Dynamic Strain with Current Excitation

Precision 28458 Solution for Measuring Dynamic Strain

Precision’s Balanced Constant Current™ technology is available in the high-density 8-channel 28458 card. Measurements of dynamic strain are much less susceptible to EMI pickup and lead resistance desensitization that plagues single-ended constant current topologies. The 28458 features Precision’s “on-the-fly” measurement of transducer resistance, excitation and leakage resistance, alerting the operator immediately to an out-of-tolerance condition. AC dither current provides for evaluation of true sensor plus cable frequency response. Fully programmable FLAT/PULSE filters with distributed gain for out-of-band noise protection.

The 28458 is a member of the Precision 28000 family of signal conditioners.

The 28000 Signal Conditioning System

Learn more about the 28000 Signal Conditioning System >

  • The 28458 Dynamic Strain Card with Current Excitation

    28458 8-Channel Conditioner with Balanced Constant Current Excitation

    MEASUREMENTS:

    • Dynamic Strain Gage Conditioner
    • High Temperature Strain Gage Conditioner
    • Dynamic Hot Wire Anemometry
    • AC/DC Filter/Amplifier

28458 8-Channel Conditioner with Balanced Excitation Features:

  • Eight channels per card
  • 128 channels per 28016-M3 or 28016-M5 mainframe,
    64 channels per 28008-M3/M5 mainframe,
    32 channels per 28004-M3/M5 mainframe
  • AC coupled balanced differential input
  • Balanced differential constant current excitation
  • Excitation disconnect for voltage/amp operation
  • 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
  • 4-pole flat/pulse low-pass filter (LP4FP) with cutoff options from 100 Hz to 100 kHz
  • Bypass filter for wideband amplifier operation (–3dB @ 190 kHz)
  • Voltage substitution test signals
  • Programmable amplifier: x1/16 to x1024 with 0.05% vernier
  • 2° phase matching between any channels
  • Pre-filter overload detector to report out-of-band overloads which the filter could mask
  • Dual buffered outputs

View the 28458 Specification Sheet >


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.