Selecting bridge resistances for strain gauge

Discussion in 'General Electronics Chat' started by aamirali, Mar 22, 2014.

  1. aamirali

    Thread Starter Member

    Feb 2, 2012
    I am learning quarter-bridge strain gauge.
    Now how to select bridge resistance so that I can get 2mV/V or 5mV/V & so on.

    My strain gauge resistance is 1000ohm.
  2. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
    What are the manufacturers specifications for your 1000R strain gauge.?

    ie: mVolt output at its rated excitation voltage, max load etc.??

  3. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
    What is the model of strain gauge?
  4. aamirali

    Thread Starter Member

    Feb 2, 2012
  5. t06afre

    AAC Fanatic!

    May 11, 2009
    The guage resistance is something that construction of the guage it self decide. Strain guages need an excitation voltage. So as long as the latter exitation source can deliver enough current to "drive" the guage you OK
  6. aamirali

    Thread Starter Member

    Feb 2, 2012
    As given in datasheet strain is 1K , gauge factor = 2 & max starin = 30000E-6.

    So considering gauge factor and microstrain, total %age change in resistance = 2*30000E-6 = 6%.
    So change in resistance = 60ohm

    1. I have to conect starin in bridge mode where I will give excitation voltage to get desired ouput like 2mV/V or 10Mv/V.
    How to select that.

    2. On what load I will get maximum strain for current selected strain. Datasheet says 30000 microstrain but on what kilogram of load???

    3. Since I have selected strian with 1K resistance so I have kept othree three arm resistance also to 1K. So current drawn is above 4mA
    But my circuit is battery operated so what should I do in this case. Increase other bridge arm resistances????
    How to select arm resistances for minimum power consumption & zero output at no load.