EG&G PARC 181
Current Sensitive Preamplifier
10-9A/V MAX DC-200KHZ
The model 181 is a current-to-voltage
preamplifier of low noise and low input impedance designed to
amplify the extremely low low currents encountered in such areas as
photometry and semiconductor research. In photometric applications
the low input noise allows the use of photo detectors with dark
currents as low as 10-14 A/root Hz, while the wide frequency range
permits high modulation frequencies to avoid 1/F noise and
The unit has a high dynamic range, allowing small AC currents to be
amplified without overload in the presence of quiescent (DC)
detector currents up to ten times the current to voltage converter
setting. In semiconductor applications its low input impedance
permits the actual bias voltage applied to the device under test to
be measured without having to correct for the effects of back bias.
Six switch-selectable gain settings from 10-4 A/V to 10-9 A/V are
available and the instrument has a useable frequency range from DC
to 200 kHz. A signal monitor connector is provided on the rear panel
and there is an overload indicator light on the front panel.
A bias control (accessible through an opening in the bottom of the
unit) allows the application of a detector bias voltage at the input
connector in the range 0 V to -5 V, with a nominal source impedance
of 10-5/S, where S is the selected sensitivity. For example, if the
sensitivity is set to 10-7 A/V then the source impedance will be
10-5/10-7, or 100 W. In some cases it may prove convenient to use
this bias control to cancel the effect of DC bias accompanying the
DC Zero Control
A second control, also accessible through an opening in the bottom
of the unit, allows the internal electronics to be DC zeroed.
The unit can be powered from an external low voltage, a lock-in
amplifier via a suitable power cable, or the models PS0055 or PS0056
remote line power supply modules.
Frequency Response (typical): 181fres.gif (13894 bytes)
Input Impedance (typical) : 181inpz.gif (11212 bytes)
Noise Current (typical) : 181inoi.gif (12029 bytes)
Peak Input Current (typical)
A/V Frequency response
DC to Maximum (peak) Input Current
10-4 A/V to 10-9 A/V in six ranges.
Indicates that instantaneous (DC plus peak AC) current has
exceeded amplifier capability
600 W rear-panel BNC connector permits monitoring of the
Provides optional 1:10 attenuation of output voltage
Signal Output Level
6.5 V rms maximum
Signal Output Impedance
1 kW nominal
±15 V or ±24 V at 30 mA
4.5" wide x 6.6" long x 2.7" high (114 mm wide x 168 mm
long x 69 mm high)
2.2lbs (1 kg)
Unit is in excellent physical and electrical
This item is sold with
a 3 Day Satisfaction Guarantee. So bid with confidence.
As our many customers will attest, we will do our very best to resolve
any customer problems. But our official policy is:
This item comes with a 3 day right of return policy.
All returns must be made within 3 days of receipt.
All warranties are void if the calibration / warranty seals are broken.
Equipment must be shipped correctly and returned with all accessories.
Customer is responsible for all shipping charges on returns.
Foreign Buyers please be aware: We offer no warranty or returns on items
shipped outside the USA
Shipping & Bidding:
Buyer will pay $25.00 packing and
shipping in the continental United States. Payments accepted are Paypal,
cashiers checks and money orders only. No international buyers
unless Paypal verified. Please feel free to contact us if you
need other arrangements.
We will make every effort
to ship within 24 hours of receipt of payment. We ship with FedEx &
UPS only. We will be glad to ship with other carriers using the purchasers
shipping account. Please contact us to make any special shipping arrangements.
For shipping rate research, our shipping address is Boulder, CO USA
---- Zip Code is 80305.
Many of our auctions have a set
packaging and shipping fee. This set fee makes the transaction
easier and allows the purchaser to send payment at once without having
to wait for a shipping total. This is our best guess on an unpackaged
item. Please consider the total with shipping when you are bidding.
Foreign buyers: Unless special provisions have been made, you are responsible
for making your own shipping arrangements and all costs related to customs,
duties & special packaging requirements. Please do not ask us to quote
you international shipping rates. Use the address information above
to research you own shipping rates. You can email sales@ascentconcepts
(no spam) .com to get the packaging fee, package weight and size for
your research. Items sold outside the USA are sold as is.
Bidders - with no feedback
or less then 80% positive feedback must contact us through the eBay
email system before placing a bid. We will reply through the same system,
documenting that you have been approved to bid. If you do not follow
these procedures, your bid will be cancelled.
All other bidders, bid with confidence.
Ascent Concepts and Technologies
is a Research & Development Lab. As a service to the companies and institutions
we work with, we broker their excess equipment & act as application
specialists on their new equipment needs. We are now offering quality
used equipment to the public with the same level of professionalism
Please feel free to email
at thomasknox@ascentconcepts (no spam) .com or call Thomas @ 1-303-554-0307
with any Technical questions. Please feel free to email at waltwhite@ascentconcepts
(no spam) .com or call Walt @ 1-720-276-8288 with any Shipping or Logistical
questions. We make every effort to evaluate and guarantee our equipment.
Although we do not provide NIST traceable calibration, we do have extensive
in house calibration equipment and make every effort to test and verify
performance on equipment we sell. However we do not warranty any items
shipped outside the USA.