.”

AGM Container Controls in Tucson, Ariz., teamed with FLIR to develop a controlled breathing system, called the TA340, with a combined breather valve, desiccator, and humidity indicator for space-efficient moisture control.

Incorporating a humidity indicator and two-way breather valve all in the same aluminum housing not only saved space, but also helped to avoid drilling an additional hole in the case. With only one mounting hole in the equipment, potential leak paths in the equipment were reduced, which makes its moisture control capabilities even more reliable.

Since the TA340’s desiccant cartridge is mounted on the back end of the valve, when it breathes air in, the air goes directly over the desiccant bed to efficiently capture moisture on entry. For ease of desiccant replacement, the system is also designed to accept an externally accessible replacement desiccant cartridge.

“It’s critical for anyone servicing a controlled breathing system to have an externally accessible replacement desiccant cartridge,” Weaver says. “Besides being easier and quicker, it minimizes moisture entry from outside air since the entire enclosure does not have to open. I’m glad we were able to include this in its compact design.

“Since the TA340’s 3-in-1 controlled breathing system reduced its ‘footprint’ by two-thirds compared to separate moisture control systems, we had more space to enhance our thermal imaging, visible imaging, and laser elimination capabilities,” Weaver says.

On a more recent project, AGM again teamed with FLIR and added RFI/EMI shielding to the compact, controlled breathing system. “RFI/EMI shielding enables an electronically tighter enclosure, with even less susceptibility,” Weaver says. “It should allow its use on installations with higher emissions, and should shield customers from noise made on more sensitive equipment.”

As the aerospace and defense arena demands ever more functionality and ruggedness in a smaller package, the leading edge of moisture control will increasingly move from inside the container to inside the equipment for mission-critical functionality, reliability, and longevity. The aerospace and defense engineers who keep pace with this trend will be ready to deliver.

Jim McCorry is the director of business development at AGM Container Controls Inc. in Tucson, Ariz. Contact the company online at

More Military & Aerospace Electronics Current Issue Articles
More Military & Aerospace Electronics Archives Issue Articles

Get All the Military Aerospace Electronics News Delivered to Your Inbox or Your Mailbox

Subscribe to Military Aerospace Electronics Magazine or email newsletter today at no cost and receive the latest information on:

  • C4ISR
  • Cyber Security
  • Embedded Computing
  • Unmanned Vehicles

Get All the Military Aerospace Electronics News Delivered to Your Inbox or Your Mailbox

Subscribe to Military Aerospace Electronics Magazine or email newsletter today at no cost and receive the latest information on:

  • C4ISR
  • Cyber Security
  • Embedded Computing
  • Unmanned Vehicles

Military & Aerospace Photos

Most Popular Articles

Related Products

XPedite7574 | 5th Generation Intel® Core™ i7 Broadwell-H Processor-Based Conduction- or Air-Cooled 3U VPX-REDI Module

The XPedite7574 is a high-performance, 3U VPX-REDI, single board computer based on the 5th genera...

XCalibur1645 | Freescale Eight-Core P4080 Processor-Based Conduction-Cooled 6U VPX Module

The XCalibur1645 is a high-performance, 6U VPX, single board computer supporting Freescale QorIQ ...

XCalibur5090 | Dual Virtex-7 Based Digital Signal Processing 6U LRM FPGA with Quad 2500 MSPS DAC and 3200 MSPS ADC

The XCalibur5090 is a high-performance, reconfigurable, conduction-cooled 6U LRM module based on ...


Widely used for applications in the aerospace, electronic and OEM industries, Master Bond EP121CL...

FLATRACK™ Ethernet I/O DAQ Platform

FLATRACK™ Ethernet I/O DAQ Platform accommodates installation of up to four I/O boards, completes...

PowerDNR RACKtangle®

3U Gigabit Ethernet Data Acquisition and control rack United Electronic Industries allows the ins...


Four-Slot, Military Style I/O Chassis with Military/Rugged 38999 connectivity, 100% COTS solution...


Dual Channel MIL-STD-1553 interface board for Cube I/O chassis with 2 independent, dual redundant...

PowerDNA-PPC5 Cube

5-layer, 100Base-T I/O, Data Acquisition and Control Cube with PowerPC CPU and SD slot. Has slots...


Half-width 3U Gigabit Ethernet Data Acquisition and control chassis allows the installation of up...

Related Companies

LiquidCool Solutions

LiquidCool Solutions is a technology development firm with patents surrounding cooling electronics by total immersion...

Curtiss-Wright Defense Solutions

About Curtiss-Wright Defense Solutions Curtiss-Wright Defense Solutions (CWDS) is a long established techno...

Southwest Antennas

Southwest Antennas designs and manufactures high-performance RF & Microwave antennas and accessories designed for tod...

CORWIL Technology Corp

CORWIL Technology, the premier US based, IC assembly and test services subcontractor, offering full back-end assembly...

Delphi Automotive PLC

Delphi provides military, aerospace and commercial connector products.


IndustryARC primarily focuses on Cutting Edge Technologies and Newer Applications of the Market. Our Custom Research ...

Thermotron Industries

Thermotron is a manufactures environmental test chambers, vibration test systems, HALT/HASS equipment, and functional...

United Electronic Industries Inc

UEI is a leader in the PC/Ethernet data acquisition and control, Data Logger/Recorder and Programmable Automation Con...

RPMC Lasers Inc

Offers 1500 DPSS lasers, lamp lasers, fiber lasers and diode lasers. Provides, ultrafast, picosecond, nanosecond, cw ...

Reutech Communications

Looking for a material to replace aluminum in the housings of military radios and module covers. Requirements: tough,...


Harsh Environment Protection for Advanced Electronics and Components

This webinar will offer an opportunity to learn more about ultra-thin Parylene conformal coatings – how they are applied, applications they protect today, and the properties and benefits they offer, includin...

New Design Tools That Help You Develop Radar That Sees the Un-seeable and Detects the Undetectable

Xilinx EW/ISR System Architect, Luke Miller, has new tricks and he’s going to tell you all about them in a new Xilinx Webinar—for free. His Webinar will cover new ways to implement Radar functions including ...
Sponsored by:

Press Releases


Curtiss-Wright Corporation today announced that its Defense Solutions division has received a contract from Sierra Nevada Corporation (SNC) to supply its small form factor ...

Innovative Integration Announces the FMC-Servo

Camarillo, CA June 19, 2015, Innovative Integration, a trusted supplier of signal processing and data acquisition hardware and software solutions, today announced the FMC-S...


Curtiss-Wright Corporation today announced that its Defense Solutions division has further enhanced its innovative VRD1 high definition (HD) video management system (VMS) w...

All Access Sponsors

Mil & Aero Magazine

August 2015
Volume 26, Issue 8

Download Our Apps




Follow Us On...


Military & Aerospace Electronics

Weekly newsletter covering technical content, breaking news and product information

Cyber Security

Monthly newsletter covering cyber warfare, cyber security, information warfare, and information security technologies, products, contracts, and procurement opportunities

Defense Executive

Monthly newsletter covering business news and strategic insights for executive managers

Electronic Warfare

Quarterly newsletter covering technologies and applications in electronic warfare, cyber warfare, optical warfare, and spectrum warfare.

Embedded Computing Report

Monthly newsletter covering news on embedded computing in aerospace, defense and industrial-rugged applications

Unmanned Vehicles

Monthly newsletter covering news updates for designers of unmanned vehicles