LS-100/LS-110 Luminance Meters

Hand-held and light-weight precision Luminance Meter

High precision Luminance-Meter with small angle

The spot luminance meters LS-100 and LS-110, categorized in the upper range of the DIN quality class B, are among the best hand meters on the market. The SLR (single lens reflex) optical system allows precise targeting and ensures that the viewfinder shows the exact area to be measured, even at very short distances. This makes even precise focussing very easy. In addition to the measurement field and the measurement environment, the viewfinder also shows the measured luminance value. The pistol grip makes handling of the unit very secure. We have given special attention to minimize flare and to give precise V(λ) correlation (CIE relative photopic luminosity curve). With the help of a close-up lens, areas as small as 0.4mm diameter can be measured.

Areas of application

Light sources of all types can be measured with the LS, for example signal, traffic lights, airport lighting, lamps, LED's, picture tubes, etc., just about anything that emits light. Now you can, for example, guarantee minimum brightness, exchange lamps that are too dark early enough, build quality assurance into the production of lamps, or check indirectly illuminated objects like movie screens.

Background knowledge (LS-100)

The unit of illumination L equals candelas per square metre (cd/m2), and within this is also the source of this measurement, namely the light strength I emitted per surface area unit A in the angle ε :

L= I/(A cos(ε))

Basically, luminance specifies the brightness of a luminous surface and/or a light source. The sun has an luminance of about 1 billion cd/m2, fluorescent lamps about 10,000 cd/m2. In some countries the unit foot lambert (ftl) is also used to express illuminance, which the LS can display if required. 1 ftl = (1/π cd/ft2 = 3,426 cd/m2
With its 1° angle of measurement, the LS-100 represents the standard spot luminance meter. Its measurement range starts at 0.001 cd/m2 and is therefore able to meter extremely dark surfaces. With the large 9° field of view and the measured value displayed on an LCD in the viewfinder, the object of measurement can be controlled at all times without taking the LS-100 from your eye. A second LCD display on the exterior of the meter, plus a tripod screw port, allows the user to take measurements without looking through the viewfinder. A neutral density eyepiece filter is included to allow the user to measure strong light sources using the viewfinder.

Besides the measurement of absolute luminance, the LS can also display relative luminance as a percentage of a defined standard (target). With this function, the brightness distribution on large surfaces such as monitors can be rapidly ascertained. The peak luminance value can also be displayed on command, useful when measuring flickering light sources such as fluorescents.

In order to further improve the already negligible deviation from the targets of the CIE relative photopic luminosity curve for certain light sources, the LS-100 offers the option of user-calibration.

Background knowledge (LS-110)

The unit of illumination L equals candelas per square metre (cd/m2), and within this is also the source of this measurement, namely the light strength I emitted per surface area unit A in the angle ε :

L= I/(A cos(ε))

Basically, luminance specifies the brightness of a luminous surface and/or a light source.The sun has an luminance of about 1 billion cd/m2, fluorescent lamps about 10,000 cd/m2. In some countries the unit foot lambert (ftl) is also used to express illuminance, which the LS can display if required. 1 ftl = (1/π cd/ft2 = 3,426 cd/m2
The narrow angle of measurement of only 1/3&deg ensures the LS-110 is perfect for very small luminous surfaces and/or measurements in small steradians. With the help of the close-up lens VA-110, areas as small as 0.4 mm diameter can be measured. The measurement range is very large at 0.01 to 999,900 cd/m2 and covers a wide range of uses. All other features and technical specifications correspond to those of the LS-100.

LS-100

Product Overview

• Relative spectral response
  For the measurement of luminance, ideally the relative spectral response of the meter should perfectly match the sensitivity of the human eye for photopic vision, as represented by the CIE spectral luminous efficiency V(λ).

Principal Applications

• Measurement of the luminance of CRTs, LED, and ELs.
• Measurement of road and tunnel brightness
• Measurement of rail-system signals
• Measurement of road and airport signals
• Measurement of illumination and outdoor signs
• Measurement of illumination equipment and devices
• Research and measurement testing
• Measurement of device brightness

Main Features

• SLR (single-lens-reflex) optical system
  The LS-100's single-lens-reflex design ensures that there will be no deviation between the actual measurement area and the area indicated in the viewfinder. Eliminating the effect of illumination outside the measurement range, this flareless optical system ensures accurate measurement of only the target area.
• Spot measurement for small target areas
  With acceptance angles of 1° and 1/3° respectively, the LS-100 and LS-110 are ideal for measuring the luminance of small specimens. Furthermore, a close-up lens (sold separately) can be used to achieve a 1.3-mm measurement diameter for the LS-100 and a 0.4-mm measurement diameter for the LS-110.
• User calibration and color-correction functions for wide ranging support
  With a user calibration function allowing recalibration to any standard luminance that you select and a color-correction input function for correction of indication differences for specific light sources, multiple luminance meters can be used without error for extremely detailed luminance control.
• Luminance ratio and peak value measurement
  Based on the particular application, measurement values can be set to instantaneous luminance, peak luminance, and luminance ratio.
• Two-way RS-232C communication
  Featuring an RS-232C interface as standard, this luminance meter can connect with a PC to send measurement data and receive control signals.
• Lightweight, compact, and powered by a single 9V battery

LS-110

Features

Highly-portable, handheld design capable of measurements in a wide range of luminance conditions. Flareless SLR (single-lens-reflex) optical system for high-accuracy measurements. Acceptance angle of 1/3° supports measurement of small target areas.

Applications

Measurement of the luminance of CRTs, LED, and ELs.
Measurement of road and tunnel brightness
Measurement of railway system signals
Measurement of road and airport signals
Measurement of illumination and outdoor signs

Principal Specifications

Specifications are subject to change without notice.