Axetris EMIRS Series Infrared Thermal Source

Overview

The Axetris EMIRS Series Infrared Thermal Source is a micro-electro-mechanical systems (MEMS)-based broadband infrared emitter engineered for high-stability, low-power, and long-lifetime operation in gas sensing applications. Unlike conventional filament-based or ceramic IR sources, the EMIRS leverages a precisely patterned resistive heating element deposited on a silicon membrane and coated with a dielectric thin-film layer—enabling near-ideal blackbody-like spectral emission across 2–16 µm. This spectral coverage aligns with fundamental vibrational absorption bands of key industrial and medical gases, including CO, CO₂, CH₄, NH₃, NOₓ, SO₂, SF₆, VOCs, anesthetic agents (e.g., isoflurane, sevoflurane), ethanol, and refrigerants. The device operates without mechanical choppers due to its intrinsic fast electrical modulation capability—reducing system complexity, eliminating moving parts, and enhancing signal-to-noise ratio in lock-in detection architectures.

Key Features

• MEMS-integrated thermal emitter with calibrated blackbody radiation profile (emissivity >0.95 across 2–16 µm)
• Electrically modulated output (kHz-range modulation bandwidth), enabling synchronous detection without optical choppers
• Hermetically sealed TO-39 metal package with optional integrated reflector cup or protective cap
• Customizable infrared-transmissive window materials: sapphire (broadband, durable), CaF₂ (UV–mid-IR), BaF₂ (extended mid-IR), or Ge (long-wave IR up to 16 µm)
• Low power consumption (10% wall-plug efficiency into 2π sr)
• Proven reliability under accelerated lifetime testing; >10,000 hours MTTF at nominal operating conditions
• Compliant with IEC 60747-3-7 Class 7M3 for MEMS robustness (mechanical shock, vibration, thermal cycling)—excluding variants with CaF₂/BaF₂ windows due to material brittleness constraints

Sample Compatibility & Compliance

The EMIRS Series is optimized for integration into compact, field-deployable NDIR (Non-Dispersive Infrared), PAS (Photoacoustic Spectroscopy), and ATR-FTIR (Attenuated Total Reflection Fourier Transform Infrared) gas analyzers. Its stable spectral output supports quantitative trace gas analysis per ISO 8573-1 (compressed air purity), ASTM D6245 (CO₂ in indoor air), and EN 14687 (medical gas monitoring). For regulated environments—including clinical diagnostics and industrial safety—the source enables system-level compliance with IEC 62304 (medical device software lifecycle), ISO 13485 (QMS), and FDA 21 CFR Part 11 when embedded within validated instrument platforms featuring audit-trail-capable firmware. Window material selection directly impacts spectral transmission fidelity and environmental durability: sapphire is recommended for harsh or humid conditions; Ge is preferred for long-wave detection where atmospheric absorption is mitigated by short-path cells.

Software & Data Management

While the EMIRS itself is a passive emitter requiring external driver circuitry, Axetris provides reference design schematics and characterization datasets (including spectral radiance curves, thermal time constants, and modulation transfer functions) compatible with common embedded control frameworks (ARM Cortex-M, TI MSP430). OEMs integrate these into host instrument firmware supporting real-time temperature compensation algorithms and closed-loop current regulation. When deployed in analyzers with GLP/GMP-compliant data handling, the source’s deterministic response enables full traceability—from raw detector voltage to concentration output—via timestamped calibration logs, drift correction coefficients, and configurable modulation duty cycles. No proprietary software is required; all interface protocols are hardware-agnostic and support standard I²C or analog PWM control inputs.

Applications

• Medical Diagnostics: Capnography (CO₂ monitoring in anesthesia and critical care), respiratory alcohol screening (ethanol in exhaled breath), lung function testing (NO, CO detection), and anesthetic agent quantification
• Automotive & Transportation: On-board OBD-II compliant exhaust gas analysis (CO/NOₓ), ignition-interlock breathalyzers, cabin air quality sensors (VOC/humidity), and battery thermal runaway detection (HF, CO)
• HVAC & Building Automation: Demand-controlled ventilation (DCV) via CO₂ setpoint regulation, refrigerant leak detection (R134a, R1234yf), and indoor air quality (IAQ) monitors
• Industrial Safety & Environmental Monitoring: Fixed and portable combustible gas detectors (CH₄, H₂S), fumigation chamber verification (phosphine, sulfuryl fluoride), and semiconductor fab cleanroom monitoring (NH₃, HF)
• Research & Calibration: Reference source for FTIR spectrometer validation, NDIR sensor bench testing, and photoacoustic cell characterization

FAQ

What spectral range does the EMIRS emitter cover, and how is it characterized?
The EMIRS emits broadband infrared radiation from 2 µm to 16 µm, with spectral radiance profiles measured traceably against NIST-calibrated blackbody standards. Each production lot undergoes spectral verification using FTIR spectroradiometry.
Can the EMIRS be used in explosion-proof or intrinsically safe environments?
Yes—when paired with certified current-limiting drivers and housed in appropriate enclosures, the low-power, solid-state nature of the EMIRS supports ATEX/IECEx Zone 1 and Class I Div 2 integration.
Is window material selection critical for accuracy in gas sensing?
Absolutely. CaF₂ and BaF₂ offer superior transmission below 8 µm but degrade under humidity; sapphire provides mechanical and chemical resilience across all target gases; Ge maximizes long-wave sensitivity but requires anti-reflection coating for optimal throughput.
How does the EMIRS achieve chopper-free modulation?
Its MEMS thermal mass is engineered for sub-millisecond thermal time constants, allowing direct square-wave current driving at frequencies up to 100 Hz—sufficient for lock-in amplification without mechanical interruption.
Does Axetris provide calibration certificates or metrological traceability?
Axetris delivers factory-measured spectral radiance data with uncertainty budgets referenced to PTB/NPL traceable standards. Full calibration services—including system-level radiometric certification—are available through authorized metrology partners.