SSL Type C Goniophotometers

SSL Resource Photometers, Colorimeters & Spectroradiometers

SSL Resource offer a range of precision, laboratory-grade photometers, colorimeters and spectroradiometers that can be deployed as part of a goniophotometer system or can be used independently. A photometer provides a wide dynamic range measurement of illuminance in lux, luminous intensity in candelas, and of total luminous flux in lumens (computed as the 2π or 4π integral of directional luminous intensity). A tristimulus colorimeter doubles as a photometer but adds the capability to measure CIE chromaticity coordinates and correlated colour temperature in Kelvin. A spectroradiometer is generally used as a secondary sensor in a goniophotometer system due to a more limited dynamic range but adds the ability to measure radiometric (UV and IR) light levels, photon flux readings for assessing horticultural lighting and colour rendering metrics.

SSL LC-800.x Laboratory Photometer & Colorimeter – Brochure

The SSL LC-800.x is a precision, high speed photocurrent meter capable of accepting inputs from 1 to 4 sensors, with the “x” suffix denoting the number of channels chosen. The LC-800 can function both as a photometer when connected to a photopic sensor, or as a colorimeter when connected to three tristimulus XYZ response sensors. Please note that for the highest colorimetric accuracy, the LC-800 can be equipped with four tristimulus sensors, with the X (red) channel separated into XR (red) and XB (blue) channels. The LC-800 is compatible with both LH- and CH-series sensors. 

With a dynamic range of 9 decades, the LC-800 is capable of recording both high intensity and low intensity light levels without the need to move the sensor whilst maintaining the required far-field test conditions. In comparison, a spectroradiometer may need to be moved closer to the light source to avoid signal to noise errors with low powered lighting or moved further away to avoid saturating the sensor with a high-powered source.

With a sampling bandwidth of up to 200kHz, the LC-800 can also function as a sensitive flicker meter, with the ability to record stroboscopic visual measure (SVM) flicker at >2kHz. This bandwidth also allows a goniophotometer system equipped with an LC-800 to measure “on the fly”, resulting in shorter scan times compared with more traditional “stop & go” type motion.

SSL L-40 Laboratory Photometer – Brochure

The SSL L-40 is a more economical alternative to the LC-800 for those who don’t need such a wide dynamic range. The L-40 is compatible with LH-series photopic sensors and with a sampling bandwidth of up to 100kHz, both photometric and flicker measurements are possible. The L-40 is available in two versions, with both the low light level and high light level versions (L-40.2) providing a dynamic range of over 4 decades.

SSL C-400 Laboratory Colorimeter – Brochure

The SSL C-400 is a three-channel colorimeter version of the L-40 photometer. The L-400 is compatible with the CH-series tristimulus sensors, and with a sampling bandwidth of up to 15kHz, photometric, colorimetric and flicker measurements are possible. The L-400 is available both as a low light level and as a high light level model (L-400.2) and provide a dynamic range of over 4 decades.

SSL S-680 Laboratory Spectroradiometer – Brochure

The SSL S-680 is a compact, CCD array spectrometer that is usually chosen as a secondary sensor in a goniophotometer system given the more limited dynamic range it possesses than the LC-800 photometer. It provides the ability to measure radiometric (UV and IR irradiance) values as well as photon flux readings for assessing horticultural lighting and colour rendering metrics for architectural lighting. The S-680 is available in four versions that cover different ranges in the 250-1050nm wavelength range.

SSL S-80 Portable Spectroradiometer – Brochure

The SSL S-80 “SPEKTRI” is a portable array spectroradiometer that can be used as a secondary sensor as part of a goniophotometer system, or separately as a versatile light meter. The S-80 provides for spectral irradiance measurements from which photometric and colorimetric parameters are computed. As a secondary sensor in a goniophotometer system, the S-80 provides the ability to measure radiometric (UV and IR irradiance) values as well as photon flux readings for assessing horticultural lighting and colour rendering metrics for architectural lighting.

For field use, the S-80 is controlled via Bluetooth from your Android smart phone, while for laboratory applications, communication is via USB to a PC (Windows software is available as an extra cost option).

The S-80 is sold in one of five application-specific configurations:

• The S-80.PAR is intended for use with horticultural lighting.
• The S-80.Ee is configured for medical and dental lighting applications.
• The S-80.ColorLux is designed for use with general lighting products and includes a flicker utility.
• The S-80.Lv is equipped with a luminance probe and is suitable for display and automotive applications.
• The S-80.Lab is the only model that isn’t battery operated and comes as standard with PC software for laboratory use.

SSL Resource Photometric & Colorimetric Sensors

When configuring your SSL goniophotometer system, you can choose from a range of photometric, colorimetric and radiometric response sensor heads. Each is designed for use with an SSL photocurrent meter (see: Meters tab). Note that the range and resolution of a particular sensor is influenced by the companion meter it is paired with.

A photopic response sensor provides a wide dynamic range measurement of illuminance in lux, luminous intensity in candelas, and of total luminous flux in lumens (computed as the 2π or 4π integral of directional luminous intensity). A tristimulus colorimetric sensor doubles as a photometer but adds the capability to measure CIE chromaticity coordinates and correlated colour temperature in Kelvin. A radiometric sensor provides for a near wavelength independent response over a defined spectral range for the measurement of infrared irradiance in Watts per square meter. A further range of radiometric sensors is designed for measuring the photosynthetic photon flux density (PPFD) from horticultural lighting products.

SSL LH Photopic Response Sensors

The LH photopic response sensors are silicon detectors combined with a filter that imparts a spectral match to the CIE V(λ) photopic observer function and calibrated for measurements of illuminance in lux. When used to measure axial luminous intensity as part of a goniophotometer system, a baffle tube is supplied to screen stray light. When measuring extended sources, a cosine diffuser is available for the 6.7mm sensor to properly scale the off-axis illuminance. With an f1′ of 3%, most sensors in the LH family satisfy the spectral matching requirements of DIN class A.

SSL CH Tristimulus Colorimetric Response Sensors

The CH tristimulus response sensors comprise three or four collocated silicon sensors each matched to the CIE 1931 xyz tristimulus color matching functions. These detectors are calibrated for illuminance measurements in lux and add the capability to measure CIE chromaticity coordinates and correlated colour temperature (CCT) in Kelvin. The four channel sensors separate the CIE X tristimulus response into X-red and X-blue channels for improved colorimetric accuracy.

SSL LH PPFD Radiometric Response Sensors

The LH PPFD radiometric response sensors are silicon detectors combined with a radiometric filter that is calibrated for the measurement of photosynthetic photon flux density in units of μmols/m².s. These detectors are used to assess the performance of horticultural lighting products.

SSL LH Irradiance Sensors

The LH irradiance sensors are silicon detectors combined with a radiometric filter that is calibrated for the measurement of irradiance in units of W/m². These detectors are used to assess the performance of infrared lighting products.

SSL LH UV Irradiance Sensors

The LH UV irradiance sensors are silicon detectors combined with a radiometric filter that is calibrated for the measurement of irradiance in units of W/m². These detectors are used to assess the performance of UV lighting products with both narrow and broadband UVA and UVC sensors available.

SSL Resource Goniophotometer Software

Your SSL Resource goniophotometer system will be supplied with Windows software specific to the motion type(s) you have chosen, either type C or type A/B. You can either provide your own PC, or if you prefer, Pro-Lite will supply a pre-configured computer as part of the goniophotometer system.

Type C Goniophotometer Measurement Parameters

The type C goniophotometer system software will report the following parameters when used with the SSL LC-800 photometer:

• Luminous intensity (candelas)
• Illuminance (lux)
• Total luminous flux (lumens)
• With optional software add-ons
  • Flicker metrics
    • Flicker index
    • Percent Flicker (%)
    • Flicker Frequency (Hz)
    • Stroboscopic Visual Measure
    • Short Term Perceptibility Light Modulation
  • EPREL Software Module, this allows you to generate EPREL database reports as well as the data files required for the EPREL database upload in a goniophotometer measurement.
• Effective luminous intensity (for flashing light sources)
• With optional tristimulus colorimeter sensors:
  • CIE 1931 & 1976 chromaticity coordinates (xy, u’v’)
  • Correlated colour temperature (CCT, Kelvin)
  • Dominant wavelength & spectral purity
• With optional spectroradiometer:
  • Spectral power distribution (250-1050nm, depending upon spectrometer model chosen)
  • Spectral irradiance (W/m².nm)
  • Spectral radiant intensity (W/sr.nm)
  • CIE 1931 & 1976 chromaticity coordinates (xy, u’v’)
  • Correlated colour temperature (CCT, Kelvin)
  • Dominant wavelength & spectral purity
  • Colour rendering (CIE 13.3 Ra & R1-14; IES TM-30-18 Rf & Rg)
  • Photosynthetic photon flux density, PPFD (μmols/m².s)
• With compatible AC/DC power meters & power supplies:
  • Electrical parameters (Amps, Volts)
  • Power consumption (Watts)
  • Luminous efficacy (lumens per Watt)
  • Power factor

The type C goniophotometer software provides a multitude of charting options. These include polar intensity diagrams for selected C-planes, dynamic cone illuminance diagrams, BUG (back/up/glare) diagrams and spatial illuminance modelling tools. For systems equipped with a colorimeter, the spatial colour uniformity (SDCM) is presented in a CIE chromaticity diagram. For systems equipped with a spectroradiometer, TM-30 colour rendering vector charts are produced. 

The luminous intensity values can be exported as delimited text (XML format) or as standardised photometric data files in IES, LDT or TM-30 formats. A built-in convertor allows for files to be converted between the different formats, while an LDT editor allows for manipulation of files without recourse to third party software. For luminaires that shine up and down, the software has a utility for combining both the upwards and downwards facing measurement data into a single file. A beam symmetrisation tool simplifies the measurement of rotationally symmetric luminaires.

Type A/B Goniophotometer Measurement Parameters

SSL Resource AUTO 100 (type B) and AUTO 1000 (type A) goniophotometers, as well as the natively type C LAMP 30 or LUMI series model configured for type B motion (or supplied with a type C to type B conversion kit) are supplied with supplementary software that features pass/fail type reporting to various vehicle, transportation and avionics standards, including ICAO, CAP 437, ECE, FVMSS108, FAA and so on. Road illumination can be rendered as a “bird’s eye” plan view or as a 3D projection on the road surface in greyscale combined with a traversal plane at 50m in colour. Isolux charts can also be generated to render zones of constant illuminance.

SSL Resource Goniophotometer Options

The following options are available for your SSL Resource goniophotometer system.

Light Meter Options

• Photometers: choose from the standard L-40 photometer or upgrade to the high-performance, 4-channel LC-800 that features a faster sampling rate, 9-decade dynamic range and the ability to perform measurements “on the fly”, reducing overall goniometer scan times.
• Colorimeters: if you need to measure CCT and chromaticity as a function of angle, choose the L-400 colorimeter, or add a tristimulus sensor to the 4-channel LC-800 photocurrent meter.
• Spectroradiometers: the S-680 is usually chosen as a secondary sensor in a goniophotometer system given the more limited dynamic range it possesses than the LC-800 photometer. It adds the ability to measure radiometric (UV and IR irradiance) values as well as photon flux readings for assessing horticultural lighting and colour rendering metrics for architectural lighting.

Compliance with CIE S025 & IES LM-79-19: Burn Position Correction

Standards such as CIE S025 and IES LM-79-18 require that the device under test be mounted in its design orientation and not be tilted or rotated with respect to gravity during a goniometric scan. All SSL type C motion goniophotometers except for the DECO 27 mount the device under test (DUT) in a vertical plane, such that the optical axis is horizontal. While the lamp does not tilt with respect to gravity during a scan, it will rotate about its own horizontal (azimuth) axis. Given that most architectural light fittings tend to be ceiling mounted and shine vertically down, it can be desirable to mount the DUT in the same (vertical, base-up) orientation.

To this end, we offer the SSL-ALI Absolute Lumen Integrator. This accessory attaches to the C-plane motor of the host goniometer system to mount the DUT in a vertical-down (base up) orientation. It is designed to mount architectural or decorative light fittings with relatively small luminous areas. In the event that you cannot mount the DUT in its intended orientation, we offer the SSL-BPC Burn Position Corrector accessory (shown right fitted to a LUMI 90). This device also attaches to the C-plane motor of the host goniometer and allows the operator to measure the difference in light output from the DUT in its design orientation compared to that in which it is mounted onto the goniophotometer. The goniophotometer software will then compute a correction factor which it will then automatically apply to subsequent measurements of that product.

The DECO 27 goniophotometer is also a type C motion model, however unlike the other models, the DUT is mounted in a vertical-down orientation. As such, the DECO model fully complies with the fixed burn position requirements of CIE S025 and IES LM79-19 without recourse to either the ALI or BPC accessory options.

Alignment Camera

The SSL IMG-2 is a 2.3 Megapixel USB 3.0 auxiliary alignment camera that is available as an option in SSL LUMI-series goniophotometers. In addition to the two, standard motorised axes, LUMI systems can be configured with a motorised vertical arm and camera that automates the positioning of the device under test about the goniometer’s centre of rotation. The camera can also automatically determine the size of the luminous area of the light source. Lastly, you can add a motorised sample holder, making the job of mounting your sample to the goniometer frame much simpler and quicker.

Packaging Options

• The SSL-RACK-1 is a separate equipment rack for C-1 series goniophotometer systems having an 8U space for all devices including goniophotometer controller and DC / AC power sources.
• The SSL-RACK-2 is a larger 19-inch 8U equipment rack that houses the goniophotometer controller and auxiliary power electronics together with a tabletop for mounting a PC and flat panel display. The unit is mounted on lockable castors.
• The SSL GONIO-NEST is portable dark enclosure for the goniophotometer that doubles as a rugged, reusable shipping container. The goniometer station and accessories are transported inside SSL GONIO-NEST which opens up to create a semi-dark enclosure.

Stray Light Control

Stray light should be minimised in all photometric laboratories. All SSL goniophotometer systems are supplied with a photometer and sensor that is equipped with a stray light tube. This limits the field-of-view of the sensor to just beyond the lit area of the DUT as it moves on the goniometer frame. To further reduce stray light errors, we offer the SSL BLACK low reflectance fabric material that can be placed directly behind the goniophotometer. The combination of stray light tube and black material behind the goniometer frame allows the use of overhead lighting during goniometric scans.

Sample Holders

A wide range of standard sample holders is available to simplify the mounting of your lighting product to the SSL goniometer frame. Choose from holders for linear fittings, panel lights, downlighters, streetlights, recessed fittings and flood/high bay lights. Customised holders are also available upon request.

Motion Conversion Kits

SSL LAMP 30 as well as LUMI series type C goniophotometers can be fitted with an accessory kit to convert their motion to type B for the measurement of directional light sources. The user-installed kit includes mechanical adaptors and a type B software bolt-on. Similarly, a LAMP 30.B or LUMI series goniometer that is factory configured for type B motion can be converted to type C motion with an accessory kit. The type B to type A kit is shown in the image to the right.

Computer

The SSL-PC option is a Windows computer that is supplied preconfigured and with software preinstalled for the goniophotometer system. This simplifies the procurement of a suitable computer, saving time and helping to ensure that your goniometer system is up and running as quickly as possible.

Resources

Datasheets & Brochures

• SSL Goniophotometer Range Catalogue – Sept 2024
• SSL Goniophotometer Comparison Guide
• SSL LAMP 30 Goniophotometer Datasheet
• SSL LAMP 200 Goniophotometer Datasheet
• SSL LEDI 70 Goniophotometer Datasheet
• SSL UNI 200 Goniophotometer Datasheet
• SSL LUMI Series Goniophotometer Datasheet
• SSL DECO 27 Goniophotometer Datasheet
• SSL Photometer & Colorimeter Brochure
• SSL SPEKTRI-80 Spectroradiometer Brochure
• SSL S-680 Spectroradiometer Datasheet
• SSL EPREL Software Addon 

Technical Information

• The Science of Goniophotometry: this guide explains the science of goniophotometry, including the IES motion types (A, B & C), what motion type to use when testing different types of lighting product and the importance of making measurements in the photometric far-field.
• Photometer or Spectrometer: this technical note explains the pros and cons of configuring your goniophotometer system with either a photometer, a colorimeter or a spectroradiometer.
• Burn Position Correction & Compliance with CIE S025: this technical note explains the importance of maintaining the burn position of the device under test and how you can conform to the burn position requirements stated in CIE S025.
• Determination of the Photometric Far-Field Distance: this technical note explains the importance of performing goniometric measurements in the far-field and guides you on how to calculate this distance for your luminaire type.

Videos

• Video presentation of SSL Resource goniophotometers