Delta LTL-XL User Manual
DELTA · Ven lighedsvej 4 · 2970 Hørsholm · Denmark · Tel. +45 72 19 40 00 · roadsensors@ de lta.dk
LTL-XL RETROREFLECTOMETER
Manual
On site quality control of road markings & road surfaces in accordance with CEN / ASTM
specifications
ii LTL-XL Retroreflectometer DELTA
DISCLAIMER
The information contained in this document is subject to
change without notice.
DELTA LIGHT & OPTICS MAKES NO WARRANTY OF
ANY KIND WITH REGARD TO THIS MATERIAL, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. DELTA LIGHT & OPTICS SHALL NOT BE
LIABLE FOR ERRORS CONTAINED HEREIN OR FOR
INCIDENTAL OR CONSEQUENTIAL DAMAGES IN
CONNECTION WITH THE FURNISHING, PERFORMANCE
OR USE OF THIS MATERIAL.
LTL-XL IS BUILT ON GENERAL PUBLIC LICENSE COMPONENTS. THE SOURCS CODE IS AVAILABLE UPON
REQUEST.
Caution: Changes / modifications not approved by the re-
sponsible party could void the user’s authority to operate the
equipment.
NOTE: This equipment has been tested and found to comply
with the limits for a Class A digital device, pursuant to part
15 of the FCC Rules. These limits are designed to provide
reasonable protection against harmful interference when the
equipment is operated in a commercial environment. This
equipment generates, uses, and can radiate radio frequency
energy and, if not installed and used in accordance with the
instruction manual, may cause harmful interference to radio
communications. Operation of this equipment in a residential
area is likely to cause harmful interference in which case the
user will be required to correct the interference at his / her
own expense.
Update, August, 2016
Version 1.04a English
DELTA LTL-XL Retroreflectometer
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iv LTL-XL Retroreflectometer DELTA
DELTA LTL-XL Retroreflectometer
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TABLE OF CONTENTS
SECTION 1 ................................................................................................................................ 7
OPERATING INFORMATION ...................................................................................................... 7
LTL-XL introduction ................................................................................................................................ 7
LTL-XL retroreflectometer features ......................................................................................................... 8
Options ...................................................................................................................................................... 8
Getting started ........................................................................................................................................... 9
Important guide lines for the correct use of the LTL-XL ....................................................................... 12
SECTION 2 .............................................................................................................................. 13
GENERAL INFORMATION ........................................................................................................ 13
Measurements ......................................................................................................................................... 13
Notes on error sources ............................................................................................................................ 13
High temperature conditions. .................................................................................................................. 14
SECTION 3 .............................................................................................................................. 15
THE USER INTERFACE .............................................................................................................. 15
Display and keyboard layout .................................................................................................................. 15
Measurement display / HOME screen .................................................................................................... 15
Upper icon row ....................................................................................................................................... 15
Lower icon row ....................................................................................................................................... 16
Push buttons ............................................................................................................................................ 16
The menu tree ......................................................................................................................................... 18
Setting up for measurements ................................................................................................................... 19
Selecting a User ID ................................................................................................................................. 19
Selecting a road marking icon................................................................................................................. 21
Setting the date and time ......................................................................................................................... 21
Setting the dimmer and back light (Display) .......................................................................................... 22
Setting the sound level ................................................................ ................................ ............................ 23
Auto Sleep (Power) ................................................................................................................................. 23
Auto Off (Power) .................................................................................................................................... 24
Setting the language ................................................................................................................................ 24
Setting the temperature unit .................................................................................................................... 24
Setting the SMART key function ........................................................................................................... 24
Using GPS (optional) .............................................................................................................................. 24
Setup (basic and advanced) ..................................................................................................................... 26
MEASURE TYPE ........................................................................................................................... 27
RL & Qd .................................................................................................................................................. 27
Wet timer ................................................................................................................................................ 27
Timer Alarm ........................................................................................................................................... 27
SERIES ID ....................................................................................................................................... 28
Working with series ID ........................................................................................................................... 28
Activate ................................................................................................................................................... 28
Selecting a series ID ............................................................................................................................... 28
Enter a new series ID .............................................................................................................................. 29
Removing a series ID .............................................................................................................................. 29
Presetting the road marking icon ............................................................................................................ 29
THE LOG ........................................................................................................................................ 31
Clearing data in the log ........................................................................................................................... 31
Viewing the log ................................ ................................ ................................................................ ....... 32
View series data. ................................ ................................................................ ..................................... 33
OTHER SETTINGS ....................................................................................................................... 34
Average function .................................................................................................................................... 34
Editing names ......................................................................................................................................... 35
Auto print ................................................................................................................................................ 35
vi LTL-XL Retroreflectometer DELTA
Diagnostics ............................................................................................................................................. 35
The help system ...................................................................................................................................... 35
Errors and warnings ................................................................................................................................ 36
RSC software program ............................................................................................................................ 36
SECTION 4 .............................................................................................................................. 37
MAINTENANCE ............................................................................................................................ 37
General care ............................................................................................................................................ 37
Protection window .................................................................................................................................. 37
Battery .................................................................................................................................................... 37
Fuses ....................................................................................................................................................... 39
Lamp ....................................................................................................................................................... 39
Calibration unit ....................................................................................................................................... 40
Calibration .............................................................................................................................................. 41
Printer (optional) ..................................................................................................................................... 43
Mounting the wheel unit (option) ........................................................................................................... 44
APPENDIX A .......................................................................................................................... 45
COMMUNICATION FACILITIES .............................................................................................. 45
RSC software program ............................................................................................................................ 45
APPENDIX B .......................................................................................................................... 46
SPECIFICATION ........................................................................................................................... 46
General characteristics ............................................................................................................................ 46
Environmental characteristics ................................................................................................................. 47
Mechanical characteristics ...................................................................................................................... 47
APPENDIX C .......................................................................................................................... 48
DELIVERY ..................................................................................................................................... 48
Visit our web-site “www.roadsensors.com”
DELTA LTL-XL Retroreflectometer 7
SECTION 1
OPERATING INFORMATION
LTL-XL introduction
The LTL-XL retroreflectometer is a portable field instrument intended for measuring the
retroreflection and reflection properties of road markings. LTL-XL measures the RL value
(coefficient of retroreflected luminance at night) and the Qd value (day light visibility). RL is
a measure of the lightness of the road marking as seen by drivers of motorized vehicles in car
headlight illumination. The road is illuminated at an angle of 1.24The illumination for Qd is
diffuse. The reflected light for both RL and Qd is measured at an angle of 2.29, which corresponds, to an observation distance of 30 meters. This is relevant for a motorist’s viewing situation under normal conditions. Further information on measuring principles and standards can
be found on www.roadsensors.com.
Figure 1. The instrument
The operation of the retroreflectometer is very simple and requires minimal instruction.
The LTL-XL measures the retroreflectivity and calculates RL and Qd according to the international CEN and ASTM standards. Results are presented in plain text on a large graphic display. Error messages or warnings are shown in the display in case of any problems during use.
The memory of the instrument provides registration of measurements with corresponding
date, time and other relevant data. The following data is also registered (if enabled):
RL and Qd are important factors in the ON-SITE quality control of road markings.
8 LTL-XL Retroreflectometer DELTA
• Name of measuring series (road name)
• Profile icon for road marking type
• User name
• GPS data (if installed)
• Temperature & humidity
• Instrument status
The measurement results can be printed by the built-in printer (optional). Communication
with a PC using the RSC (Road Sensor Control) software program (see pg. 36) allows for data
exchange with other PC programs.
A rechargeable NiMH (Nickel-Metal Hydride) standard battery powers the LTL-XL, allowing
approx. 1,100 measurements on a new and fully charged battery. The optional high capacity
battery can provide approx. 2,500 measurements. A mains powered 15V power adaptor for
charging is supplied as customary delivery. Charging time is approx. 1½ hour for the standard
battery and 3½ hour for the high capacity battery. The instrument can also be charged from a
15-18 VDC source. For field charging the 15V power supply could be powered from an “AC
power inverter” connected to the car battery.
LTL-XL retroreflectometer features
• Portable instrument
• Ergonomic operation height
• Fast measurement (completed in less than 1 sec. for RL or Qd and 3 sec. for RL +Qd)
• Measuring on dry and wet surfaces
• Will measure flat, textured & profiled markings up to 5 mm
• Fully documented measurements with automatic data storage, user and series identi-
fication for labeling and grouping measurements
• Audible signals during use (if enabled)
• RSC (Road Sensor Control) PC software for data exchange. Log data can be
exported to applications such as Microsoft Excel or displayed on Google Earth
• Easy one-step calibration procedure
• Traceable and accredited calibrated reflection standard
• User replaceable battery
• Fast charging, approx. 1½ hour for standard and 3½ hour for high capacity battery
• Rechargeable from mains using power
• Average (2-99 readings)
• Multiple languages
Options
• Built-in GPS for precise logging of measuring location
• Wheel unit and extendable handle
• Build-in thermal printer
• High capacity battery
DELTA LTL-XL Retroreflectometer 9
Getting started
Buttons:
HELP ON/OFF
MENU SMART
HOME CALIBRATE
BACK PRINT
UP
LEFT RIGHT
OK (center)
DOWN
Figure 2. Buttons
Height adjustment (optional)
Before using the LTL-XL, notice that the operating panel can be adjusted in height for ergonomic considerations. The height is adjusted by pressing the red knob on the front of the
instrument and at the same time lifting the handle on the operating panel. Release the knob
and continue lifting until the handle locks.
Turn on
Turn on the LTL-XL by pressing and holding the ON/OFF button until the display
turns on. The instrument will be ready for measuring within 10 seconds. The LTL-XL
wakes up from standby within 1 second.
Measuring
Calibrate the instrument if needed. DELTA recommends calibrating the instrument every
time the instrument is switched on and / or starts a new series of measurements or minimum once a day typically in the morning before measurement start. See Calibration, pg. 40
Place the instrument on the road marking. See positioning on the road pg. 12
Press the green OK-button to take a measurement. A single RL or Qd measurement
takes approx. 1 sec. A combined RL and Qd measurement takes 3 sec.
When the measurement is complete, the RL and/or Qd value will be displayed. Data is automatically transferred to the data log. If there is a problem with the measurement a warning icon or an error icon will pop up (see Errors and warnings, pg. 36) and an audible alarm will
sound (if enabled, see Sound settings, pg 27).
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Measurements taken with a low battery warning are marked in the log and a warning icon
appears. If battery voltage gets too low measurements can’t be taken and an error icon ap-
pears.
To print the latest measurement data, press the PRINT button (Requires the printer op-
tion).
User select (user initials)
If a user icon is displayed in the upper icon row on the measuring display, press the UP
button ▲and if necessary ◄ or ► to mark the user icon. Press the OK button to enter the
user select menu. For further information see Selecting a user id, pg. 19.
Series ID select (name)
If a user icon is displayed in the upper icon row on the measuring display press the UP
button ▲to mark the road icon. Press the OK button to enter the Series ID select
menu. Select a name from the list using UP or DOWN and accept with OK or ENTER /
EDIT a new name.
If the icon is not shown or if further information is need, see Series Id, pg. 28
Calibration
The instrument is supplied with a reference calibration unit. The reference calibration unit
is factory calibrated and traceable to PTB (Physicalish-Technische Bundesanstalt, Germany) and NIST (National Institute of Standards and Technology, USA).
Calibration procedure
Before a calibration is carried out make sure that the calibration unit is clean.
To carry out a calibration go through the following steps:
• Before mounting the calibration unit check the RL and Qd values stamped on the cal-
ibration unit.
• Mount the calibration unit underneath the instrument. Make sure that the pins on the
interface plate fit into the holes on the calibration unit. Be very careful when you
place the instrument on the calibration plate not to damage the calibration unit and /
or the light diodes
• Press the CALIBRATION button once. Select RL or Qd calibration to calibrate one
at a time.
• Adjust the calibration value shown in the display so it matches the value stamped on
the calibration unit. See the Calibration section for details.
• Press the OK button to finish the calibration. If an error occurs ensure that the
• preceding steps have been taken and try again.
• Repeat the calibration process for the other quantity (RL, Qd)
The calibration procedure is now complete. Remove the calibration unit and store it properly.
Press OK to return to the measurement display. For further details see pg. 41
DELTA LTL-XL Retroreflectometer 11
Errors and warnings
An error or warning icon will appear in the upper row of the display if the LTL-XL detects
a problem. Press the UP button ▲ to get a description of the most serious error or warning.
Press the UP button ▲ to get a description of the most serious error or warning. Now press
the OK-button to display a total list of all errors or warnings related to the measurement and
the instrument in general.
Sound setting
Press the MENU button and select SETTINGS / SOUND. Select KEY CLICK or SOUNDS to
set the individual sound levels for key click and system sounds. Use the UP ▲ or DOWN ▼
button to set the level. Accept the setting by pressing the OK button.
Miscellaneous
The HOME screen can be activated at any time by pressing the HOME button .
Reset log: Press the MENU button and select LOG / CLEAR DATA.Now se-
lect from the menu: CLEAR LAST DATA, CLEAR ALL DATA or
CLEAR SERIES DATA.
Date and time: Press the MENU button and select SETTINGS / DATE & TIME / SET
TIME/DATE. Use the UP ▲ and DOWN ▼ buttons to set the differrent time related settings.
Power save: Press the MENU button and select SETTINGS / POWER / AUTO
SLEEP, AUTO OFF. Use ▲and ▼ to edit the values.
Data exchange / communication
The RSC software program, developed by DELTA for use on a PC, allows data to be exchanged between the LTL-XL and a PC. See RSC-program, pg. 36
12 LTL-XL Retroreflectometer DELTA
Important guide lines for the correct use of the LTL-XL
Positioning of the instrument on the road marking
Select an area of the pavement marking that is level when taking readings. The measurement
field is marked with a yellow sticker on one side of the base cover. The measurement field is
approximately 50 mm / 1.97 inch wide and 185 mm / 7.28 inch long. Ensure that the pavement marking to be measured before taking measurements is free of debris. Make sure that
the instrument is stable positioned.
Reason: The LTL-XL has three support pads, each with a small footprint, two smaller in the
front and one larger at the back. An uneven marking or a small piece of gravel trapped below
one of the pads will move the measurement field and affect the reading.
Taking the measurement
Press the green OK button to take a single or double reading as selected. Do not put pressure
on the handle when taking a measurement.
Reason: Pressure on the handle can tilt the instrument slightly and affect the measurement
geometry and thus influence the reading.
Number of measurements.
For accurate readings, do not take just one reading of a road marking. Three readings will
give a more accurate result than one reading. Five readings will give an even more accurate
result than three readings, etc. Take the readings in adjacent areas of the marking. Let the instrument calculate the average of the readings (fixed or moving average options).
Reason: A road marking’s retroreflectivity varies from area to area. It is not unusual to see
variations of 5% - 20% when the instrument is moved even less than 10 mm / ½” in either
direction.
Protective display shield.
For the protection of the display and longevity of the instruments keep the display shield
closed when the instrument is not used. For further information please see section 2.
Remember:
Read:
▪ LTL-XL is an optical precision instrument, handle with care.
▪ Keep the protection window and calibration unit clean and undamaged.
▪ Store in a clean, dust free and dry environment.
Measurement practise for road markings. This leaflet can be located on:
http://www.roadsensors.com
DELTA LTL-XL Retroreflectometer 13
SECTION 2
GENERAL INFORMATION
Measurements
The LTL-XL retroreflectometer measures the RL (coefficient of retroreflected luminance) parameter and Qd (the day light visibility). The RL parameter represents the brightness of road
markings seen by drivers of motor vehicles by headlight illumination. Qd represents the visibility of the road markings under day light conditions.
In the LTL-XL the illumination angle is 1.24 degrees for RL, the illumination for Qd is diffuse. Both observation angles are 2.29 degrees. According to both ASTM and CEN standards
these angle simulates a driver’s viewing distance of 30 meters. The instrument’s illumination
field is approximately 185 mm x 50 mm / 1.97 x 7.28 inch.
Push the button from the HOME screen to take a measurement. Shortly after, the RL and
related information are presented on the colour display. The result is automatically transferred
to the internal memory. The measurement, along with its corresponding time, date, and other
data can be printed using the (optional) built-in printer.
Every measurement contains status information. If an error occurs the information can be interpreted by the warning/error icon in the top line of the display. The information is available
until a new measurement is taken. The status information is stored in the log.
Notes on error sources
Stray light can occasionally enter the instrument but will be insignificant under normal measurement conditions. The LTL-XL compensates for stray light automatically.
Instrument drift and offset errors are compensated by means of data obtained during the calibration procedure. It is very important to keep the dust-protection window and the ceramic on
the calibration unit clean.
The LTL-XL illumination angle is 1.24° relative to the road surface. Because of this small
angle accurate placement on the road is important. Avoid pebbles and abnormal irregularities.
The LTL-XL must be parallel and in contact with the marking surface.
The LTL-XL retroreflectometer is a rugged instrument, but it is an optical instrument and
must be handled as such.
The LTL-XL is factory calibrated. Nevertheless start measurements with a calibration. Study
the display for any warning or error icons. See also Section 4 - Maintenance
Note
Keep the dust-protection window and ceramics on the
calibration unit clean.
Keep the battery fully charged. A well charged battery is
more resistant to aging and damage.
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High temperature conditions.
Display
If the display is exposed to intense direct sunlight during a longer period of time the display
may overheat. It is recommended to close the protective display shield. The shield also protects against damages and scratches. "Daylight readable" displays are vulnerable to high temperatures. High temperature will decrease the display service life.
Battery
The battery is rated to operate between 0C / 32F and 45C / 113F.
Fig 3. LTL-XL, the inside
DELTA LTL-X Mark II Retroreflectometer 15
SECTION 3
THE USER INTERFACE
Figure 4: The HOME screen
Display and keyboard layout
The user interface consists of a rectangular display surrounded by push buttons. The display
has two main modes: the measurement display (HOME screen) and the menu display. The
instrument will start up with the measurement display shown. The display area is divided into
four areas: a large main display in the middle, an icon row at the top, a message or caption
field underneath and an icon row at the bottom.
Measurement display / HOME screen
Here the latest measured RL and/or Qd values are presented with large digits together with
other information. On the graphic in figure 4, all available information’s are shown in the display. If a function is deactivated, it will not be shown. The actual date and time is always
shown.
Upper icon row
The upper row of icons is accessed by pressing the UP button ▲. One of the icons is then
highlighted and can be activated by pressing the OK button. The other icons in the row can be
accessed by using the LEFT ◄ or RIGHT ►buttons. The meanings of the icons are (from left
to right):
• Series ID selection, can be switched off (see pg.28).
• User ID selection, can be switched off (see pg. 19).
• Error/warning alarm. Will be shown in case of an error/warning (see pg. 36).
• GPS indication (see pg. 24).
• Battery status (see pg. 39).
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