MIL-STD 461 & DO-160 Chambers

PPG aerospace engineered materials cuming lehman emc chambers MIL-STD 461 & DO-160 Chambers

Cuming-Lehman Chambers MIL-STD 461E/F test chamber is specially designed for testing in accordance with the military standard. 

MIL-STD 461 SHIELDING SYSTEM

Our MIL-STD 461F/DO-160 enclosure is modular panel construction; the panels are a laminate of 26 gauge, electrolytically deposited zinc sheet steel laminated to both surfaces of ¾” thick solid, (structural) core material. These panels have a flame spread of 20 minutes or less as rated by Underwriters Laboratories, Inc.  The panels are joined by specifically designed framing members that clamp the edges of the panels and provide constant, low impedance joints with the shielding elements of the chamber. Weld nuts are on 3” centers and our corners are welded; no screws are used and nothing penetrates our chamber. 

Shielding Effectiveness:

Magnetic FieldsElectric FieldPlane WaveMicrowave
1KHz – 28dB1KHz – 120dB100MHz – 110 + dB1GHz – 110 + dB
10KHz – 58dB10KHz – 120dB400MHz – 110 + dB10GHz – 110 + dB
200KHz – 100dB100KHz – 120dB1GHz – 110 + dB18GHz – 110 + dB
1MHz – 110dB10MHz – 120dB  
 100MHz – 120dB  


A typical Cuming-Lehman Chambers MIL-STD 461E/F test chamber is partially lined with Cuming Microwave’s SFC-24EM absorbers. The MIL STD/DO-160 specification calls for both the transmit and receive end walls to be fully lined, the walls and ceiling are covered from the receive end wall out approximately 10 feet. A floor patch is also provided for susceptibility testing.  

MIL-STD 461F PERFORMANCE:

Specially Optimized Absorber

The SFC-24EM product is similar to Cuming Microwave’s standard CRAM SFC pyramidal grades, but the tips of the pyramids are truncated. This saves space in small chambers and provides a more rugged product, eliminating the possibility of tip breakage. C-RAM SFC EM products are specifically optimized for low frequency applications and are used mainly in chambers used for emissions and immunity testing.

C-RAM SFC-24 EM exceeds the requirements for MIL-STD 461F and DO-160 chambers. The MIL-STD 461F specification lists the following performance requirement:

MIL-STD 461F/DO-160 Frequency Specification
80MHz – 250MHz     6dB
>250MHz                  10dB