Dual Mode Constant Voltage & BCC Excitation

Precision 28000 Solutions for Measuring Bridges, Static and Dynamic Strain, RTDs, IEPE Sensors and Other Resistance Based Sensors

Precision’s line-up of quad-channel conditioners provide the versatility to condition a wide variety of constant voltage excited sensors including full bridges and sensors that require precise bridge completion. Use the Balanced Constant Current™ (BCC™) excitation technology to measure 2 or 4-wire dynamic or static resistance measurements for strain gages, RTDs and other resistive sensors. Choose the full-featured high performance 28144 card, the 28124 card for multiple filtered/wideband outputs or the 28114 for the best value.

Programmable bridge configuration and shunt calibration are supported via options HC10 and HC14, which are available on the 28124 card. The HC14 configuration option supports measurements of strain in a ¼, ½ or full bridge configuration with 255-step bipolar shunt calibration. Precise low drift completion resistors are included for 120, 350 or 1000 ohm bridges. The HC14 also supplies an 8mA current source for measurements with IEPE transducers.

The HC10 Bridge/RTD/Thermocouple/Voltage Configuration Module option supports full-bridge, RTD and thermocouple measurements. A 1mA precision constant current excitation is supplied to the RTD. Current drive and signal sense terminals are available on the input connector to allow a 4-wire Kelvin connection to the RTD. Precision RTD substitution resistors are supplied for calibration purposes. Precision thermocouple DC input voltage substitution is provided. For full bridge measurements, programmable single-step bipolar shunt of R1 or R2 is supported. In addition, relay contacts are used to connect the sensor internal cal resistor (if equipped) to ±excitation.

All cards feature “on-the-fly” reporting of measured sensor excitation and resistance. In constant current mode, the excitation current source output may be modulated to allow AC current injection in the loop. The frequency and amplitude of the AC current is user controlled. This allows the user to simulate changes in gauge resistance in the loop and provides direct AC input stimulation to the signal conditioner for end-to-end system calibration. The 28124 card introduces AC shunt calibration, a technique to shunt the bridge with a voltage-controlled resistor, allowing the user to evaluate the frequency response of a bridge-based sensor interacting with the cable capacitance.

The 28144, 28114 and the 28124 are members of the Precision 28000 family of signal conditioners.

The 28000 Signal Conditioning System

Learn more about the 28000 Signal Conditioning System >

  • The 28000 Static or Dynamic Strain Signal Conditioning Cards.

    The 28000 Dual Mode Constant Voltage & BCC Excitation Signal Conditioning Cards.

    MEASUREMENTS:

    • Dynamic Strain Gage
    • Static Strain Gage
    • Full Bridge and Other Bridge Configurations
    • Piezo-resistive Pressure Sensors (Kulite)
    • Piezo-resistive Accelerometers
    • IEPE Sensors
    • Resistance Temperature Detectors (RTD)
    • Load Cell Sensors
    • MEMS Transducers
    • Hot Wire Anemometry
    • AC or DC Filter/Amplifier

Dual Mode Bridge and Dynamic Strain Features:

28144 4-Channel Wideband Transducer Conditioner Features:

  • Four channels per card, 64 channels per 28016 chassis
  • Balanced programmable constant voltage excitation with remote sense – up to 20 V delivered to the bridge
  • REZCOMP™ technology to extend frequency response of accelerometer, unsteady pressure and microphone sensor measurements
  • Balanced differential constant current excitation (20 mA/20 V compliance) with AC current test mode for verifying transducer, cabling and frequency response
  • On-the-fly report of measured transducer excitation and resistance
  • Transducer open/short indication
  • Transducer leakage resistance measurement in constant current excitation mode, Option L
  • Automatic bridge balance/transducer suppress
  • Up to 204.6 kHz “filtered” bandwidth or 500 kHz “wideband” bandwidth
  • 2 to 10-wire plus shield bridge input interface
  • 2 or 4-wire input plus shield transducer interface with constant current excitation
  • Programmable AC/DC input coupling
  • Programmable gain: x1/16 to x8192 with 0.05% vernier
  • 4 or 8-pole low-pass filters with programmable FLAT/PULSE characteristics
  • Overload detection
  • Precise digital calibration
  • Programmable 5000 step (BC6 completion module) or single step (BC7 completion module) bipolar shunt cal
  • Programmable bridge configuration: 1-arm, 2-arm or 4-arm bridges
  • Programmable bridge resistance: 120 ohms, 350 ohms or 1 kohms
  • Front panel connectors that accept output adapter modules for multiple buffered outputs per channel

View the 28144 4-Channel Wideband Transducer Conditioner Specification Sheet >

28114 4-Channel Transducer Conditioner Features:

  • Four channels per card, 64 channels per 28016 chassis
  • Balanced programmable constant voltage excitation with remote sense – up to 20 V delivered to the bridge
  • Balanced differential constant current excitation (20 mA/20 V compliance) with AC current test mode for verifying transducer, cabling and frequency response
  • On-the-fly report of measured transducer excitation and resistance
  • Transducer open/short indication
  • Transducer leakage to ground detection
  • Automatic bridge balance/transducer suppress
  • Up to 30 kHz “filtered” bandwidth or 190 kHz “wideband” bandwidth
  • 2 to 10-wire plus shield bridge input interface
  • 2 or 4-wire input plus shield transducer interface with constant current excitation
  • Programmable AC/DC input coupling
  • Programmable gain: x1/16 to x1024 with 0.05% vernier
  • 4-pole low-pass filters with programmable FLAT/PULSE characteristics
  • Overload detection
  • Precise digital calibration
  • Programmable 5000 step (BC6 completion module) or single step (BC7 completion module) bipolar shunt cal
  • Programmable bridge configuration w/BC?: 1-arm, 2-arm or 4-arm bridges
  • Programmable bridge resistance w/BC?: 120 ohms, 350 ohms  or 1 kohms
  • Front panel connectors that accept output adapter modules for multiple buffered outputs per channel

View the 28114 4-Channel Transducer Conditioner Specification Sheet >

28124 4-Channel Wideband Transducer Conditioner Features:

  • Four channels per card, 64 channels per 28016 chassis
  • Three wideband or filtered outputs per channel
  • Balanced programmable constant voltage excitation with remote sense – up to 20 V delivered to the bridge with AC shunt calibration test mode for verifying transducer, cabling and measurement system frequency response
  • Balanced differential constant current excitation (0-20 mA/20 V compliance) with AC current cal test mode for verifying transducer, cabling, and frequency response
  • Option HC10 – RTD/Bridge/Thermocouple Configuration. 4-Wire 0-1 mA RTD excitation. RTD substitution, Thermocouple substitution (1 mV — 100 mV) and resistive shunt cal.
  • Option HC14 – Bridge/Strain/IEPE Configuration. Prog. Bridge Configuration (1, 2, 4-Arm) or 2-Wire/4-Wire Constant Current. Prog. Completion (120, 350 and 1kOhm). Programmable Precision 255 Step Bipolar Resistive Shunt Calibration of R1 or R2. IEPE input mode (8 mA constant current source).
  • On-the-fly report of measured transducer excitation and resistance
  • Transducer open/short indication
  • Transducer leakage resistance measurement in constant current excitation mode
  • Automatic bridge balance/transducer suppress
  • Up to 100 kHz “filtered” bandwidth or 250 kHz “wideband” bandwidth
  • 2 to 10-wire plus shield bridge input interface
  • 2 or 4-wire input plus shield transducer interface with constant current excitation
  • Programmable AC/DC input coupling
  • Programmable gain: x1/16 to x8192 with 0.01% resolution
  • 4 -pole low-pass filters with programmable flat/pulse characteristics
  • Prefilter overload detection
  • Precise digital calibration

View the 28124 4-Channel Wideband Transducer Conditioner Specification Sheet >

28144, 28114 and 28124 Dual Mode Constant Voltage & BCC Excitation Comparison Chart

Card

28144

28114

28124

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

Channels/Card

4

4

4

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

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

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

Bandwidth

500 kHz

190 kHz

250 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

Filter

4-Pole Low-Pass with optional REZCOMP, 8-Pole Low-Pass or 8-Pole Band-Pass

4-poles; FLAT/PULSE LP

4-poles; FLAT/PULSE LP

Cut Off Frequencies

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

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

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

Outputs

Single Ended with Ground Reference

Single Ended with Ground Reference

(3) Buffered Prog WB/Filtered SE Outputs per Channel w/ Ground Reference

* 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-Pole Low-Pass with optional REZCOMP, 8-Pole Low-Pass or 8-Pole Band-Pass

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:
100 Hz to 25.5 kHz PULSE:
50 Hz to 12.75 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.