MIL-STD-810 – the ideal tool for demanding environments

Purpose/Summary:
Method 501.7 is used to evaluate the effects of high temperatures on the safety, integrity, and performance of military equipment during storage, operation, and tactical readiness. This method is primarily used in the defense, aerospace, and energy industries to ensure reliability under heat-intensive conditions.

Application:
e.g. viscosity, lubricants, stresses caused by different thermal expansion, mechanical damage, outgassing of composite materials and coatings, stability of electronic circuits, etc.

Test scenarios:

• Procedure I – Storage: The material is exposed to high temperatures in a storage configuration to detect structural changes. After at least seven cycles, a functional test is performed under standard conditions.
• Procedure II – Operation: The device is operated at constant or cyclic high temperatures. The aim is to check functionality during thermal stress, especially at maximum temperature response.
• Procedure III – Tactical standby to operation: After exposure to maximum non-operating temperature, there is a rapid transition to operating temperature. The device must be ready for immediate use – without active cooling.

Suitable Weiss Technik products:
TempEvent or ClimeEvent (with climate range extension and compressed air dryer for humidity <10% RH), R devices, MUR and LabEvent.

• Parameter Example values
• Ambient air temperature (basic hot): 30 to 43 °C
• Induced temperature (basic hot): 30 to 63 °C
• Ambient air temperature (hot and dry): 32 to 49 °C
• Induced temperature (hot and dry): 33 to 71 °C
• Humidity (basic hot): 14 to 44% RH
• Humidity (hot and dry): 1 to 8% RH
• Temperature change rate: ≤ 3 °C/min
• Test duration Procedure I (storage): &; 7 cycles
• Test duration Procedure II (operation): > 3 cycles

Purpose/Summary:
Method 502.7 defines how to evaluate devices that are exposed to low temperatures. It outlines three key procedures—storage, operation, and handling—each of which simulates real-world exposure to cold. This standard is essential for the defense, aerospace, and energy industries to ensure reliability under cold conditions.

Application:
These include hardening and embrittlement of materials, mechanical damage or malfunctions due to varying thermal expansion, mechanical damage, lubricant failure, and performance changes in electronic components.

Test scenarios:
Various test methods for use, storage, and operational readiness. Ensuring operational readiness at low temperatures.

Cycles:
Consistent temperatures for test specimens with additional cycle at room temperature if necessary.

Suitable Weiss Technik products:
TempEvent, LabEvent, R devices and MUR

Special feature:
The recommended test duration according to MIL-STD-810H is 4 hours after stabilization for non-hazardous or non-safety-critical (non-life-sustaining) materials. Ammunition, rubber, and plastics may deteriorate further after stabilization at low temperatures. For these materials, a minimum duration of 72 hours after temperature stabilization is recommended.

• Parameter Example values
• Ambient air temperature (basic cold) -21 to -32 °C
• Induced temperature (basic cold) -25 to -33 °C
• Ambient air temperature (cold) -37 to -46 °C
• Induced temperature (cold) -37 to -46 °C
• Ambient air temperature (extreme cold) -57 °C
• Induced temperature (extreme cold) -57 °C
• Temperature change rate ≤ 3°C/min
• Test duration (not dangerous) > 4 hours
• Test duration (Dangerous) > 72 hours

Purpose/Summary:
Method 503.7 (temperature shock) evaluates the ability of a test specimen to withstand sudden, extreme changes in ambient temperature. It simulates rapid transitions between hot and cold environments to evaluate structural integrity and operational reliability. This method is important for defense, aerospace, and industrial electronics, where devices may be exposed to abrupt temperature fluctuations during transport or use.

Application:
This method is used to identify failure mechanisms in the event of sudden, extreme temperature fluctuations. These include the breakage of sensitive components, the deformation or failure of mechanical parts due to varying thermal expansion, and the cracking of coatings or the leakage of sealed areas.

Chemically, this can lead to the separation of substances or impair protective barriers. Component properties can change electronically; condensation or frost can cause short circuits or mechanical defects.

Test scenarios:

• Procedure I – Equipment in storage or in transit: Assessment of the risk of physical damage due to thermal shocks during non-operational phases. The device is moved back and forth between two extreme temperatures while it is not connected to a power source. The process is used for warehouse storage, air transport, and logistics without a power connection.
• Procedure II - Equipment in operational configuration: Evaluates operational performance during or after a temperature shock. The item is supplied with power during or immediately after exposure to extreme temperatures. This is especially relevant for in-service systems, mission-critical electronics, and aerospace avionics.

Cycles:
Single cycles or multiple cycles

Suitable Weiss Technik products:
ShockEvent T or D (flap shock); for higher weights, TempEvent with > 10 K/min

Special feature:
Test Setup

• Use two temperature chambers or a single chamber with two zones. Ensure a rapid transition between the hot and cold zones (preferably ≤ 1 minute). Monitor the internal temperature of the test object.
• If test specimens with greater weight are being tested, it may be necessary to use the two-chamber method. The test specimen is moved using a pallet truck (temperature change then > 1 minute).

• Parameter Example values
• Temperature limits Based on climate categories (e.g., -51°C to +71°C)
• Transfer time between chambers ≤ 1 minute (typical)
• Number of cycles 3 to 5 (standard), up to over 20 for extended tests
• Stabilization period Until the chamber’s internal temperature is reached
• Relative Humidity It is not controlled except in cases where there is a risk of condensation

Purpose/Summary:
The “humidity” method describes procedures for testing the resistance of materials to warm, humid environments. It comprises two main processes: induced (storage and transport) and natural cycles, each simulating different humidity conditions. This method is crucial for industries such as defense, aerospace, and electronics, where the reliability of equipment under humid conditions is critical.

Application:
For oxidation, chemical reactions, interaction between condensation and coatings, changes in physical properties (e.g., delamination, degradation of explosives and propellants due to absorption), and short circuits

Test scenarios:

• Procedure I - Induced (storage & transit): This procedure evaluates the resistance of the material to moisture during storage and transport, as well as under natural environmental conditions.
• Procedure II (enhanced procedure): This procedure is designed to produce representative effects that typically occur under elevated temperature and humidity conditions, without precisely replicating naturally occurring conditions.

Suitable Weiss Technik products:
ClimeEvent

• Parameter Example values
• Temperature range 24 °C to 71 °C
• Relative Humidity 14% to 100% RH
• Test duration 10 to 180 cycles (days)
• Air velocity 0.5 to 1.7 m/s
• Chamber control accuracy > ±0.6°C