Delta LTL2000S User Manual

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LTL2000S / SQ RETROREFLECTOMETER

Manual

DELTA Venlighedsvej 4DK-2970Hørsholm Denmark Tel. (+45) 72 19 40 00 Fax (+45) 72 19 40 01 www.delta.dk

DISCLAIMER

The information contained in this document is subject to change without notice.

DELTA LIGHT & OPTICS MAKES NO

WARRANTY OF ANY KIND WITH RE-

GARD TO THIS MATERIAL, INCLUD-

ING, BUT NOT LIMITED TO, THE IM-

PLIED WARRANTIES OF MERCHAN-

TABILITY AND FITNESS FOR A PAR-

TICULAR 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.

Rev. 080104

SW ver: 1.6

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DELTA

LTL2000S(Q) Retroreflectometer

 

INDEX

 

SECTION 1................................................................................................................................

 

1

INTRODUCTION.............................................................................................................................

 

1

Introduction ...................................................................................................................................................

 

1

LTL2000S(Q) features ..................................................................................................................................

 

2

Getting started ...............................................................................................................................................

 

3

Buttons...........................................................................................................................................................

 

3

Measuring......................................................................................................................................................

 

3

Warning and Errors .......................................................................................................................................

 

3

Calibration - LTL2000S ................................................................................................................................

 

6

Calibration - LTL2000SQ .............................................................................................................................

 

8

SECTION 2..............................................................................................................................

 

11

GENERAL INFORMATION ........................................................................................................

 

11

Rl Measurement...........................................................................................................................................

 

11

Qd Measurement .........................................................................................................................................

 

15

Instrument function .....................................................................................................................................

 

17

Factory calibration.......................................................................................................................................

 

17

Notes on error sources .................................................................................................................................

 

17

SECTION 3..............................................................................................................................

 

19

KEYBOARD, DISPLAY AND FUNCTIONS..............................................................................

19

Keyboard Layout.........................................................................................................................................

 

19

Keyboard functions .....................................................................................................................................

 

19

Clear log data...............................................................................................................................................

 

20

Measurement id ...........................................................................................................................................

 

20

Mean Calculation.........................................................................................................................................

 

21

Menu system................................................................................................................................................

 

21

SECTION 4..............................................................................................................................

 

25

MAINTENANCE............................................................................................................................

 

25

General care.................................................................................................................................................

 

25

Protection window.......................................................................................................................................

 

25

Battery .........................................................................................................................................................

 

25

Fuses............................................................................................................................................................

 

26

Lamp............................................................................................................................................................

 

26

Calibration unit............................................................................................................................................

 

26

Light trap .....................................................................................................................................................

 

27

Printer ..........................................................................................................................................................

 

28

APPENDIX A..........................................................................................................................

 

29

COMMUNICATION FACILITIES..............................................................................................

29

RS-232Cspecification.................................................................................................................................

 

29

Data protocol ...............................................................................................................................................

 

31

Command format.........................................................................................................................................

 

32

Command set...............................................................................................................................................

 

33

APPENDIX B..........................................................................................................................

 

36

Status code interpretation ..............................................................................................................

 

36

APPENDIX C..........................................................................................................................

 

37

Print outs..........................................................................................................................................

 

37

Result Printout.............................................................................................................................................

 

37

Rl Calibration Printout ................................................................................................................................

 

37

Qd Calibration Printout ...............................................................................................................................

 

37

Log Printout.................................................................................................................................................

 

38

Status Printout .............................................................................................................................................

 

39

 

 

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DELTA

LTL2000S(Q) Retroreflectometer

 

APPENDIX C..........................................................................................................................

40

SPECIFICATION...........................................................................................................................

40

General Characteristics Rl ...........................................................................................................................

40

General Characteristics Qd..........................................................................................................................

40

Electrical Characteristics .............................................................................................................................

41

Environmental Characteristics.....................................................................................................................

41

Mechanical Characteristics..........................................................................................................................

41

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DELTA

LTL2000S(Q) Retroreflectometer

SECTION 1

INTRODUCTION

Introduction

This manual covers both LTL2000S and LTL2000SQ. Some functions will only be available on LTL2000SQ and will be printed in blue colour.

The LTL2000S is a portable field instrument, intended for measuring the reflection properties of road markings “Rl” as seen in the vehicle headlight illumination.

To measure the Rl properties (coefficient of retro reflected luminance) the road is illuminated at an angle of 1.24 deg. and the reflected light is measured at an angle of 2.29 deg.

The LTL2000SQ is intended for measuring both “Rl” and the lightness of road surfaces and road markings “Qd” as seen under daylight conditions or with stationary lighting.

To measure the Qd properties (the luminance coefficient under diffuse illumination) the road is illuminated with a diffuse source and the reflected light is again measured at an angle of 2.29 deg.

An observation angle of 2.29 deg corresponds to an observational distance of 30 metre, thus relevant for a motorist viewing situation under normal driving conditions.

Rl and Qd is important factors in the ON-SITE quality control of road markings.

LTL2000SQ

LTL2000S

The operation of the instrument is very simple and requires a minimum of instruction. An error message or warning is given in case of unreliable or erroneous measurement.

The LTL2000S(Q) measures the Rl and Qd values according to international agreements. Results are presented in plain English on a LCD display. The built-inprinter andnon-volatilememory provides on site registration of measurements with corresponding date and time.

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LTL2000S(Q) Retroreflectometer

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Serial communication on RS232 port gives extended command, calibration, diagnostics and data dump facilities.

The LTL2000S(Q) is powered by a rechargeable lead acid battery, giving several hours of measurement capacity. A mains powered battery charger is supplied as standard.

LTL2000S(Q) features

Portable self-containedinstrument

Measurement in full daylight

Automatic stray light compensation and error diagnostics

Dry and wet surfaces

Plane, textured & profiled markings

Measurement geometry and illumination corresponding to realistic viewing condition in traffic

Direct digital read out

Automatic mean calculation

Built-inprinter

Real time clock

Automatic data storage in internal non-volatilememory

RS232 serial communication for operation, data dump, extended control and diagnostics

Automatic programmable power off function

Easy calibration procedure

Calibration unit

Carrying case

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LTL2000S(Q) Retroreflectometer

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Getting started

Buttons

Measure

 

Menu

Enter

 

Home

 

OFF

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Calibrate

Print

Sc roll down

Scroll up

ON

Measuring

Turn the instrument on by pressing and holding the button until the LCD shows:

Retrometer

 

Retrometer

LTL2000SQ v1.6

 

2004-01-0810:55

 

 

 

Calibrate the instrument if necessary, see Calibration page 6.

Place the instrument on the road marking. Press the key.

The measurement will start instantly. Duration approx. 3 sec. depending on measurement mode (approx. 5. sec when measuring both Rl and Qd).

When finished the measured Rl (and Qd) values, the date/time or measurement id and status info is displayed. The information’s are automatically transferred to the internal data log for later readout to the serial communication port or printout.

The instrument can automatically calculate and display the mean (average) value of 2 or more measurements, if the Mean Calc function is ON. SeeMenu system.

Warning and Errors

Warning and errors are indicated in the lower right positions in the second line of the display:

*

=

Everything

O.K.

W

=

Warning

Measurement O.K. but warning condition detected.

L

=

Warning

Measurement O.K. but high stray light detected.

E

=

Error

Measurement unreliable.

If the error indicator is different from * then presstoprint–outthe status from the last measurement or pressone or more times to selectStatus Display and then useto

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LTL2000S(Q) Retroreflectometer

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scroll through the status list to see the possible cause of the problem. For further description on the error messages see Status Display page 19. Alternatively or select the menu Print Status to print a complete instrument status.

Note:

When battery voltage becomes low a warning (W) is shown in the lower right corner of display. It is still possible to take measurements but when the voltage drops too low, readings can be erroneous.

If in doubt whether the readings are correct make a control measurement on the calibration unit.

Wet night measurement considerations:

Making wet night measurements on warm road surfaces requires special considerations.

Due to the large thermal mass of the road, the road temperature is not influenced very much by the water.

Pouring water on the hot road surface will generate steam. When placing the instrument on the wet road steam will condense in the instrument also on the front window.

Condense on the optical surfaces will result in measure error!

Tests has shown that steam especially condensate on the outside surface of the front window. When removing the instrument from the road, the dew will evaporate quickly and the instrument will again take correct readings.

It is recommended to make the "wet measurements" at the lowest possible road temperature!

Print Result:

Press to print the result from last calibration or measurement to the printer.

Menu:

Press this key to enter the menu section. Press again to scroll through the menu structure.

From the Menu it is possible to control most of the instrument settings such as mean calculation, data log functions, real time setup and automatic turn off timer, see Menu system page 21.

The measuring mode (Qd, Rl or both) is set using this key.

The sequence of the menu functions changes depending on what mode the instrument is in at the moment. Example: when taking measurements with the mean calculation on the first function shown will be the Clear Mean function.

Home:

Press this key to terminate a menu or calibration and display the latest measurement result, if

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LTL2000S(Q) Retroreflectometer

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the Mean calculation function is enabled and there is more than 1 measurement in the calculation then the number of measurements is shown first.

Scroll Keys:

In normal mode the key activates the Clear Top Log function, in menu mode it is used to scroll through the menu functions and to increment shown values.

In normal mode the key activates the Edit Sequence Id function, in menu mode it is used to scroll through menu functions and to decrement shown values.

For more information about the keyboard buttons please see page 19.

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LTL2000S(Q) Retroreflectometer

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Calibration - LTL2000S

A calibration should always be carried out before starting a new series of measurements.

Calibration is done by placing the calibration unit underneath the instrument between the rails. The easiest way to place the unit is to tilt the instrument backwards.

Figure 1. How to tilt the instrument.

The calibration units are fitted with guidance pins on the outside. The pins mounted in the middle of the longitudinal direction of the unit shall fit in the notch in the rails.

The instrument automatically compensates for zero signal, leakage and other possible error sources, and calculates the calibration factor. This process is fully automatic and if the calibration routine is followed precisely the retroreflectometer will now measure “true” Rl.

Rl Calibration

Rl calibration step 1 to 8 actually consists of two calibrations: a “zero calibration” and a “normal calibration”. The zero calibration is done on the calibrator light trap and the normal calibration on the ceramics. It is important to turn the Rl calibration unit the right way during the calibration sequence. See figure 2 (page 9).

Press the key to enter calibration mode and follow the instructions in the display.

Note:

Step 1 + 4: See figure 2 on how to place the calibration unit. Step 2: The message will be shown for a couple of seconds. Step 3: The message will be shown briefly.

Step 5: The message will be shown for a couple of seconds.

Step 6: Edit the Rl Normal value according to the value printed on the calibration unit. Step 7: Accept the shown normal value.

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LTL2000S(Q) Retroreflectometer

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