The following information is for the EMANT300, EMANT380
BRIDGE COMPLETION NETWORK
The
Bridge Completion Network is used to complete quarter and half bridge
strain gauge circuits.
FEATURES
- Three 120 ohm resistors
- Tolerance: 0.1%
- Temperature Coefficient: +/- 25ppm
- Power Rating: 0.1W
- Screw Terminals for easy connection.
STRAIN GAUGE
A strain gauge can be used to measure the strain of an object. The most common type of strain gauge consists of a flexible backing which
supports a metallic foil pattern etched onto the backing. As the
object is deformed, the foil pattern is deformed, causing its
electrical resistance to change. The gauge factor of a strain gauge
relates strain to change in electrical resistance. The gauge factor
GF is defined by the formula
where RG is the resistance of the undeformed gauge, ΔR is the change in resistance caused by strain, and ε is strain. ΔR is typically in the region of 0.1%. To measure such small resistance changes, a Wheatstone bridge is employed. 3 configurations are used - quarter bridge, half bridge or full bridge. Resistors are used to form the bridge in the quarter bridge and half bridge.
Quarter Bridge Connection
Fig 1: Connecting the strain gauge to the network and Bridge Sensor Adaptor
Strain ε is given by
where
and ΔVO is the change in voltage output of the wheatstone bridge from strained to unstrained (seen at the differential input AIN3, AIN2). VEXC is the excitation voltage.
Half Bridge Connection
Fig 2: Connecting the strain gauges to the network and Bridge Sensor Adaptor
Strain ε is given by
Schematic
Specification (PDF file size 355K)
Price US$8
Status Discontinued
The schematic and PCB layout in Eagle format is available for download. Note that the information is provided AS-IS and no further support is available. It is intended for those familiar with electronics and Eagle PCB layout.