Cylindrical / Semi-cylindrical Illuminance Measurement

Field Esc and cylindrical illuminance measurement solution

Cylindrical / Semi-cylindrical Illuminance Measurement

Horizontal illuminance answers whether the ground is bright enough; semi-cylindrical illuminance Esc answers whether a person at that point can be recognized. CJJ 45 lists Esc for pedestrian and non-motorized lanes; JGJ/T 163 requires Esc for walkways, plazas and parks; GB/T 50034—2024 adds Esc to building lighting design. This solution centres on portable semi-/full-cylindrical meters—standards, selection, field layout and calibration—with LuxPartner for grid logging and reports.

Typical setup: LUX-100D-C for Esc (facial recognition, road/security) or LUX-100D-F for full cylindrical/spatial illuminance (architecture, museums), with tripod and spirit level at 1.5 m (or project height) and defined orientation. Methods follow GB/T 5700; meter performance per GB/T 39388 / CIE S 023; calibrate on an optical bench with the internal reference plane (~0.067×d) and stray-light baffles. In the field, LuxPartner on Android (Bluetooth) or Windows / Linux desktop (USB serial or Bluetooth) provides live readings, uniformity grids, integral and timed logging, PDF/text export, and session files shared across phone and PC. For plant photosynthesis use a PPFD probe—do not substitute cylindrical illuminance.

Key Features

Separate metrics: Eh / Esc / full cylindrical—do not accept with horizontal lux alone
Standards chain: CJJ 45, JGJ/T 163, GB/T 50034 limits + GB/T 5700 methods + GB/T 39388 characterization
Matched instruments: LUX-100D-C semi-cylindrical (0.01 lx–20 klx, ≤±4%) and LUX-100D-F full cylindrical
LuxPartner companion: Android app + Windows / Linux; live reading, uniformity/integral/logging, PDF reports
Connectivity: Bluetooth on phone; USB serial or Bluetooth on PC; session files across devices
Traceability and field workflow: optical-bench calibration; 1.5 m height and orientation in reports

Core Application Scenarios

Sidewalk and NMV lane acceptance

Measure Esc,min at 1.5 m on the centre line per CJJ 45, report with Eh and Ev for facial recognition and pedestrian security.

Plazas, parks and nightscape public spaces

Evaluate ground Eh and Esc at 1.5 m per JGJ/T 163 for walkways, courtyards and play areas.

Building outdoor public areas and spatial modeling

Use LUX-100D-C for GB/T 50034—2024 outdoor Esc minima; LUX-100D-F for architectural surround / museum modeling.

LuxPartner field grids and reports

Connect the meter with LuxPartner on Android / Windows / Linux for uniformity grids, integral or timed logging, PDF/text export, and session sharing between phone and PC.

FAQ

How does Esc differ from horizontal illuminance, and why measure it for acceptance?▾

Horizontal illuminance evaluates ground/task brightness; Esc averages on a vertical semi-cylinder and better reflects facial recognition and pedestrian security. CJJ 45, JGJ/T 163 and GB/T 50034—2024 list Esc separately—do not substitute horizontal lux.

Which instruments and software does this solution recommend?▾

Use LUX-100D-C for sidewalk/plaza Esc and LUX-100D-F for architectural surround. In the field, LuxPartner on Android (Bluetooth) or Windows / Linux (USB serial or Bluetooth) handles uniformity grids, integral/logging and PDF export.

What height and orientation should Esc field points use?▾

CJJ 45 often uses 1.5 m above pavement on the centre line; nightscape walkways/plazas commonly use 1.5 m. The semi-cylinder is oriented—follow the standard viewing direction, record it, level the tripod and avoid self-shadowing.

How is Esc meter traceability ensured?▾

Optical-bench calibration uses Esc=(2/π)·I/l² with distance to the internal reference plane (~0.067×diameter) and stray-light baffles. Expanded uncertainty is often about 1–1.3% (k=2), adequate for typical ±4% MPE transfer.

Measurable parameters

Semi-cylindrical illuminance Esc (lx)

Cylindrical (full) average illuminance (lx)

Horizontal illuminance Eh (with LUX-100D, lx)

Technical specifications

LUX-100D-C: semi-cylindrical receptor, 0.01–20 klx, ≤±4%, digital V(λ), Type-C
Effective reference plane ≈0.067×d from cylinder side (use for bench distance)
Field accessories: tripod, spirit level, 1/4″ screw mount
LuxPartner: Android (Bluetooth); Windows / Linux (USB serial or Bluetooth); uniformity / integral / logging / PDF reports