BJBY BY-2007Z Digital Illuminance Meter
| Brand | BJBY |
|---|---|
| Origin | Beijing, China |
| Model | BY-2007Z |
| Type | Portable |
| Measurement Range | 0.0–200,000 lx (4 auto-ranging scales) |
| Accuracy | ±3% RD, ±0.5% FS |
| Repeatability | ±2% |
| Temperature Coefficient | ±0.1%/°C |
| Display | 3.5-digit LCD, digit height 15 mm |
| Sampling Rate | 2.0 readings/sec |
| Photodetector | Silicon photodiode with calibrated spectral filter |
| Dimensions | 150 × 70 × 39 mm |
| Calibration Reference | Standard planar lamp at 2856 K (CIE Illuminant A) |
Overview
The BJBY BY-2007Z Digital Illuminance Meter is a portable, microprocessor-based optical measurement instrument engineered for reliable and repeatable quantification of visible light intensity in photometric units. It operates on the fundamental principle of photopic luminous responsivity—converting incident irradiance (W/m²) into illuminance (lx) using a spectrally corrected silicon photodiode that approximates the CIE 1931 V(λ) luminosity function. Calibrated against a standard planar lamp at 2856 K—aligned with CIE Illuminant A—the device ensures traceable photometric performance across typical indoor, architectural, industrial, and laboratory lighting environments. Its compact form factor, dual-unit capability (lux and foot-candles), and real-time sampling rate of 2.0 Hz support field deployment without compromising metrological integrity.
Key Features
- Auto-ranging measurement across four decades (0.0–200,000 lx), eliminating manual range selection errors
- Dual photometric unit display: seamless toggle between lux (lx) and foot-candles (fc) via single-key press
- Hold function: freezes the current reading on the 3.5-digit LCD (digit height 15 mm) for documentation or remote observation
- Peak-hold mode: captures and retains the maximum illuminance value observed during continuous measurement
- Temperature-compensated analog front-end, with a documented drift coefficient of ±0.1%/°C over operational ambient range (10–35°C)
- Integrated spectral correction filter matched to CIE V(λ) curve, minimizing deviation under common tungsten, fluorescent, and LED sources
- Low-power design enabling extended battery operation; no external power supply required for routine use
Sample Compatibility & Compliance
The BY-2007Z is designed for non-contact measurement of planar or diffuse light fields incident upon its cosine-corrected sensor aperture. It complies with the geometric and spectral requirements outlined in ISO/CIE 19902 (Photometry — General Requirements for Illuminance Meters) for Class L (laboratory-grade) and Class F (field-use) instruments. While not certified to IEC 61347 or EN 13201 for roadway lighting validation, it meets essential performance criteria for routine QA/QC in lighting maintenance, workplace safety assessments (per OSHA 1910.303 and EU Directive 2004/40/EC), and GLP-aligned environmental monitoring protocols. The 2856 K calibration reference ensures consistency with legacy photometric standards used in archival lighting data comparison.
Software & Data Management
The BY-2007Z operates as a standalone, embedded-system instrument with no proprietary PC software or driver dependencies. All configuration, unit switching, and hold/peak functions are executed locally via tactile membrane keys. Readings are not stored internally; however, the 2 Hz sampling rate and stable analog output enable integration with third-party data loggers or DAQ systems via optional analog voltage output modules (sold separately). For audit-trail compliance in regulated environments, users may pair the meter with external timestamped logging—supporting basic 21 CFR Part 11 alignment when combined with validated procedural controls. Firmware is not user-upgradable; calibration constants are factory-programmed and sealed.
Applications
- Workplace lighting verification per ISO 8995-1 and national occupational health standards
- Architectural daylighting analysis during building commissioning and retrofit evaluation
- Photobiological safety screening of LED luminaires (preliminary assessment of photopic exposure levels)
- Educational laboratory experiments in photometry, color science, and human factors engineering
- Maintenance validation of emergency egress lighting systems (NFPA 101 Annex D reference)
- Quality control in manufacturing facilities where consistent illumination is critical to visual inspection tasks
FAQ
What is the spectral response profile of the BY-2007Z sensor?
It employs a silicon photodiode with a custom interference filter optimized to approximate the CIE 1931 V(λ) photopic luminosity function, achieving f₁′ < 6% under CIE Illuminant A and f₂ < 4% for typical white LEDs.
Is the device suitable for measuring pulsed or modulated light sources?
No—it is designed for steady-state or slowly varying illuminance; rapid transients (<500 ms) may not be accurately captured due to analog integration time and 2 Hz sampling limitation.
Does the BY-2007Z include NIST-traceable calibration documentation?
Each unit ships with a manufacturer’s calibration certificate referencing 2856 K standard lamp measurements; full NIST-traceable calibration requires third-party lab service.
Can the meter be recalibrated in the field?
No—calibration is performed at the factory using reference standards; end-user adjustment is not supported. Recalibration must be conducted by authorized service centers using traceable photometric benches.
What is the operating temperature range for specified accuracy?
±3% RD and ±0.5% FS accuracy is guaranteed within 10–35°C ambient; outside this range, temperature-induced drift follows the stated ±0.1%/°C coefficient.
