Tenney STRAT Altitude Simulation Test Chamber

Overview

The Tenney STRAT Altitude Simulation Test Chamber is an engineered environmental test system designed for precise replication of high-altitude atmospheric conditions—up to 200,000 feet (60,960 meters)—in combination with extreme thermal profiles ranging from –68°C to +177°C. Unlike conventional thermal aging chambers, the STRAT series integrates controlled vacuum capability with high-fidelity temperature regulation and optional humidity control (on xxSTR configurations), enabling simultaneous simulation of low-pressure, low-oxygen, and thermally stressed environments. This capability is essential for validating aerospace components (e.g., avionics, seals, composites), medical devices requiring sterilization-cycle compatibility, and electronic systems subject to rapid decompression or cold-soak scenarios. The chamber operates on fundamental principles of gas law-based pressure control (via capacitance manometry) and closed-loop thermal management using cascade refrigeration and open-wire resistive heating—ensuring reproducible, traceable, and auditable test conditions compliant with MIL-STD-810H, RTCA DO-160G Section 4 (Altitude), and ASTM D3574 Annex A4.

Key Features

• Altitude simulation up to 200,000 ft (8.28 Torr at 100,000 ft baseline), achieved via automated vacuum and exhaust valve actuation synchronized with real-time capacitance pressure feedback
• Dual-stage cascade refrigeration system with two semi-hermetic compressors for stable sub-zero operation down to –68°C under vacuum
• Continuously welded 304 stainless steel interior liner providing full airtight integrity and corrosion resistance across repeated thermal-vacuum cycling
• Synergy Quattro controller featuring 320×240 color touchscreen interface, embedded Windows CE OS, and dual-channel PID with adaptive tuning for load-dependent thermal compensation
• Integrated I/O architecture (OLYMPUS module) supporting discrete alarm outputs, analog signal monitoring, and external device interlocks per IEC 61508 SIL2 requirements
• Comprehensive data governance: onboard flash storage, USB export, RS-232 serial logging, and TCP/IP Ethernet (10/100) with Modbus TCP and HTTP API support for LIMS/SCADA integration
• Pressure safety architecture including redundant overpressure venting, vacuum loss detection, and independent chamber overtemperature cutout circuits

Sample Compatibility & Compliance

The STRAT chamber accommodates test specimens ranging from small PCB assemblies to full-size UAV subsystems, with internal volumes spanning 5–64 ft³ (0.14–1.81 m³). Its vertical airflow design—featuring downward recirculation through perforated plenums—ensures uniform thermal distribution (±0.3°C) even under dynamic vacuum transitions. All models comply with UL 61010-1 (Safety Requirements for Electrical Equipment for Measurement, Control, and Laboratory Use) and meet electromagnetic compatibility per FCC Part 15 Class A. For regulated industries, the controller supports 21 CFR Part 11-compliant audit trails—including user login logs, parameter change timestamps, and electronic signature fields—when deployed with validated software configuration. Humidity-equipped xxSTR variants adhere to ISO 17025 calibration traceability requirements for RH sensors and are suitable for accelerated aging per IPC-TM-650 2.6.25 (Thermal Vacuum Cycling).

Software & Data Management

The Synergy Quattro controller embeds a deterministic real-time kernel with non-volatile flash memory for persistent program storage (unlimited cycles, >100,000-step capacity). Test protocols are authored via intuitive English-language prompts; each step defines target pressure, temperature, ramp rate, dwell time, and humidity setpoint (if applicable). Data acquisition records setpoints and actual values at user-configurable intervals (1 sec to 60 min), with timestamped CSV export via USB or network transfer. Remote diagnostics leverage built-in web server functionality—accessible via standard browser—for live parameter viewing, alarm status, and firmware version verification. Optional cloud gateway modules enable MQTT-based telemetry to AWS IoT Core or Azure IoT Hub, satisfying Industry 4.0 interoperability frameworks without compromising on-premise data sovereignty.

Applications

• Aerospace: Validation of pressure-sensitive gaskets, MEMS barometers, oxygen regulators, and composite material outgassing per ECSS-Q-ST-70-02C
• Defense Electronics: MIL-STD-810H Method 500.7 (Low Pressure) and Method 501.7 (Temperature) combined stress testing
• Medical Devices: Sterilization cycle development for implantable electronics exposed to transport-at-altitude conditions
• Automotive: EV battery thermal management system performance under simulated high-elevation charging scenarios
• Research: Fundamental studies of polymer viscoelastic relaxation kinetics under coupled thermal-vacuum loading
• Quality Assurance: In-process verification of hermetic seal integrity in microelectromechanical packaging

FAQ

What altitude range does the STRAT chamber simulate?
It replicates ambient conditions from sea level up to 200,000 ft (60,960 m), with standard operational baselines at 100,000 ft (8.28 Torr) and 60,000 ft for combined thermal-vacuum profiles.
Is humidity control available on all STRAT models?
No—only xxSTR-configured units include the corrosion-resistant steam-jet humidification system, rated for 20–98% RH at temperatures up to +85°C.
How is temperature uniformity maintained during vacuum operation?
Through vertically oriented forced-air recirculation with turbulence-dampening baffles and dual-point sensor averaging, ensuring ±0.3°C uniformity even at <10 Torr.
Does the controller support regulatory audit requirements?
Yes—the Synergy Quattro includes configurable electronic signatures, immutable event logs, and role-based access control aligned with FDA 21 CFR Part 11 and EU Annex 11 expectations.
Can the chamber integrate with existing plant MES or SCADA infrastructure?
Absolutely—native Modbus TCP, HTTP RESTful API, and optional OPC UA drivers enable bidirectional communication with Siemens SIMATIC, Rockwell FactoryTalk, or Schneider EcoStruxure platforms.