Full Text Searchable PDF User Manual
Luxmeter
LX 100
Table of contents
1 Introduction...........................................................................................................................................4
2 General information..............................................................................................................................4
2.1 Photometric values.......................................................................................................................4
3 Operating principle...............................................................................................................................6
3.1 Keyboard presentation..................................................................................................................6
4 Setting..................................................................................................................................................7
4.1 Screen control...............................................................................................................................7
4.2 About.............................................................................................................................................7
5 During measurement............................................................................................................................8
5.1 Range............................................................................................................................................8
5.2 Illuminance....................................................................................................................................8
5.3 Averaged illuminance....................................................................................................................8
5.4 Relative illuminance......................................................................................................................9
6 Running informations.........................................................................................................................10
6.1 Over-range..................................................................................................................................10
6.2 Power source..............................................................................................................................10
7 Maintenance.......................................................................................................................................10
7.1 Servicing.....................................................................................................................................10
7.2 Regular checking........................................................................................................................10
7.3 Batteries replacement – adaptors...............................................................................................10
8 Main specifications.............................................................................................................................11
8.1 Range details..............................................................................................................................11
8.2 Specifications..............................................................................................................................11
8.3 Standard reference.....................................................................................................................11
9 Delivery and packaging......................................................................................................................12
1 Introduction
LX100
instrument is a portable instrument totally automatic built for the measurement of illuminance.
It displays result in Lux or foot candles (footcandle) and provides:
Instantaneous measurement
D
isplay illuminance for local measurements
With timed measurement :
Illuminance min/max values display
Illuminance averaged value calculation
In addition
:
It includes a pause function to eliminate any unrepresentative and unwanted illuminance or just to memorize on the screen a local result.
It allows a relative measurement to reference point for the quantification of increase illuminance or decrease illuminance.
Data are saved when the instrument is stopped or in case of battery failure..
Its sensor is composed by a silicium photodiode, which spectral response is the photopic curve according to CIE standard.
LX 100
instrument is mainly an efficient and easy- to-use instrument : with small size, it has a large display with a resolution of 64*128 pixels, and
involving a very high technology.
2 General information
2.1 Photometric values
Photometric values are values which allows to define the action of electromagnetic radiation on visual function of the eye of an observer.
The average standard eye, adopted by theCIE (International Commission on Illumination), is defined by a function on spectral efficiency which is
relative to spectral for daytime vision or photopic.
Luxmeter
Photometer destined to measurement of
illuminance
, it is equipped with a photo-electric detector and very often a silicium photodiode coupled with
a filter for modify its response to be close-in the most possible of the function of reference V(λ) defined in the CIE.
4
Photopic curve of spectral sensitivity of human eye
during diurnal vision
Luminous flux
The luminous flux of a source is the assessment, according to the sensitivity of the eye, of the amount of light
radiated throughout the area by this source. It is expressed in lumens (lm)..
Luminous intensity
The light intensity is the luminous flux emitted per unit of solid angle in a given direction..
It is measured in candelas, equivalent to
1 lm / sr
.
Luminance
The luminance of a source is the ratio between luminous intensity emitted in one direction and the
apparent surface of the luminous source in the considered direction. Luminance is expressed in candelas per
square meter (cd/m2).
Illuminance
Illuminance of a surface is the ratio of the luminous flux received at the area of the surface. Its
unit is the lux, equivalent to 1 lm/m2. It is also expressed in
footcandle
(fc) according the ratio :
1 fc = 10.76 lux.
LX100
instrument
has been built to measure illuminance , it allows a measurement in lux or footcandle for illuminance levels below 10 lux, with 0,1
lux calculation accuracy and with 1% accuracy beyond until 150000 lux.
Use
:
For each application, it's advisable to control means of measure to obtain valid and consistent results. Means of use of the instrument has at least so
much importance on the result than the quality of the instrument.
It is imperative to take account of the most important parameters including:
1. Position correctly the
LX100
cell, according to adequate and representative plan of the current study. (eg: workstation)
2. Avoid illumination unrepresentative of the study area
3. Deviate significantly from the cell to avoid mitigation area of illumination.
Functions « pause » and « relative level » integrated into
LX100
instrument will allow to avoid these different problems.
5
3 Operating principle
3.1 Keyboard presentation
When being switched on, “measurement screen” is displayed . From this screen, the operator has access to three others screens by pressing
on keyboard; return to measurement screen is obtained by activating
.
6
Function keys
Directly associated with texts to displayed shown above on display
,
they measurement
setting.
Key “
leaves current screen
”.
Screen
key
F
rom measurement screens, gives access to other screens
On/Off
key
1
2
3
5
4
6
1. Screens representing the 3 different modes of measurement
Instantaneous
Average
Relative
2. Configuration screens
Brightness Informations
Instrument offers 2 groups of screens
4 Setting
Accessible from principal measurement screen by successive pushes on key , those different screens allow instrument setting. They also
inform users.
4.1 Screen control
To optimize display reading, the operator can :
1. Adjust brightness by pressing on and function keys.
2. Backlight LCD display for a better reading in a dark place.
“No”
means backlight is switch off and “
Yes”
it is switch on.
In this last case, battery life is reduced by about 15%.
4.2 About...
Information on origin of manufacture, standard references of the instrument and dates of
last and next audits..
By Pressing
and
keys
you can choose language : French or
English.
A press on or keys allows the choice measurement unit :
Lux
or
Footcandle
.
Note
: unit, lux or fc is independent of the used language.
7
+
-
Brightness
About – English
About - French
5 During measurement
5.1 Range
The digital processing of the instrument avoids for users choice of a range of
measurement,
LX100
instrument displays results of measurement in lux or fc on all of its
dynamics. To cover the whole field, the screen automatically presents the different formats
and units.
5.2 Illuminance
From the start, the instrument measures and displays twice a second the instantaneous value of illuminance expressed in
Lux or fc. This value gives information to users about illuminance local conditions.
Min. and max. values completes the screen.
User can at any time by pressing the keys :
: Reset minimum and maximum values
: Enable pause
: Continue measurement
5.3 Averaged illuminance
Measurement principle :
From the sampled data, the instrument calculates and displays on the measurement duration :
Instantaneous value at rate of two displays per second
Average value
Max and min values
8
Lux mode
Footcandle mode
Illuminance
1 x
Launching of the stopwatch, it indicates seconds -minutes-hours-days (max : 03D00H00M00). First values,
(
average
,
max
and
min)
. During measurement, no other function is accessible.
From the start screen, user accesses to the Moy measurement of illuminance on a period controled by stopwatch, he proceeds as
follows:
1 x
Access to
Moy
screen.
Measurement is not launched yet.
1 x
In case of poor readability, user can at this moment modify brightness and/or activate backlight.
1 x
Stop of measurement, ''
Reset
'' is displayed.
New measurement
After recording results in his folder, user can launch a new measurement, he proceeds as
follows :
1x
: a sign RESET ? alerts the user of the future reset of memory backup. In
case of change of mind, pressing or inhibits the action.
2x
: Memory is erasing , visualized by the progress bar.
Memory is erased, the operator can launch a new measurement.
Stop of the instrument
In case of stop of the instrument, intentionally or accidentally (low battery), results are saved automatically and systematically presented to the user
before the launch of a new measure.
5.4 Relative illuminance
Principle :
To find the contribution on measurement result by the contribution or removal of a light source, LX100 instrument allows a relative measurement
from an existing situation.
For example: knowing the impact of deleting or adding a lighting (neon tubes) in a room.
Proceed as follows :
From the start screen, user accesses to the measurement of the illumination
1 x
then
1 x
:
access to the screen. The function is not yet launched.
1x
: Press Zr key – screen shows:
Down :
the instantaneous value of illuminance (598.9 lux here), it will serve as
reference. It remains fixed and stored.
At the top :
the value of fluctuating instantaneous illuminance (1268 lux here)
In the middle :
in the panel marked
R
, it is the difference between instantaneous
value displayed at the top and reference value stored down. This value can be
positive or negative according to fluctuations of illuminance compared to the moment
of memorization of the reference value ( key
)
9
Reset ?
Erased data
Rel
Moy
Inst
Value displayed at the top of the
screen represents instantaneous
illuminance
Moy
Zr
Example 1
Example 2
Reference
illuminance
Fluctuating
instantaneous
illuminance
Relative illuminance
Fluctuating
instantaneous
illuminance
Relative illuminance
Reference
illuminance
6 Running informations
6.1 Over-range
Under conditions of measuring range excess, defined at 150,000 lux, an over-range pictogram appears. It comes fleetingly for an
illuminance exceeding 150 000 lux . Displayed value will be 150.1 klux.
6.2 Power source
When the instrument is equipped with alkaline batteries, it can operate for
72 hours minimum
. A symbol informs the user about
electric power remaining. If battery is low, less than 1 bar on the pictogram, the instrument stops measuring, saves current
measurement and switches off.
7 Maintenance
7.1 Servicing
The LX 100 conception allows a reduced maintenance, which consists in changing batteries and cleaning the instrument and sensor with a slightly
dampened cloth. A particular attention must be paid to the white disc covering the silicon photodiode which surface must not have dirts or scratches
7.2 Regular checking
Like most measuring instruments, it is strongly recommended to regularly control and calibrate
LX100
instrument. The sensor sensitivity decreases
depending on measurement durations and illuminance intensity. Return to the manufacturer each year will provide necessary metrological
traceability.
7.3 Batteries replacement – adaptors
Batteries :
To replace batteries, open the back hatch and insert the 3 new batteries of type 1.5 V / AAA-LR3 inside.
Warning
: respect meaning of batteries. If storage is very long, remove batteries.
Adaptor
:
If necessary for a long period of measurement, use a USB adaptor .
Note:
when using with an external power, it is recommended to remove batteries from LX100. An internal protection, however, allows to secure all if
you forget it.
8 Main specifications
8.1 Range details
lx value
Display
Unit
lux resolution
Minimum accuracy
of calculation
0 to 10
0.1 to 10.0
lx
0.1
0.1 lux
10 to 99
10.0 to 99.9
lx
0.1
1%
100 to 999
100.0 to 999.9
lx
0.1
1%
1000 to 999
1000 to 9999
lx
1
1%
10000 to 99999
10.00 to 99.99
klx
10
1%
100000 to 150000
100.0 to 150.0
klx
100
1%
fc value
Display
Unit
fc resolution
Minimum accuracy
of calculation
0 to 1
0.00 to 1.00
fc
0.01
0.01 fc
1 to 99
1.00 to 99.99
fc
0.01
1%
100 to 999
100.0 to 999.9
fc
0.1
1%
1000 to 9999
1000 to 9999
fc
1
1%
10000 to 13940
10.00 to 13.94
kfc
10
1%
10
8.2 Specifications
Measuring range
from 0,1 to 150 000 Lux
from 0.01 to 13940 fc
Spectral response
as per standard photopic curve
V(λ) NF C 42 -710 class C.
Error limit V(λ) (f1)
< 10%
True cosine evaluation (f2)
< 6%
Linearity (f3)
< 3%
Measurement capability
3 days – 03D00H00M
Display
Backlit LCD graphic 128x64.
Working temperature
from 0°C to +50°C
Storage temperature
from 0°C to +50°C
Housing dimensions (without sensor)
120x58x34 mm
Weight (housing+sensor+battery)
185 gr
Digital electronic
low drift
Mini-USB plug
for USB power supply adaptor
Power supply
3 batteries 1.5V type LR3-AAA
Battery life
72 hours min, continuous operation.
Electromagnetic compatibility
according to 89/336/CEE
Conformity
as per RoHS
8.3 Standard reference
This instrument is based on recommendations and requirements of the NF C 42-710 standard, February 1988, C class
9 Delivery and packaging
•
LX100
housing with silicon photodiode sensor and glass filter correction.
•
Transport case
•
3 batteries LR3-AAA
•
Calibration certificate
•
LX100
user manual
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