Strain Bridge

Strain Bridge

Strain Bridge has high-contrast digital display gives a direct reading in micro-strains, for half or full bridge operation of the six channels. Measurements with a quarter bridge configuration can be made by adding a resistor. The gauge factor can be adjusted between 1 and 5. Each channel can be balanced separately by means of multiturn potentiometers. An analogue output for each channel permits the display of the signals using an oscilloscope or a plotter, and also data acquisition. With the bridge energisation of 2.5 V, strain gauges of 120 W minimum can be used. These can be in Constantan, Isoelastic Karma or Platinum - Tungsten alloys. The 20 000 point digital display allows measurements in the range ± 20 000 mm/m, whatever the gauge alloy.

Technical specifications

• Number of channels: 6.
• Operating range: ± 20 000 µm/m.
• Resolution: ± 1 µm/m.
• Bridge energisation: 2.5 V - Stability: 10-4.
• Gauge configuration: Full or half bridge with gauges of 120 to 5000 WQuarter bridge with additional resistor.
• Input impedance: 1010 W.
• Balance: using multi-turn potentiometers ± 2000 µW/W.
• Gauge factor read directly on display adjustable from 1 to 5 by multi-turn locking potentimeters.resolution: 0.001.
• Amplifier: precision 1 %.
• linearity: ± 0.002 %drift: 0.25µV/°C noise: less than 13µV per Hzcommon mode rejection:< 100 dB.
• Analogue outputs: independant output for the 6 channels, using Cannon 9 pin connectors max. output voltage: 10 V band pass: 0 - 10 kHz.
• 2 V for 20000 µW/W.
• Minimal load: 22000 W.
• Gauge connections: 15 pin Cannon connectors way rapid connector.

Option :

• Data acquisition and processing with an IBM-PC or compatible micro-computer, the system can configure and read the six channels simultaneously. It comprises three elements:

Software package

• Test identification.
• Strain bridge initialisation.
• Channel selection, gain, configuration (full or half-bridge), gauge factor, graph configuration, sampling rate, total number of acquisitions.
• Visualisation.
• Safeguard.
• Print-out.
• Saving test to file.
• Card-bridge connecting cable.
• Analogue / Digital acquisition card.

Features :

• Reads 16 single analogue inputs or 8 differential analogue inputs.
• 12 bit digital conversion, or a resolution of 4096 points full scale.
• Accepts maximum voltages of 0 to 10 volts in unipolar mode and ± 5 volts in bi-polar mode.
• Fixed frequency acquisition, through built-in time

Dimensions and weight

• 265 x 105 x 84 mm.
• Net weight : 1.8 Kg.

Essential requirements

• Voltage : 220 V, 50 or 60 Hz