2.1.5 Factor Selector
In the center of the panel is a bracketed area labeled
‘
FACTOR SHIFT
’
, which has a button and a one digit
readout. If the
‘
DATA DISPLAY
’
mode is set to factor,
then the user can select any of 10 different user
programmable sensitivity factors (0-9) that could apply to
different detectors or to different combinations of detector,
filter, and diffuser. These factors are obtained from the
calibration certificate for your particular system. If you
want to read out in current (amperes), dial in 1.000e
0
. See
the next section for changing factors
2.1.6 Changing Factors
There are three BLACK buttons on the left side of the
front panel used for changing the sensitivity factors. They
are marked
‘MSD’
,
‘LSD’
, and
‘EXP’
, which stand for Most
Significant Digits, Least Significant Digits, and exponent,
respectively. The
‘MSD’
button increments the left two
digits of the mantissa, from 1.0 to 9. The
‘LSD’
button
increments the right two digits of the mantissa, from 00 to
99. By holding these buttons down (when in
‘
FACT
OR’
mode), the mantissa digits will increment exponentially up
to a higher value, from 1.000 to 9.99. The
‘EXP’
button
performs a similar function, incrementing the exponent digit
from e-19 to e+19. A full explanation on factor entry is
covered in section 3.2.3.
2.1.7 Bias Voltage
The white button (low center) labeled
‘
5 V
BIAS’,
reverse biases semiconducto r detectors with 5 volts, or it
adds an additional 5 Volt reverse voltage to any vacuum
photodiode for a total reverse selection of 14 volts. In other
words, a silicon detector can be operated without any bias
(photovoltaic mode) for low level and D.C. readings, or with
a 5 volt bias, which increases the speed of response for flash
measurements. A vacuum photodiode always needs a bias,
so it is wired in the connector to give a bias choice of either
9 volts (5 V bias light off), or 14 volts (5 V bias light on).
The bias ON is always the right choice for vacuum
photodiodes (see details in section 3.4.1).
2.1.8 Auto Range
The white button on the lower right side of the front
panel, labeled
‘AU
TO
RANGE’
, gives the user the option to
limit the ranging ability of the system, so one can notice
gross changes in readings at a glance due to either the
‘HI’
indication for too bright, or a very small mantissa for a level
too low. The alternate action of this button selects or de-
selects
‘AU
TO
RANGE’
. If you are over-ranged and wish to
re-establish a new level, you must toggle the function into
‘AU
TO
RANGE’
, then turn off the
‘AU
TO RANGE
’
mode
again. See section 3.2.2 for more details on the use of this
control.
8
2.1.9 Percentage Mode
The other white button in the lower right corner of the
panel selects a relative mode by making the display reading
equal 100.0, and referencing all subsequent readings to this
original value. These readings are a percentage of that
original value. This is very useful for making transmission
measurement s or reflectance measurements directly. You
must establish a reference for the 100% value, by removing
the filter between the light source and the detector or by
using a white reflectance standard for the 100% condition.
There are many applications that require relative
measurements, such as attenuation measurements through an
optical system, or comparisons between two light sources.
For example you could turn on one light and set to 100%.
Then turn that light off and turn the unknown light on to
read the relative value compared to the first lamp. Since
percentage mode disables the auto-range, the largest relative
reading possible is 1999% and the smallest is 0.1%.
2.2 REAR PANEL
2.2.1 Battery Replacement
In the very upper left corner is a printed message which
gives a brief description of how to insert or replace the
internal batteries. The back panel is tricky to remove,
especially on new units, because everything fits tightly. You
must remove the three nickel-plated Phillips screws on older
models. Note: The larger screw goes to the right of the
power input connector. On Newer model there are 4 nuts, 2
beside the sensor input and two beside the RS232 connector
and one Philips head screw at the power cord connector.
Once you remove all screws, yo u must pull the back panel
to the rear by pulling on battery access pull knob (see 6 in
above diagram) with a pair of pliers. To avoid marring the
knob, we suggest you put tape on the knob before you grasp
it with the pliers. While pulling, you should direct your
force up and down to work the assembly to the rear. Be
careful when it lets go, so you do not allow it to move too
rapidly. There are two battery wires that could be broken if
care is not used. Also be careful to notice if one of the
circuit boards is pulled back with the rear panel. It should
NOT be pulled back. Free the board from the rear panel and
carefully push the board back into position so it is even with
the one above it. Set the rear panel assembly on a table
close to the unit without stretching the two wires. You will
now have free access to the battery compartment which
holds six (6)
‘C’
(NICAD ONLY) cells.
2.2.2 AC Voltage
The ILT1700 will come with the AC switch set to
115VAC, it is very important that you check the switch prior
to use. The two choices are 115 (90-130) Volts AC, which is
common throughout most of North America, and 230 (180-
240) Volts AC, which is common throughou t most of Europe.
In some parts of the world (Japan, for instance), the common
voltage is 100 VAC, which is accommodated on the 115 VAC
selection. You make a selection by inserting a pointed tool,
such as a screwdriver, into the slot, to slide the switch left or
right (115 or 230 volts respectively).
代理美国International Light辐照计http://www.testeb.com/yiqi/ilt/zhaoduji.html 深圳市格信达科技 电话18823303057 QQ：2104028976
