MIL-STD-810 Method 503 Temperature shock testing
MIL-STD-810, Method 503 covers temperature shock testing to evaluate performance and durability of equipment when subjected to rapid and extreme temperature changes. The test engineering team at Clark Testing conducts MIL 810, Method 503 to assess equipment's ability to withstand sudden temperature transitions without sustaining damage or exhibiting performance degradation.
Method 503 temperature shock test typically involves subjecting the equipment to rapid and extreme temperature changes, alternating between high and low temperatures. The temperature levels, dwell times, and number of cycles are specified based on the equipment's intended use and the expected environmental conditions. Clark’s test engineers and lab technicians will identify potential issues related to thermal stress, material expansion/contraction, seal integrity, and component functionality during temperature transitions.
MIL-STD-810 503 temperature shock testing specifies different temperature shock levels that are categorized based on the anticipated temperature transitions. Our test team will determine the temperature shock levels by considering factors such as the equipment's operating temperature range, storage temperature requirements, and deployment scenarios. These levels help ensure that the equipment is tested under relevant and representative temperature shock conditions.
The standard defines acceptance criteria for temperature shock testing. The criteria may include allowable temperature differentials, component functionality during temperature transitions, material integrity, seal integrity, and other performance parameters. The equipment is assessed based on its ability to withstand the specified temperature shocks without sustaining damage or exhibiting performance degradation beyond acceptable limits.
This method is, essentially, surface-level tests that typically addresses:
a. The transfer of material between climate-controlled environment areas and extreme external ambient conditions or vice versa.
b. Ascent from a high temperature ground environment to high altitude via a high performance vehicle (hot to cold only).
c. Air delivery/air drop at high altitude/low temperature from aircraft enclosures when only the external material
The effects of thermal shocks are usually more severe near the outer portions of material. Typically the further from the surface the slower and less significant are the thermal changes. Transit cases, packaging, etc., will lessen the effects of thermal shock on the enclosed material even more. Sudden temperature changes may either temporarily or permanently affect the operation and functionality of material.
Method 503.5 includes one test procedure with four variations – essentially in the length of the test and the shock itself. The Method employs constant temperature at each of the extreme shock conditions because, in many instances, the thermal shock itself so outweighs the other thermal effects that the test may be performed using two constant temperatures.
When selecting this thermal shock procedure, consider the expected exposure temperatures in service and the materiel's logistic or deployment configuration. For procedure variations, the four procedure variations all involve temperature conditioning and performance testing. They differ on the number of shocks that, based on the Life Cycle Environmental Profile LCEP, can vary from one shock (1/2 cycle) to six or more shocks (three or more cycles).
Having selected this method (based on the test item's requirements documents) complete the process by identifying appropriate parameter levels and applicable test conditions and techniques for the procedure. Base these specifications on the requirements documents, the Life Cycle Environmental Profile (LCEP), and information provided with this method.
Method 503 Temperature Shock Test Exposure situations to consider when selecting test levels:
- Aircraft flight exposure: This is appropriate if the material is to be exposed to desert or tropical ground heat and possible direct solar heating and, immediately afterwards, exposed to the extreme low temperatures associated with high altitude. If not expended, the test item could subsequently be exposed to a potential thermal shock when the platform aircraft returns to a hot ambient environment. In addition, if not expended, the item could also be subjected to multiple thermal shocks.
- Air delivery – desert: This is appropriate for material that is delivered over desert terrain from unheated, high-altitude aircraft, but use the ambient air temperature (no solar loading).
- Ground transfer: ambient to or from either cold regions or desert. This is intended to test material for the effects of movement to and from ambient conditions and cold regions or desert environments.
- Engineering design: This is used to detect issues related to marginal design.
The test engineering team at Clark Testing can help ensure that equipment will function and maintain its performance while operating in a thermal shock environment. Call or email the Clark Dynamics Test Laboratory for assistance in developing a test plan and conducting the appropriate test to validate your equipment in accordance with MIL-STD-810G Method 503.5.
Test Set Up
In house custom design and fabrication capabilities (machining and welding) to ensure test fixtures accurately simulation environmental conditions. FEA capabilities to support fixture design along with welding, fabrication & machining services. Multiple vibration adapter plates and prefabricated test fixtures help to streamline the testing process.
Instrumentation capabilities including accelerometers and strain gages with multi-channel control and data acquisition equipment ensuring accurate test data is being recorded. All instrumentation and equipment is provided with measurement uncertainty and compliant with Clark’s ISO 17025-2017 Quality Program.
Lab technicians and engineers record daily test activities to register all activities, events, and responses during the test. The daily test logs along with test data, pictures and test procedures are included in comprehensive test report that is the industry standard.
We work closely with you to validate engineering, ensure quality, analyze test spectrums, and execute accurate testing programs for successful qualification and marketing of your product.