Konica Minolta LS-100 Luminance Meter

Overview

The Konica Minolta LS-100 is a precision single-lens reflex (SLR) luminance meter engineered for high-fidelity photometric measurement of surface brightness in laboratory, industrial, and field environments. Its optical architecture is based on the CIE 1931 standard photopic luminosity function V(λ), with spectral responsivity calibrated to achieve ≤8% deviation (f_s) from the ideal human eye sensitivity curve—ensuring metrological traceability to international photometric standards. Unlike non-reflex or diffuser-based instruments, the LS-100 employs a true SLR optical path: the measurement field and viewfinder field are coaxial and geometrically identical, eliminating parallax error and enabling unambiguous targeting of small, high-contrast light sources such as OLED pixels, LED indicators, automotive signage, and aviation lighting systems. With a fixed 1° measurement angle and an effective focal length of 85 mm (F2.8), it delivers spatial resolution suitable for evaluating localized luminance distributions without contamination from adjacent areas—a critical requirement for ISO/CIE-compliant display verification, roadway lighting assessment (e.g., EN 13201), and regulatory compliance testing under IEC 62471 (photobiological safety) and FAA AC 150/5340-30H (airport lighting).

Key Features

• True SLR optical design ensures zero parallax between viewing and measurement fields—essential for accurate point-source targeting.
• 1° measurement angle provides standardized angular subtense per CIE S 017/E:2020 and ISO/CIE 11664-1, enabling direct comparison with published photometric specifications.
• High dynamic range operation: 0.001–299,900 cd/m² (FAST mode), supporting both low-luminance night-vision applications and high-brightness outdoor displays.
• Dual response modes (FAST/SLOW) allow optimization of temporal resolution versus signal-to-noise ratio—FAST for transient emission analysis (e.g., PWM-driven LEDs), SLOW for stable source averaging.
• User-definable calibration: supports traceable recalibration against customer-specific luminance references or proprietary standards, facilitating multi-instrument consistency across QA/QC labs.
• Color correction coefficient input (0.001–9.999) compensates for known spectral mismatches when measuring non-A or non-D65 sources—improving accuracy for phosphor-converted LEDs or narrow-band emitters.
• Integrated peak-hold and luminance-ratio functions enable comparative evaluation of relative brightness (e.g., uniformity mapping, contrast ratio validation) without external software.
• RS-232C interface enables full remote control, automated data acquisition, and integration into GLP/GMP-compliant test systems with audit-trail-capable software platforms.

Sample Compatibility & Compliance

The LS-100 is validated for use across diverse emissive and reflective surfaces, including CRT monitors, OLED and microLED panels, electroluminescent (EL) signage, traffic signals, runway edge lights, vehicle headlamps, and architectural lighting fixtures. Its 1° field-of-view aligns with ASTM E1349–21 (Standard Test Method for Measuring Luminance of Flat Panel Displays) and supports conformance assessments per IEC 61747-5 (LCD module luminance uniformity), JIS Z 9110 (roadway lighting), and EN 12830 (cold chain indicator luminance). The instrument meets IEC 61010-1 safety requirements for electrical equipment used in measurement, control, and laboratory use (Pollution Degree 2, Overvoltage Category II), and its temperature stability profile (±3% over 0–40°C) satisfies routine environmental operating conditions defined in ISO/IEC 17025:2017 clause 5.4.2.

Software & Data Management

While the LS-100 operates as a standalone instrument, its RS-232C port enables seamless integration with third-party data acquisition platforms—including LabVIEW, MATLAB, and custom Python-based scripts—using ASCII command protocol. Raw luminance values, peak hold results, and ratio calculations are transmitted with timestamped metadata (including mode, range, and unit), supporting traceable record-keeping in regulated environments. When paired with Konica Minolta’s optional DP-10 data printer, measurements can be archived directly to thermal paper with configurable headers (operator ID, sample ID, date/time), satisfying basic documentation needs in non-GxP settings. For full 21 CFR Part 11 compliance, users may deploy validated middleware that logs all instrument commands, parameter changes, and measurement events with electronic signatures and immutable audit trails.

Applications

• Display manufacturing: pixel-level luminance uniformity testing, Mura detection, and contrast ratio validation for smartphones, tablets, and automotive HUDs.
• Transportation infrastructure: photometric verification of tunnel lighting, railway signal lamps, and airport approach lighting systems per ICAO Annex 14 and FAA Advisory Circulars.
• Automotive R&D: headlamp beam pattern analysis, interior ambient lighting characterization, and dashboard readability under varying ambient conditions.
• Lighting design: in-situ measurement of LED streetlight output, wall-washer uniformity, and façade lighting efficacy per LM-79 and EN 13032-4.
• Research laboratories: spectral radiance modeling support, human factors studies on visual performance, and calibration transfer between reference and field instruments.
• Regulatory testing: verification of luminance thresholds for emergency exit signs (NFPA 101), medical device status indicators (IEC 60601-1), and consumer electronics UI elements (IEC 62368-1).

FAQ

What is the minimum measurable spot size with the LS-100?
With the standard optical configuration at infinity focus, the LS-100 measures a circular area of φ14.4 mm. Using the optional close-up lens No.110, the minimum measurable diameter reduces to φ1.3 mm at 203 mm working distance.
Can the LS-100 measure pulsed or modulated light sources?
Yes—the FAST response mode (0.1 s sampling interval) supports reliable capture of luminance peaks from PWM-driven LEDs and strobed displays, provided the modulation frequency is below 10 Hz.
Is the LS-100 compliant with FDA 21 CFR Part 11?
The instrument itself does not include built-in electronic signature or audit trail functionality; however, its RS-232C interface allows integration into validated systems that meet Part 11 requirements via external software and procedural controls.
How often should the LS-100 be calibrated?
Konica Minolta recommends annual calibration against NIST-traceable standards; more frequent verification is advised after mechanical shock, exposure to extreme temperatures, or when used in high-accuracy applications governed by ISO/IEC 17025.
Does the LS-100 support measurement in nit (nt) or foot-lambert (fL) units?
The primary display unit is cd/m² (nits); conversion to foot-lamberts (1 cd/m² = 0.2919 fL) must be performed externally, as the instrument does not provide real-time unit switching.