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The following is a list of commonly asked questions regarding
this product. If you have any additional questions,
please feel free to contact us at 800-426-1306 for further
information. |
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| Can
I get a replacement Instruction Manual for this instrument? |
| Additional
Operator's Manuals are available for download by clicking
on the 'Downloads' section from the menu bar at the
top of this web page.
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| Is
it possible to have a Model 1800 amplifier customized
for my preferred gain and filter settings? |
| Yes,
in most circumstances, we can easily customize at our
factory any of our amplifiers' filter and/or gain settings.
Please contact technical support (800-426-1306, or tech@a-msystems.com
for more information.
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| Do
you sell extension cables for your headstages? |
| We
do not sell extensions, however we do sell new headstages
with longer cables (for a small customization charge).
The maximum length is usually 12 feet. Typically, the
main amplifier needs to be returned to us for calibration
with the new longer headstage cables.
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| What
are the major differences between the Model 1700 Differential
Amplifier and the Model 1800 Microelectrode Amplifier? |
| The
1700 has 4 channels and the 1800 has two. The
1800 comes with preamplifiers (probes, headstages) while
the 1700 does not. Thus, while the 1700 and 1800
will work equally well in recording if you have electrodes
that are 1M-ohm or less, recording with high impedance
electrodes will require the headstage probe provided
with the 1800. The Headstage eliminates signal
losses due to long cables and the capacitance they generate.
The 1800 can monitor an external stimulus being delivered
through the recording electrode, while the 1700 can
not. The 1800 has a built-in impedance measuring
circuit, while the 1700 does not.
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| My
Model 1800 is not working, but our university has an
excellent electronics facility. Can we repair the unit
ourselves? |
| It
is recommended that A-M Systems perform the needed repairs
as we are the most familiar with the units. However,
if you are confident in your electronic technician's
skills, you can always purchase the schematics for the
Model 1800 from us (Cat#703000) and attempt them yourself.
Please note that any user-attempted repairs during the
warranty period may invalidate the warranty, and might
invoke additional charges to correct them if A-M Systems
is required to make repairs at a later date.
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| Should
I purchase a Model 1800 or a Model 3000? |
Both
instruments are designed for low noise differential recording of
physiological signals. The Model 1800 is a true AC amplifier. In contrast, the Model 3000 has a DC front end, which also
enables the researcher to record DC offsets that would otherwise be
eliminated by a full AC amplifier, like the Model 1800.
The Model 1800 uses capacity compensation during
impedance measurements only, while the Model 3000
also uses capacity compensation during recording as well as impedance
measurement, while .
The Model 1800
has lower noise than the Model 3000, but both instruments have acceptable
noise levels for high quality recordings.
The Model 3000
can fit within a Faraday cage, as its power input is DC from the remote
power supply.
The Model 1800
has two channels, and two headstages are included. In contrast, the
Model 3000 has only a single channel, and headstages are options available
for an additional charge.
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| What
is the impedance mode? |
| When
the Model 1800 is in impedance mode, a 100nA 1kHz sine
wave is injected into the electrode. With the
capacity compensation control fully counter-clockwise,
the resulting amplitude on the output is proportional
to the impedance (Z=V output / I injected). For
an electrode with 1M impedance at 1kHz, you would get
100mV on the output. The capacity compensation
knob will charge up the capacitance of the electrode
to eliminate it from the measurement leaving only the
resistance of the electrode. So as you turn the
capacity compensation clockwise the capacitance of the
electrode will be eliminated and the amplitude of the
sine wave will increase. When the sine wave starts
to get noisy and approach high frequency oscillations,
you will have compensated for almost all of the capacitance
of the electrode.
If
you would like more information on electrodes, we suggest
a book titled: "Electrodes and the measurement
of bioelectric events." by L.A. Geddes.
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| Can
I use this instrument outside of the United States? |
| All
of A-M Systems instruments can be modified to work outside
of the United States. Typically, this modification is
made at the factory (at no additional cost) prior to
shipping to our customers. Just inform the customer
service department where the instrument will be used,
so our technicians can prepare the proper power supply
modifications.
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| What
are the proper operating and storage conditions for
my Model 1800? |
| The
Model 1800 is designed to be used under laboratory conditions.
Operate in a clean, dry environment only. Do not operate
in a damp environment. Temperatures for storage and
operation should be between 5 ºC and 40 ºC. Storage
should be indoors in a cool dry place.
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