
Bulletin 510-EN
Digital Lux Meter
510 series
Excellent Performance and Multi Functions
Simple Function Type : 51011, 51012
Multi Function Type : 51021
51011, 51012 5 102 1

Excellent Performance, Multiple Functions
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
800 850750700600 650550500450400350
Sensitivity
Relative spectral response
Wavelength [nm]
Standard spectr al luminous
efciency
Relative spectral response
(typical response of the 510 series)
Characteristics of oblique incident light
50 60 70 8040302010-10-20-30-40-50-60-70-80 0
30
20
10
0
-10
-20
-30
Error (%)
Deviation from the cosine law
Typical response of
the 510 series
Tolerance compatible
with Class AA
Angle of incidence (degrees)
-
510 Series Digital Lux Meter
Wide range, high accuracy
Simple Function Type
●
51011: 0.0 to 999,000 lx (5range), ±4%rdg±1dgt
51012: 0.0 to 999,000 lx (5range), ±2%rdg±1dgt
●Multi Function Type
51021: 0.00 to 999,000 lx (6range), ± 2%rdg±1dgt
Excellent characteristics <1
>
----Visible region relative spectral response
The relative spectral response of the lux meter should
ideally be the same degree of brightness as V(λ),
which is the unit of brightness to which human beings are
considered sensitive. In the JIS standard, the system of
evaluating the characteristics of the visible region relative
spectral response is adopted in order to bring the relative
spectral response of the lux meter much closer to this
ideal. The following diagram shows the relative spectral
response (typical response) of the 510 series lux meter
which conforms to this system.
Timer hold function
This function is added so that the shadow of the user or reections
from clothes do not affect the measuring intensity of illumination.
Like an selftimer function of a camera, a measured value is held ve
seconds after the switch has been pressed. The 51021 lux meter
can be set arbitrarily from 1 to 999 seconds.
Conventional Lux meter 510 series Lux meter
Color correction factor setting function
The 510 series lux meter measures the intensity of illumination
more accurately because its sensitivity approximates to the
standard spectral luminous efciency which is the same sensitivity
as the human eye. However, since spectral characteristics differ
depending on the light source types, a subtle indication error
occurs. The 51021 lux meter incorporates a function to correct
this error. (Factor xed: 8 types; arbitrary factor setting: 21 types)
Light source luminous intensity
measurement function
The luminous intensity (candela) can be measured easily by setting
the distance from the light source (0.01 to 99.99m).
Average illuminance computation function
(correspondence to 4-point and 5-point methods)
This function automatically calculate 4 or 5 points average of
illumination.
JIS C 7612 [Illuminance Measurements for Lighting Installations]
describes how to calculate the average illuminance using the
4-point and 5-point methods.
The method of evaluating the performance determined by the Commission
*
Internationale de I'Eclairage (International Commission on Illumination) (CIE) has
been adopted in the JIS standard (which the 510 series conforms to) for evaluating
the relative spectral response. This response is classied according to its degree.
Excellent characteristics <2
>
----Oblique incident light
To measure the intensity of illumination from a light source in an
oblique direction accurately, there is a necessity that the angle of
incidence to the perpendicular line from the target of the surface
is in proportion to the cosine law.
51011, 51012
USB function
(Power supply and communication)
●
With the USB interface, it can be used as a power supply
source for continuous measuring with recorder output or/and
USB communication.
The accuracy corresponding to oblique lighting is classied in the JIS standard (which
*
the 510 series conforms to) according to its degree to bring the characteristics of
the oblique lighting on the illuminance meter much closer to the cosine law.
5 102 1

Specications
Model 51011 51012 51021
Standard
Photoelectric element
Display
Measurement cucle
Measuring range
Accuracy(*)
Response time
Fatigue characteristics
Temperature characteristics
Characteristics
of oblique
incident light
Characteristics of visible-spectrum
response
Operating
temperature / humidity
Function
Communication
Output
Dimensions, weight
Power supply
Accessories attached
:At23±2˚C
*
Accuracy: ±% of reading ± effective min. digit
Conforms to class A of JIS C1609-1 2006 "Illumination Meter"
Silicon photodiode
Liquid crystal display (number of 7 digits);maximum effective display:999; (0 or 0's to indicate the number of digits)
Twice per second
0.0 to 99.9/999/9,990/99,900/999,000lx 0.00 to 9.99/99.9/999/9,990/99,900/999,000lx
±4% rdg ±1dgt (under 3000lx)
±6% rdg ±1dgt (over 3000lx)
Automatic range : 5 sec; Manual range: 2 sec
±2% ±1%
±5% ±3%
Angle of :10° ±1.5%
30° ±3%
60° ±10%
80° ±30%
(deviation from cosine law)
Deviation from the standard spectral
luminous efciency: f1' within 9 %
-10 to 40°C 80% RH or less ;no moisture condensation
Response switching, Range Hold, Timer Hold, Deviation
display, Auto power off
USB (Mini-b 5pin)
DC 1V ±5%(xed range); load resistance: 100kΩ or more
Approx. 67(W) x 177(H) x 38(D) mm; Approx. 260g
AA (LR6) x 2 OR USB supply (5VDC ±5%)
Instruction manual; dry cell(built in); soft case; recorder output plug
Conforms to class AA of JIS C1609-1 2006
"Illumination Meter"
±2% rdg ±1dgt (under 3000lx)
±3% rdg ±1dgt (over 3000lx)
Angle of : 10° ±1%
30° ±2%
50° ±6%
60° ±7%
80° ±25%
(deviation from cosine law)
Deviation from the standard spectral
luminous efciency: f1' within 6 %
Response switching, Range Hold, Timer Hold, Deviation
display, Auto power off, Color correction factor setting,
Average illuminance computation,
Ripple measurement, Light source luminous
intensity measurement, Measurement of totalized
intensity of illumination
Spare parts
Name Model Specication
Soft case
Recorder output Plug
RB038A For 51011/12/21
JC017A
Accessories (Sold separately)
Name Model Specication
Extension cable for light detector
Extension cable for light detector
For recorder output
91001 3m
91002
30m