How do I see in advance what the inside of the test chamber will look like to predict any test setup obstacle that may be of concern for MIL-STD requirements?
As always, feel free to contact our technical staff for information pertaining to product/cable layout, product positioning, typical environmental/ambient conditions, and chamber ventilation so you are comfortable with meeting the test setup requirements specified in MIL-STD. See MIL-STD testing illustrations that show the test chamber layout.
Where will the support test equipment be positioned so I am able to continuously monitor my product’s performance throughout the testing?
In most cases, all support test equipment will be positioned outside the test chamber adjacent to the test chamber bulkhead panel. Our MIL chamber bulkhead panel is able to accommodate various types of cable terminations, including having special bulkhead sub-panels fabricated by our in-house machinist for unique cabling interfacing needs. When necessary, MET Labs can use our mobile Faraday cabinets to electrically-shield unwanted RF ambient signals outside the test chamber. These undesirable ambient signals can causes interference with the test results by means of cable conduction into the test chamber bulkhead panel. See MIL-STD testing illustrations that show the support equipment positioning.
Why does the MET Laboratories Test Engineer insist on cutting my product’s cabling for MIL-STD testing?
In most cases, MIL-STD testing requires the test engineer to couple RF stimulus into the product’s ports by means of capacitive and inductive coupling methods to determine the product’s ability to withstand adverse conditions. While MET Labs is interested in maintaining the product’s original design, sometimes the MIL spec requires the test engineer to splice in coupling transformers or coupling capacitors onto the shield of the cable for injection purposes. MET Laboratories recommends to all of our MIL-STD customers to supply duplicate cabling, when needed, with one set to be typical installation lengths and the other set to be used for splicing.
Who can I speak with regarding test scheduling?
Requests for a MIL test schedule or rescheduling can be made directly to the MET Laboratories Project Coordinator. The Project Coordinator’s main responsibility is to be the liaison between the customer and the appropriate internal test lab to insure that the project goes smooth from beginning to end. In most cases, the Project Coordinator must team-up with the MIL Group Coordinator to validate the test lab’s resource availability in the requested test time-frame.
What are MET Laboratories radiated immunity test capabilities, and how do you insure a safe test environment from high radiating electromagnetic fields?
MET Laboratories’ radiated immunity test capabilities are over 200 V/m (166 dBµV/m) from 2 MHz to 18 GHz. Additionally, MET can offer the MIL-STD “optional” test frequency range between 18-40 GHz. The 200 V/m radiated immunity test service covers EMI requirements from the Military, Commercial Aircraft, and Automotive industries.
To insure a safe test environment for our customers and test engineers, MET Laboratories utilizes an RF interlock safety circuit design to inhibit transmission while the test chamber doors are ajar. This safety feature prevents inadvertent exposure to these high power electric fields, and provides a visual indication to when the test is in progress.
When MIL-STD emission measurements are performed, how do you insure an ambient-free condition exists before measurements are recorded?
With our MIL-STD test chamber, MET Laboratories is able to provide over 100 dB of isolation to outside ambient signals to keep them from interfering with measurements. In other words, before we perform emission measurements, we isolate unwanted signals from the data by insuring our test chamber satisfies IEEE-299 attenuation requirements. Combining our MIL test chamber and very sensitive measurement receivers, MET Laboratories is able to detect and quantify even the slightest “whisper” from electronic products.
In addition to our ambient-free MIL test chamber, MET Laboratories can accommodate almost all types of AC/DC power your product may require, from Delta/Wye AC 3 phase 480VAC to high voltage DC input power. All AC/DC input power the product receives is heavily filtered to provide clean electrical power to the EUT, as to not misinterpret ambient noise from the product’s real emissions. While testing, our test engineers can switch various AC/DC power inputs to the EUT remotely through our custom-designed power relay network bank to reduce the time for manual removal of power.