Shimmer3 Bridge Amplifier+ Unit

Shimmer3 Bridge Amplifier+ Unit

Shimmer3 Bridge Amplifier+ Unit

Shimmer3 Bridge Amplifier+ Unit

The Bridge Amplifier+ unit allows for a new range of sensors to be connected to the Shimmer3 platform. The unit allows for strain and load cell data acquisition for force and resistance measurement. The module contains a bridge amplifier, excitation source and connector enabling force measurement with the Shimmer, as well as a buffered resistance divider amplifier to enable resistance measurements.

The Bridge Amplifier+ module is ideal for all load, weight, force, torque and pressure measurements and the resistance divider input is suitable for variable resistance sensors, such as a temperature probe.

 

 

Features & Benefits

Specific Features

  • Interface strain gauge or load cell sensors with Shimmer3 to measure load, weight, force, torque or pressure
  • Interface variable resistance sensor with Shimmer for example, temperature sensitive resistor to measure ambient, skin-surface or other temperatures
  • Provides excitation source for strain gauge or load cell, meaning no external voltage source is required
  • Excitation source and amplifier enable are software controlled, allowing optimisation of power consumption
  • Two channels of output from bridge amplifier, providing both low and high gain; low gain is ideal for bipolar inputs, whilst high gain provides additional 3x gain for unipolar load cells
  • EEPROM storage device enables expansion board detection and identification, as well as 2032 bytes of data storage available to user.

 

Benefits over previous generation Strain Gauge

  • Bridge Amplifier input for Strain Gauge as well as resistance divider input
  • Strain Gauge/Resistance data can be measured simultaneously with 10DOF kinematic data
  • Record temperature of skin-surface or ambient temperature with Shimmer3
  • Now has use of an on-board EEPROM allows automatic identification of the expansion board

 

 

Specifications

Bridge Amplifier+ Unit Includes:

Shimmer3 Bridge Amplifier+ unit x 1

Skin surface temperature pack x1 (3 ina pack)

TTRS pack x 1 (6 in a pack)

Bridge Amplifier Specification overview

  • Gain :183.7 ± 1% (Normal Channel), 551 (3x Normal) ± 1% (High Gain Channel)
  • Frequency Range1: DC..1kHz (Normal Channel), DC..100Hz (High Gain Channel)
  • Common Mode Rejection1:  higher than 110dB
  • Input Impedance1: 50MOhm
  • Input Signal Range: ±7mV, ±2.5mV/V (Normal Channel), 0-4mV, ±1.43mV/V (High Gain Channel)
  • Zero-load Noise: 12mV RMS both outputs, < 1% full-scale (Normal Channel), < 0.5% full-scale (High Gain Channel)
  • Excitation Voltage: 2.8V ± 5%
  • Input Protection: Current limiting, EMI/RF suppression

Resistance Amplifier

  • Gain1: 10.1 +/-2%
  • Pull-up/Input Impedance:  200kOhms to +3.0V
  • Frequency Range1:  DC..408Hz (2nd Order)
  • Signal Range: 280mV or 20kOhms (1k­­Ω-20kΩ measurement range recommended)
  • Zero-load Noise: 0.1 mV RMS at ouput.

 

  • Connections: Two 3.5mm jacks (headphone type) for 4 conductor shielded cable for Bridge Amplifier and Resistance Amplifier,
  • Current Consumption: < 100µA (Excitation disabled), 17mA  (Excitation enabled).
  • Compact Dimensions 65X32X12mm
  • EEPROM memory: 2048 bytes 

Applications

  • Strength, capacity and force measurement
  • Resistance measurement
  • Rehabilitation
  • Sports training
  • Environmental monitoring
  • Fall risk assessment (grip strength)

Video