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Illuminance Meter T-10 for standard illuminance
measurements and T-10M for small-surface illuminance measurements
Used for measurements of a wide range of illuminance.(0.01 to 299,900
lx, 0.001 to 29,990 fcd) |
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Introduction
Compact, light-weight and easy to use multifunctional illuminance
Meter
The latest generation of Konica Minolta lux meters, the T-10, replaces
the globally successful models of the T-1 series. The small,
easy-to-use handheld meters are capable of measuring intermittent
light sources, can be connected to each other to form multi-point
units and are easily controlled with a PC. They have an extremely
large measuring range of 0.01 to 299,000 lx with automatic range
switching and a large, backlit LCD. All this with Konica Minolta's
renowned high level of precision in a small, compact design.
Areas of application
Konica Minolta lux meters are used whenever brightness and the
quantity of ambient light must be measured. Even the measurement of
average values and illumination is possible. Examples of their use
include the measurement of workplace and street illumination, the
production of lamps as well as architectural, forestry, and
agricultural applications. Deployment in hard-to-reach spaces and
under water are possible, just as the metering of very large surfaces
and projectors (ANSI lumens) by serial connection of several receptor
heads. Metered values can also be visualized graphically and even
fully automated by using the PC software.
Background knowledge
As the names implies, lux meters measure lux (lx). That is the unit of
illumination strength E, the light striking a certain location or the
lumens (F) illuminating a certain surface (A):
E=Φ/A
In nature, luminance ranges from about 0.01 lx on a dark night of a
new moon to about 100,000 lx on a hot summer day. Workplace
illumination is normally around 1000 lx, many standards specify
minimum values for the workplace. In some countries, the unit foot
candles (fcd) is also used to denote illuminance. Of course, the T-10
will also display these values when desired. 1 fcd = 1 lm/ft2 = 10.764
lx
The T-10 series of lux meters can also monitor the integrated
illuminance for up to 9999 hours and then determine the exposure H in
lux hours (lxh). That is the measurement for the amount of light that
falls onto a certain surface within a certain time (t), for example
how much light a plant receives throughout a day:
H = E · t
With the ability to connect up to 30 receptor heads in series, the
T-10 series can be built into a system for the measurement of ANSI
lumens of projectors. The unit lumen (lm) designates the light energy
(F) emitted by the projector. It is measured indirectly over light
striking a certain surface using 9 receptor heads.
Basic model T-10
The general purpose unit for most applications. It is based on the
same base unit common to all models of the T-10 series with
operating panel, analysis unit and display and a removable
standard receptor head. This modular concept allows the
combination of various receptor heads and the expansion of the
unit for adaptation to your measurement tasks.
The most important features at a glance
All models of the T-10 series allow
a comprehensive range of measurement possibilities for analysis that
leave nothing to be desired. The most important operational functions
are accessed using three large buttons. An additional operating panel
for less commonly used features is found under a sliding cover. This
way, you are not distracted by additional operating elements during
everyday work. A large, backlit liquid crystal display shows the
measurement values; the illumination is automatically switched on as
soon as it gets too dark. The T-10 models offer the following
possibilities for analysis:
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Absolute measurement of illuminance in
lux and foot candles.
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Comparison of illuminance values as a difference or percentage
value. The target level can be entered by measurement or
manual entry with the keypad.
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Integrated illuminance (exposure) with a display of the
integration time and the illuminance mean value.
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Other evaluation options with the software T-A30
Other features facilitate daily use of the T-10 even more:
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Automatic, rapid zero calibration (without cap!) after switching on.
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Measurement of continuous and intermittent light sources.
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Very large measurement range of 0.01 to 299,900 lx with automatic
range switching. Range switching can also be done manually.
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Entry of colour correction factors for adaptation to certain light
sources.
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Serial connection of up to 30 receptor heads for multi-point
metering.
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Digital (RS-232C) and analogue output ports for external use of the
measurement values.
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Extensive accessories.
Serial connection
One of the special characteristics of the T-10
series is the ability to connect multiple receptor heads through a
serial port. This allows measurements to be taken at several
points simultaneously without having to move the instrument. That
way, large areas such as movie screens, can be measured easily.
With the help of the T-A30 Software you can measure the ANSI
lumens of projectors for example.
Up to 30 receptor heads can be connected at once and the
measurement values can be called up with the base unit. The
individual receptor heads are connected with a common LAN cable
(10BASE-T) that can be up to 100 metres long. The various receptor
heads are separated from each other and from the evaluation unit.
Multi-point measuring is made very easy with the T-A30 software. The
software also graphically displays the system and allows the
simultaneous display of all measurement values.
Accuracy
Spectral luminous efficiency V(λ) defines the human eye and
instruments should match this spectral response. The chart shows
the T-10's remarkable alignment to this standard curve (f1 (CIE)
within 6%). With discontinuous emitters, even higher accuracy can
be achieved with the colour correction factor. The standard Konica
Minolta calibration is performed to standard illuminant A. The
diffuser in front of the high-grade silicon photo diode is used
for the accurate spatial evaluation of the light being measured.
The ideal condition is cosine-shaped valuation over the wave
angle; the deviation from this is a measure of accuracy. Also in
such case the T-10 shows its strength, see for details of the T-10
cosine error the table and graph hereunder.
10° ± 1%
20° ± 1.5%
30° ± 2%
40° ± 3%
50° ± 4%
60° ± 5%
70° ± 8%
80° ± 20%
Small sensor model T-10M
The ideal instrument if space is tight. With a receptor head of only
16mm diameter (14 mm diameter measurement area) and a 1 metre long
lead, you can measure even hard-to-reach and small spots. The receptor
head of the T-10M can be combined into multi-measurement systems with
the normal receptor head of the T-10. All other features are identical
to the basic model T-10.
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