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Equipment for Quality Control and R&D+i


A new generation of road marking retroreflectometer. It´s based on the latest technological developments and with modern design and materials. Very easy to calibrate and operate. RL and Qd retroreflectometer measurements.

LTL3500 is part of a new generation of DELTA retroreflectometer instruments for measuring retroreflection of road markings. The instrument is based on the latest technological developments
and with modern design and materials. LTL3500 is, like all other DELTA instruments, very easy to calibrate and operate, we like to say: “very user-friendly”. And the instrument is of course robust
and long lasting – like our earlier generations of road marking retroreflectometers – and on top of this small in size and light in weight

RL and Qd retroreflectometer measurements

The LTL3500 model is supporting not only night visibility (RL), but also daytime visibility (Qd) according to European and US standards. Where RL is a measure of the visibility of the nighttime retroreflected light, the Qd is a measure of the daytime visibility under diffuse illumination during daytime. In particular performance of markings at nighttime is a very important factor in ensuring safe driving conditions besides being a key parameter in making automated vehicles recognize the markings allowing good navigation abilities. Only measurement with a retroreflectometer like LTL3500 is able to tell if a marking performs according to standards

LTL3500 measures daytime visibility and nighttime visibility under dry and wet conditions as well as continuous wetting.

LTL3500 measures RL from 0 to 4.000 mcd/lx/sqm and Qd from 0 to 318 mcd/lx/sqm.


LTL3500 measures all types of road markings at a simulated distance of 30 m with high accuracy. The instrument operates with a reproducibility of +/- 5 % and a repeatability of +/- 2 %. The LTL3500 has a RL profile capacity of 15 mm.

Measurement of color coordinates (x,y)

LTL3500 measures nighttime retroreflected color – CIE chromaticity – for white and yellow markings according to EN1436 and ASTM D6628. Measuring color coordinates tells for example if yellow markings are seen as yellow at night as intended or they are viewed as white. .

GNSS location coordinates

The instrument can be offered with GNSS location coordinates drawing on 4 satellite systems: GPS, Galileo, GLONASS and BeiDou. GNSS will under almost all measurement conditions provide sufficient satellite connections to establish correct locations.

User friendly and easy to operate

LTL3500 is a very user-friendly and easy to operate instrument. The instrument is offered with many support features like: Extractable handle, GNSS, nighttime reflected color measurement, macro camera, overhead camera, orientation, air and marking temperature, relative humidity, road icon ID and external printer.

LTL3500 is suitable for carrying out full measurement programs and can store measurement related data and photo documentation together with the measurements. Still, LTL3500 is easy to operate and transport due to low weight, small size and extractable handle.

Measurement data can be transferred to Excel for storage and processing and to Google Earth for location visualization using GNSS. Measurement data can be linked to a User ID, a Road ID and a marking ID.

Color display

The LTL3500 retroreflectometer comes with an easy read-able color touch display – the display is easy visible also in bright sunlight. The touch display is supported by 3 rugged activity buttons.

A few technicalities

Multi-lingual user menu

Measurement of RL and Qd combined in less than 1 sec 

The instrument is electronically stray compensated to ensure correct measurement under all conditions

The instrument comes with long-life and maintenance free illumination

The instrument has 8 GB memory

The instrument is approved to European directives and US requirements related to workers safety and EMC emission


LTL3500 instruments are delivered with a RL calibration reference calibrated in DELTA’s DANAK accredited laboratory in accordance with ISO 17025 and assuring traceability to PTB (Physikalish-Technische Bundesanstalt, Germany) and NIST (National Institute of Standards and Technology, USA).

LTL3500 is factory calibrated for Qd. The instrument is delivered with a Qd calibration marking which can be used for verification and, if necessary, for calibration.



EN 1436, ASTM E 1710, ASTM E 2177, ASTM E 2302, ASTM E 2367 y ASTM E 2832

Maintenance service and calibration

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