Apogee SU-100 Ultraviolet Radiation Sensor

Overview

The Apogee SU-100 Ultraviolet Radiation Sensor is a precision-calibrated, thermopile-based photodetector engineered for quantitative measurement of biologically and photochemically relevant ultraviolet (UV) irradiance across the 250–400 nm spectral band. Unlike silicon photodiodes requiring complex optical filtering and temperature compensation, the SU-100 employs a spectrally selective interference filter combined with a blackened thermopile detector to deliver inherently stable, broadband UV responsivity with minimal angular dependence. Its design adheres to the principles of actinometric radiometry—ensuring traceable, absolute measurements in both quantum (μmol·m⁻²·s⁻¹) and radiometric (W·m⁻²) units without user recalibration. The sensor is optimized for field-deployable applications where environmental robustness, long-term stability, and low thermal drift are critical—particularly under variable humidity, temperature cycling, or partial submersion.

Key Features

• Thermopile-based detection architecture ensures minimal spectral shift and negligible temperature coefficient (<0.05 %/°C) across the operating range
• Dome-shaped fused quartz diffuser provides Lambertian cosine response (±3% deviation up to 80° incidence angle) and prevents water pooling or dust accumulation
• Hermetically sealed, corrosion-resistant stainless-steel housing with IP68 rating—certified for continuous operation at depths up to 1 m in freshwater or saline environments
• Self-powered operation: no external voltage supply required; output signal is passive analog voltage (0–60 mV), compatible with most data loggers supporting millivolt input channels
• Digital output option available via integrated RS-485 interface (Modbus RTU protocol), enabling multi-sensor daisy-chaining and remote calibration verification
• Factory-calibrated traceable to NIST-standard UV sources; calibration certificate includes spectral responsivity curve and uncertainty budget per ISO/IEC 17025 requirements

Sample Compatibility & Compliance

The SU-100 is designed for direct irradiance measurement of natural solar UV and artificial UV sources—including low-pressure mercury lamps (254 nm), medium-pressure UV lamps (200–400 nm), UV-LED arrays, and excimer sources. It meets the geometric and spectral criteria defined in ASTM E2914–21 (Standard Practice for Measurement of Ultraviolet Irradiance) and aligns with ISO 17166:2019 (Erythemal UV reference spectra). While not intended for Class I laser safety measurements, its spectral rejection ratio (>10⁴) outside 250–400 nm satisfies IEC 62471 requirements for UV hazard assessment of general lighting equipment. The sensor housing material (316 stainless steel + fluorosilicone O-ring) complies with FDA 21 CFR 177.2600 for incidental food contact, supporting use in UV sterilization validation within GMP-regulated pharmaceutical water systems.

Software & Data Management

Apogee provides the free, cross-platform ApogeeConnect software for real-time visualization, batch logging, and unit conversion (μmol·m⁻²·s⁻¹ ↔ W·m⁻²) using embedded calibration coefficients. For enterprise integration, the SU-100’s Modbus-enabled variant supports direct ingestion into SCADA platforms (e.g., Ignition, Siemens Desigo) and LIMS systems compliant with ASTM E2500-22 (Verification and Validation of Computerized Systems in Pharmaceutical Manufacturing). All logged datasets include embedded metadata—timestamp, sensor serial number, firmware version, and environmental status flags—enabling full audit trail compliance per 21 CFR Part 11 when used with validated data acquisition hardware.

Applications

• Field monitoring of UV-B (280–315 nm) and UV-A (315–400 nm) components in ecological and atmospheric research, including ozone depletion studies and plant photomorphogenesis trials
• Validation of UV-C disinfection efficacy in HVAC ducts, surface treatment chambers, and point-of-use water purifiers per NSF/ANSI 55 and EPA UV Disinfection Guidance Manual protocols
• Calibration transfer standard for laboratory UV radiometers and spectroradiometers (e.g., as a secondary reference against calibrated deuterium lamps)
• Real-time dose monitoring during UV-curable resin processing in additive manufacturing and printed electronics fabrication
• Long-term degradation testing of polymers, coatings, and encapsulants per ISO 4892-3 (fluorescent UV exposure methods)

FAQ

Is the SU-100 suitable for continuous outdoor deployment over multiple years?

Yes—the thermopile detector exhibits <3% annual drift under typical ambient conditions; recalibration is recommended every 24 months for ISO/IEC 17025-compliant applications.
Can the sensor be submerged permanently in seawater?

It is rated IP68 for 1-meter depth up to 30 days; prolonged immersion requires periodic inspection of the O-ring integrity and replacement per Apogee’s maintenance schedule.
Does the sensor require temperature compensation during data acquisition?

No—its thermopile design and internal thermal mass minimize temperature-induced signal drift; however, ApogeeConnect software optionally applies NIST-traceable temperature correction if high-precision radiometric work is performed across >40°C gradients.
What is the maximum cable length achievable without signal attenuation?

With shielded twisted-pair cable and proper grounding, analog output remains stable up to 100 m; for RS-485 digital output, maximum daisy-chained distance is 1,200 m per Modbus specification.
How is calibration traceability documented?

Each unit ships with a NIST-traceable calibration certificate listing measurement uncertainty (k=2), spectral responsivity data, and compliance with ISO/IEC 17025:2017 Clause 6.2.5 (reference material characterization).