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How to choose the right types of retroreflectometer?

Views:3     Author:Site Editor     Publish Time: 2020-01-10      Origin:Site

Retroreflectometers are favored by many drivers because they play an important role in road safety, but how should we choose a retroreflectometer that suits us? How should we use a retroreflectometer to be convenient and safe?


Why is a retroreflectometer necessary?

How to choose the type of retroreflectometer?

How to use the retroreflectometer correctly?

Why is a retroreflectometer necessary?

As we all know, the visibility of road signs is very important for traffic flow and road safety. The reflection characteristics provide a measure of the visibility of the road sign using a retroreflector. Road sign management programs that ensure minimum value visibility can help reduce accidents, save money, and provide valuable information assets. Similarly, service performance and economy can be improved if maintenance decisions are based on monitoring rather than on fixed replacement intervals.


Retroreflectometers – use them to improve driving safety. If the road markings or road markings provide the minimum retroreflective level specified in the standard, the use of retroreflectors is the only way to objectively assess – thus providing the best guidance for safe driving in all situations. Retroreflectors can measure retroreflection in seconds and provide undisputed results and demonstrate whether road markings or road markings meet or fail to meet standard guidelines.


Retroreflectometers – help you spend your maintenance budget more efficiently. Financial resources are limited for most of us. There is a road maintenance budget to spend, how do you spend the most effectively? For road markings and road signs, first use available resources to avoid underperforming signs and road signs - and maintain a high level of road safety. The retroreflective meter accurately measures the position of markers and markers during the show and allows you to invest resources here. 

How to choose the type of retroreflectometer?

The type of spectrometer required to measure the visibility of road signs depends on the visibility parameters and the type of road markings that need to be measured. For interfaces to road sign management and GIS systems, reporting and data communication are becoming important functions, and the basic parameters used to characterize the visibility of road signs are nighttime reflections, visibility and reflection under daylight or road illumination.


The anti-reflectivity is characterized by the anti-reflection luminance coefficient, RL. In order to express the visibility during the day, the brightness factor of the diffuse illumination is used. These two parameters are defined in both ASTM E1710 and EN1436. Both standards are based on a simulation of the measurement of the terrain, ie the driver is observing the markings at 30 meters in front of the vehicle. Retroreflectometers for road marking measurements must meet the formal requirements of the standard and are related to 30 m geometry, spectral correction and linearity, and have sufficient profile height to measure the type of profile being measured. In addition, due to the actual field performance, the instrument should have sufficient capacity, adequate calibration standards, and additional functionality to ensure proper measurements under different field conditions*


Night visibility and reflectance RL are expressed in mcd/m2lx and are measured substantially under dry conditions. In addition, the creek can be measured in wet conditions or when it is raining. For the measurement of rills in wet conditions, EN and ASTM specify that the test conditions should be created using clean water in a bucket 0.3 m above the ground. The RL under humidity conditions should be measured after 60 seconds. A wet timer is integrated in the software of some instruments, and an audible signal is emitted after this time. On wet path markings, the RL value is usually small. The surface reflection is stronger. The retroreflective meter should be constructed such that surface reflections do not cause an offset. A possible offset can be tested with a black acrylic plate with a RL of zero. The measured value on this board should not exceed 2m cd/m2.lx.


Testing RL under rainfall conditions requires a fog-free artificial rainfall condition with an average strength of 20 mm/hr. The amount of rainfall was measured after 5 minutes of continuous rainfall or after the measurement was stabilized. The retroreflectometer used to test continuous rainfall must use an open beam configuration and set up a measurement field in front of the instrument.


Based on the 30-meter geometry, daytime visibility and street lighting conditions are characterized by Qd, which is also measured in mcd/m2lx. Qd is only used to dry the surface. Instruments capable of measuring Qd must have a standard specified diffuse illumination system. As can be seen from the above, it is impossible to simultaneously measure RL and Qd under rainfall conditions. Diffuse lighting above the road markings hinders the construction of the girders.


Night color measurement. To measure the nighttime color of the pavement markings, optional features include measuring chromaticity coordinates. In many countries, this is important when ensuring that the yellow pavement marking is yellow rather than white. Observed under realistic driving conditions at night. To measure color, a reflectometer with three filters is used to represent the color sensitivity of the human eye.


The type of material used for road markings, such as paint or thermoplastics, does not affect the measurement of the retroreflector. An important parameter of the instrument is its ability to measure structured road markings or non-planar markings that have textures, curvature hump or particles on the surface. When measuring the structural pavement markings, the retroreflector is placed on top of the structure and measurements are taken on the sides and bottom of the structure. In most retroreflectometers, the measurement field contains an illumination field. In these systems, the measured area of the road markings is the illumination field. Both the ASTM and CEN standards stipulate that the minimum size of this should be 50 square centimeters, but since the road markings may be very uneven, for average measurements, larger venues are highly desirable and require less reading.

The result of a structured road marking is the movement of two fields determined by the height of the contour or the gap between the contours. The height of the retroreflector depends on the ratio of the length of the illumination field to the length of the measurement field.

How to use the retroreflectometer correctly?

1. An important feature of the retroreflective meter is its ease of operation and reliable measurement results. It is best to operate with one hand and the measurement is done with one touch. Measurement time is an important parameter, and the shorter the measurement time, the better. A measurement time shorter than one second is preferable.

2. The display should be easy to read during the day. In addition, the retroreflector should also have features that identify the object being tested. For improved processing, the retroreflective meter can be fitted with wheels and an adjustable handle.

3. Calibration standards and traceability, a very important aspect of all metrology is the traceability of measurements.

4. The built-in printer can be used to print measurement results on the fly. When delivering a retroreflector, you should include software that can download the results to generate a report. Geotagging with GPS map software allows you to link data to geographic maps and GIS systems. The USB, Bluetooth and Ethernet interoperability interfaces make it easy to connect to any PC device, pda and smartphone.


It is certainly wise to choose a retroreflective meter according to your situation, but first make sure that the retroreflectometer is supplied by a qualified vendor. If you are looking for a good quality and reasonable price of retroreflectometer, NANJING T-BOTA SCIETECH INSTRUMENTS&EQUIPMENT CO.,LTD can provide you with the best products.

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