Radiant Imaging PM-NFMS Near-Field Goniophotometer - Pro-Lite ...

Radiant Imaging
PM-NFMS Near-Field
Goniophotometer for Luminaires
Pro-Lite Technology LLP
Tel: +44 (0) 1234 436110 info@pro-lite.co.uk www.pro-lite.co.uk

Near Field Goniophotometry
• Luminaires were traditionally measured using a
“far-field” goniophotometer – these require a
large dark room and are expensive
• CCD imaging photometers are now being used to
measure the near-field luminance
• Software scales the near-field luminance to farfield
luminous intensity which is then
manipulated into industry-standard file formats
(EULUMDAT, IESNA)
• Near-field goniophotometers are much less
expensive and require a fraction of the space to
operate

PM-NFMS System Overview
• A near-field goniophotometer for testing
luminaires
• Based upon a ProMetric CCD imaging
photometer / colorimeter with motorised
goniometer stage
• Motorised operation over 2π steradians
• Reports far-field luminous intensity versus
θ, φ (elevation, azimuth)
• Outputs standard files for lighting design
in conjunction with ProSource software

System Capability
• Data required:
– Far-field luminous intensity (candelas)
versus angle
• Data to be formatted as IESNA (.ies)
& EULUMDAT (.ldt) files – these are
the standards used by lighting
designers

ProMetric NFMS System
• The PM-NFMS goniophotometer
system comprises:
– Motorised goniometer stage – 3 sizes
– A ProMetric CCD imaging photometer /
colorimeter (e.g. PM-1200N-1)
• ProSource software to convert nearfield
luminance to far-field luminous
intensity readings and output
IES/LDT files

ProMetric CCD Imaging
Photometer

NFMS-0800 Goniometer Stage

What Can a ProMetric Imaging
Photometer Test
LED Arrays 1 Vehicle Front Lighting 2 Luminaires 3 Vehicle Rear Lighting 2
Signs
Flat Panel Displays Illumination Design Instrument Panels 4 Keyboards
Projectors
Image credits: (1) Ayrton; (2) Hella; (3) Waldman;
(4) Bentley; (5) Philips; (6) Lumileds
OLED Displays 5
Display Backlights 6
LED Video Screens

What Properties Do They
Measure
Type
Photometric
Colorimetric
Property
Luminance – Near Field
Illuminance – Far Field
Luminous Intensity – Far Field
CIE Chromaticity
Colour Temperature
Dominant Wavelength
Unit
L v (cd/m 2 )
E v (lux)
I v (cd)
Cx, Cy, u’, v’
CCT (Kelvin)
λ D (nm)

What is a CCD
• Lens images object onto the CCD array
• Each CCD element (pixel) records the flux
it receives, creating a “grey count”

NFMS-0800 Goniometer Stage

Luminaire Sizes
• NFMS-0400 compact frame:
– Recommend for samples up to 90 x 36cm,

Software Interface
• Following slides illustrate the user
interface
– PM-NFMS software which reports the
near-field luminance versus angle
– ProSource software which scales the
data to the far-field and outputs polar
intensity charts and IES/EULUMDAT
files