Bridge Conditioners with Voltage Excitation

Precision 28000 Solutions for Bridge and other Transducers Requiring Constant Voltage Excitation

Where applications call for high performance, high channel-density bridge conditioning, the 28108 and 28118 octal filter/amplifiers with constant voltage excitation deliver low-noise and DC stability for either AC or DC bridge-based sensor or low-level voltage measurements. Stable and accurate balanced constant voltage excitation with remote sense is individually regulated and programmable per channel. Low-noise and low-drift amplification is distributed before and after the low-pass filter, providing protection against out-of-band noise. FLAT/PULSE low-pass filter technology with outstanding channel-to-channel matching for correlation measurements. Fully programmable filter cutoff frequencies with filter bypass for wideband measurements.

The 28108 provides low noise, high CMRR performance with gain settings from x1/16 to x8192 and 255 unique cutoff frequencies. The lower cost 28118 has gain settings from x1/16 to x1024 with five programmable cutoff frequencies.

The 28108 and the 28118 are members of the Precision 28000 family of signal conditioners.

The 28000 Signal Conditioning System

Learn more about the 28000 Signal Conditioning System >

  • The 28108 and the 28118 Bridge Conditioners with Voltage Excitation

    The 28108 and the 28118 with Option 4 Bridge Conditioners with Voltage Excitation

    APPLICATIONS:

    • Underwater Acoustics
    • Pyroshock Measurements
    • Ballistics
    • Vehicle Vulnerability/ Survivability
    • Rotating Machinery Test
    • Automatic Test Equipment
    • Industrial Process Control
    • Anti-aliasing Filter/Amplifier

    TRANSDUCERS:

    • Strain Gage
    • Static/Dynamic Pressure Transducers
    • Piezoresistive Accelerometers
    • Resistance Temperature Detectors (RTD)
    • MEMS Sensors
    • Load Cell Sensors

Bridge Conditioners with Voltage Excitation Features:

28108 8-Channel Bridge Conditioner Features:

  • Eight channels per card, 128 channels per 28016 chassis
  • Balanced differential inputs with 2 to 6-wire plus shield transducer input interface.
  • Balanced (zero common-mode) programmable constant voltage excitation. Up to 20V delivered to the bridge.
  • Automatic bridge balance/Zero suppress via a programmable DC voltage inserted at the channel input
  • Distributed programmable gain of x1/16 to x8192 with 0.05% resolution
  • Input MUTE mode to terminate unused channels in safe, quiet state
  • Pre-filter overload detection
  • 4-pole low-pass filters with programmable flat/pulse characteristics for optimized time domain or frequency domain performance. Programmable low-pass filter cutoff frequencies:
    Pulse Mode: Programmable from 50 Hz to 12.75 kHz
    Flat Mode: Programmable from 100 Hz to 25.5 kHz
  • wideband (100 kHz) or filtered operation
  • Precise digital calibration
  • Single-ended outputs with ground sense or optional differential output
  • Programmable test modes for cal signal injection, excitation monitor, excitation off and input short, allowing for automated measurement system validation
  • Output monitor bus
  • Auxiliary front panel output connection supports the use of Precision Filters’ output buffer modules for adding up to two buffered outputs per channel (for units without option 4)

View the 28108 8-Channel Bridge Conditioner Specification Sheet >

28118 8-Channel Bridge Conditioner Features:

  • Eight channels per card, 128 channels per 28016 chassis
  • Balanced programmable constant voltage excitation with remote sense
  • Up to 20 V delivered to the bridge
  • ±10 Vcm operation
  • Up to 30 kHz “filtered” bandwidth or 190 kHz “wideband” bandwidth
  • 2- to 6-wire plus shield transducer input interface
  • Automatic bridge balance/transducer suppress
  • Programmable amplifier: x1/16 to x1024 with 0.05% vernier
  • Distributed gain to provide reserve against out-of-band signal such as transducer resonances
  • 4-pole low-pass filters with programmable flat/pulse characteristics
  • 2° phase matching between any channels
  • Overload detection
  • Auxiliary front-panel output connection to support the use of custom output modules (for unit without option 4)

View the 28118 8-Channel Bridge Conditioner Specification Sheet >

28108 and 28118 Comparison Chart

Card

28108

28118

Type

AC/DC Voltage, Bridge,
Static Strain, Dynamic Strain

AC/DC Voltage, Bridge,
Static Strain, Dynamic Strain

Channels/Card

8

8

Applicable Transducer

Static Strain, Pressure,
RTD, Load, Accelerometer, AC/DC Filter/Ampifier, any Full Bridge Type Sensor

Static Strain, Pressure,
RTD, Load, Accelerometer, AC/DC Filter/Ampifier, any Full Bridge Type Sensor

Interface

2 to 6 Wire w/ Shield

2 to 6 Wire w/ Shield

Excitation

Constant Voltage:
0 to 20.475 V

Constant Voltage:
0 to 20.475 V

Bandwidth

100 kHz

190 kHz

Gain

x1/16 to x8192 w/ 0.05% Resolution

x1/16 to x1024 w/ 0.05% Resolution

Filter

4-Pole, FLAT/PULSE Low-Pass

4-Pole, FLAT/PULSE Low-Pass

Cut Off Frequencies

FLAT: 2 Hz to 204.6 kHz
PULSE: 1 Hz to 102.3 kHz

FX02: 300, 1k, 3k, 10k, 30 kHz*

Outputs

Single-ended or Differential Output
(Option T)

Single-ended or Differential Output
(Option T)

* Custom cutoff frequencies are available. Please consult factory.

Bridge and Strain Conditioner Card Selection Guide

Card

28144

28114

28124

28108

28118

28458

Type

AC/DC Voltage, Bridge, Static Strain, Dynamic Strain

AC/DC Voltage, Bridge, Static Strain, Dynamic Strain

AC/DC Voltage, Bridge, Static Strain, Dynamic Strain

AC/DC Voltage, Bridge, Static Strain

AC/DC Voltage, Bridge, Static Strain

AC Voltage, Dynamic strain

Channels/ Card

4

4

4

8

8

8

Applicable Transducer

Static or dynamic strain, pressure, RTD, load, accel, AC/DC filter/amp, any bridge type sensor

Static or dynamic strain, pressure, RTD, load, accel, AC/DC filter/amp, any bridge type sensor

Static or dynamic strain, pressure, RTD, load, accel, AC/DC filter/amp, any bridge type sensor

Static strain, pressure, RTD, load, accel, AC/DC filter/amp, any full bridge type sensor

Static strain, pressure, RTD, load, accel, AC/DC filter/amp, any full bridge type sensor

Dynamic strain, AC/DC filter/amp

Interface

2-10 Wire Constant Voltage w/ Programmable Bridge Completion, Shunt Cal,

2/4 Wire Constant Current

2-10 Wire Constant Voltage w/ Programmable Bridge Completion, Shunt Cal,

2/4 Wire Constant Current

2-10 Wire Constant Voltage w/ Programmable Bridge Completion, Shunt Cal,

2/4 Wire Constant Current

2 to 6 wire w/ Shield

2 to 6 wire w/ Shield

2 wire w/ Shield

Excitation

Constant Voltage:
0 to 20.475V; Balanced Constant Current:
0 to 20.475mA

Constant Voltage: 0 to 20.475V; Balanced Constant Current:
0 to 20.475mA

Constant Voltage: 0 to 20.475V; Balanced Constant Current:
0 to 20.475mA

Constant Voltage: 0 to 20.475 V

Constant Voltage: 0 to 20.475 V

Balanced Constant Current: 0,5,10,15,20 mA

Bandwidth

500 kHz

190 kHz

250 kHz

100 kHz

190 kHz

190 kHz

Gain

x1/16 to x8192 w/ 0.05% Resolution

x1/16 to x1024 w/ 0.05% Resolution

x1/16 to x8192 w/ 0.05% Resolution

x1/16 to x8192 w/ 0.05% Resolution

x1/16 to x1024 w/ 0.05% Resolution

x1/16 to x1024 w/ 0.05% Resolution

Filter

4, 8-poles; FLAT/PULSE
Low-Pass or BP

4-poles; FLAT/PULSE
Low-Pass

4-poles; FLAT/PULSE
Low-Pass

4-Pole; FLAT/PULSE
Low-Pass

4-Pole, FLAT/PULSE
Low-Pass

4-Pole; FLAT/PULSE
Low-Pass

Cutoff Frequencies

FLAT:
2 Hz to 204.6 kHz PULSE:
1 Hz to 102.3 kHz

FX02: 300, 1k, 3k, 10k, 30 kHz*

FLAT:
2 Hz to 204.6 kHz PULSE:
1 Hz to 102.3 kHz

FLAT:
2 Hz to 204.6 kHz PULSE:
1 Hz to 102.3 kHz

FX02: 300, 1k, 3k, 10k, 30 kHz*

FX02: 300, 1k, 3k, 10k, 30 kHz*

Outputs

Single ended with Ground Sense

Single ended with Ground Sense

(3) Buffered Prog WB/Filtered SE Outputs per channel w/ Ground Sense

Single-ended or Differential Output (Option T)

Single-ended or Differential Output (Option T)

(2) Buffered Single-Ended Outputs per Channel

* Custom cutoff frequencies are available. Please consult factory.