MODEL 121 PRECISION LOWNOISE DC AMPLIFIERSPECIFICATIONS

3-Channel DC Differential Amplifier
Programmable Gain & Output Scaling<20µVrms Input Noise
Includes Auto-Zero Function
DC to 200kHz Bandwidthdimensions
The Model 121 is a state-of-the-art, 3-Channel Precision DC Amplifier
designed to be used with bridge type, single-ended, and differential voltage
output accelerometers, pressure transducers, and load cells. The amplifier
offers an exceptionally low input noise floor of <20µVrms and widebandwidth to 200kHz, ideal for transient measurements.
The Model 121 amplifier is also shunt calibration capable and incorporates
adjustable 4-pole Butterworth filter modules.

FEATURES

AC/DC Front Panel Voltage Display±12.5Vdc Dual Excitation Voltage
0-25Vdc Single-Ended Excitation Voltage±20mV Auto-Zero Function
4-pole Butterworth LP Filters
Shunt Calibration Function

APPLICATIONSInstrumentation Labs
Test Stands
Process Monitoring
Vibration & Shock Testing

TE CONNECTIVITY SENSORS /// MODEL 121 PRECISION LOW NOISE DC AMPLIFIER

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MODEL 121 PRECISION LOW NOISE DC AMPLIFIERPERFORMANCE SPECIFICATIONSParameters
INPUT SPECIFICATIONS
Input Range

Differential ±12Vdc or peak Vac

Input Connector

9-pin D-sub connector for each of the 3 channels

Input Impedance>1 Megohm minimum

Common Mode Input Range±12Vdc or peak Vac

Autozero Adjustment Range

The greater of ±100mVdc or ±10/gain

Autozero Accuracy

Within ±20mV , user actuate/de-actuate

OUTPUT SPECIFICATIONSAC/DC Voltage

Single ended, short circuit protected. User selectable for DC or AC measurement.

Output Connector

BNC connector for each channel for each of the 3 channels

Output Impedance

0.2 ohms max

Linear Output±10VpeakCurrent Output

20mA max

Excitation Voltage±12.5 Vdc dual or 0 to 25 Vdc single-ended, user selectable for each channel

Excitation Voltage Accuracy

The greater of ±1% or 50 mVdc

Excitation Current

30mA maximum per channel, short circuit protected

Shunt Calibration

User configurable to shunt any of the four legs of bridge. 150 kohm default value
for shunt.

TRANSFER CHARACTERISTICS
Gain Range

0 to 9999

Accuracy±0.5% of full scale

Linearity±0.1% of full scale

Noise20uVrms RTI plus 1mVrms RTO

Frequency Response

DC to 200 kHz

Low Pass Output Filter

User-installed plug in module (optional), enable/disable switch, two pole

Isolation

Channel to channel signal grounds not isolated, signal ground to case groundisolated

POWER REQUIREMENTS
Voltage

110/220V~ 50/60 Hz, auto-detects

PHYSICAL CHARACTERISTICS
Weight (w/o power cord)

8.2 lbs (3.7 kg)

Case Material

Aluminum

Dimensions (H x W x L)

4.0 x 10.2 x 11.8 inches (102 x 258 x 301 mm)

ENVIRONMENTAL
Temperature Range, Operating+32°F to +122°F (0°C to +50°C)

Temperature Range, Storage-40°F to +185°F (-40°C to +85°C)

Humidity<90%TE CONNECTIVITY SENSORS /// MODEL 121 PRECISION LOW NOISE DC AMPLIFIER

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MODEL 121 PRECISION LOW NOISE DC AMPLIFIER

ORDERING INFODESCRIPTIONPART NUMBER +POWER CORD OPTION

DC Amplifier
DC Amplifier
DC Amplifier

121-U
121-E
121-A

NEMA 5-15 USA 3 pin Plug (120V, 60Hz)
CEE 7/16 Europlug (220V, 50Hz)
AS-3112 China, Australasia (220V, 50HZ)

Optional Accessories
Filter Module, 20Hz, 4-Pole Low Pass
Filter Module, 100Hz, 4-Pole Low Pass
Filter Module, 1kHz, 4-Pole Low Pass
Filter Module, 10kHz, 4-Pole Low Pass
Filter Module, 20kHz, 4-Pole Low Pass
DB9 Connector

AC-A04542-020
AC-A04542-100
AC-A04542-1K0
AC-A04542-10K
AC-A04542-20K
AC-G03253

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Measurement Specialties, Inc., a TE Connectivity company.
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The information given herein, including drawings, illustrations and schematics which are intended for illustration purposes only, is believed to be reliable. However, TE Connectivity makes
no warranties as to its accuracy or completeness and disclaims any liability in connection with its use. TE Connectivity‘s obligations shall only be as set forth in TE Connectivity‘s Standard
Terms and Conditions of Sale for this product and in no case will TE Connectivity be liable for any incidental, indirect or consequential damages arising out of the sale, resale, use or
misuse of the product. Users of TE Connectivity products should make their own evaluation to determine the suitability of each such product for the specific application.
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All Rights Reserved.

TE CONNECTIVITY SENSORS /// MODEL 121 PRECISION LOW NOISE DC AMPLIFIER

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