TES-1335 Illuminance Meter by TES Electrical Electronic Corp.

Overview

The TES-1335 Illuminance Meter is a precision handheld photometric instrument engineered for reliable, repeatable measurement of ambient illuminance in accordance with internationally recognized photobiological and lighting metrology standards. It operates on the principle of spectral-weighted photometric detection—utilizing a silicon photodiode coupled with a precision optical filter that closely matches the CIE 1931 photopic luminosity function V(λ). This ensures high fidelity to human visual sensitivity across the visible spectrum (380–780 nm), with a spectral mismatch index f”₁ < 6%, meeting the stringent requirements of CNS 5119 Class AA and aligning with IEC 60825-1 and CIE S 011/E:2003 for cosine angular response. Designed for field and laboratory use in lighting design validation, workplace illumination audits, museum conservation lighting assessment, and educational photometry applications, the TES-1335 delivers traceable measurements across six auto-ranging lux scales (up to 40,000 Lux) and equivalent foot-candle equivalents—enabling direct comparability with North American lighting specifications.

Key Features

• Real-time cosine-corrected illuminance measurement compliant with CIE S 011/E:2003, minimizing angular error at incidence angles up to ±75°
• Peak hold and min/max capture functions for transient light event analysis and dynamic environment characterization
• Relative mode for comparative illuminance evaluation—ideal for uniformity mapping and fixture performance benchmarking
• Dual display output: high-resolution 3¾-digit LCD with simultaneous analog bar graph (13.3 Hz refresh) for rapid trend visualization
• Auto power-off after 30 minutes of inactivity to conserve battery life; supports ~400 hours of continuous operation on standard AAA cells
• Integrated overload protection with clear “OL” indication and automatic range switching across nine programmable measurement spans
• Robust mechanical architecture: lightweight (320 g), ergonomic body with IP54-rated ingress protection against dust and splashing water

Sample Compatibility & Compliance

The TES-1335 is optimized for measuring steady-state and slowly varying broadband visible light sources—including incandescent, halogen, fluorescent, LED, and OLED emitters—within standard indoor and outdoor ambient conditions. Its spectral response has been validated against NIST-traceable tungsten-filament reference lamps (2856 K CCT) and conforms to CNS 5119 Class AA accuracy requirements for general-purpose illuminance meters. The instrument satisfies foundational metrological criteria outlined in ISO/CIE 19476:2014 (photometry—definitions and units) and supports compliance workflows aligned with occupational health standards such as OSHA 1910.141 (lighting in workplaces) and EN 12464-1:2021 (lighting of work places). While not certified for GLP or FDA 21 CFR Part 11 environments, its stable analog-to-digital conversion architecture and documented calibration traceability make it suitable for quality control documentation under internal SOPs.

Software & Data Management

The TES-1335 operates as a standalone, self-contained measurement system with no embedded data logging or PC interface. All recorded values—including peak, min, max, and relative delta—are retained in volatile memory only during active measurement sessions. For archival or reporting purposes, users must manually transcribe readings or integrate the meter into external workflows using third-party digital loggers (e.g., via analog voltage output adapters, where available). No proprietary software, drivers, or cloud connectivity are provided. However, its consistent output formatting and stable analog bar-graph behavior enable straightforward integration into custom LabVIEW, Python, or MATLAB acquisition scripts when paired with compatible DAQ hardware. Calibration certificates (optional upon request) include full uncertainty budgets per ISO/IEC 17025 guidelines.

Applications

• Architectural lighting verification and daylight harvesting system commissioning
• OSHA-compliant workplace illumination surveys (e.g., manufacturing floors, laboratories, warehouses)
• Museum and gallery lighting audits to ensure artifact-safe illuminance levels (<50 Lux for sensitive pigments)
• Educational photometry labs for teaching V(λ) matching principles and inverse-square law validation
• LED product development support—relative output consistency checks across production batches
• Green building certification support (LEED EQ Credit 8.1, BREEAM HEA 3)

FAQ

What calibration standard is used for factory verification?
The TES-1335 is calibrated against a NIST-traceable 2856 K tungsten standard lamp in accordance with ISO/CIE 19476:2014 and CNS 5119.
Does the instrument support data export or USB connectivity?
No. The TES-1335 is an analog-digital hybrid meter without serial, Bluetooth, or USB interfaces. Data recording requires manual entry or external DAQ integration.
Is the cosine correction physically integrated or software-based?
Cosine correction is achieved via a precision-molded diffuser lens mounted directly over the silicon photodiode—ensuring hardware-level angular response compliance per CIE S 011/E:2003.
Can it measure pulsed or high-frequency modulated LED lighting accurately?
Due to its 1.3 Hz digital sampling rate and lack of high-speed photodetector bandwidth specification, it is not recommended for flicker analysis or PWM-driven sources above 20 Hz.
What is the recalibration interval recommendation?
Annual recalibration is advised for applications requiring CNS 5119 Class AA conformance; biennial verification suffices for routine industrial monitoring under stable environmental conditions.