hi i am using a lockin amplifier for the 1st time other than a canned college lab demo. i have a 5mV signal from a strain gage that is driven with 10Vpp at 1kHz or whatever i choose. the 5mV is increased to 5.01mV when i add some weight to the arm the gage is weighing. i wanted to increase sensitivity of this reading with the LIA since there is noise in the next digit, i.e. i read 5.01mV +- 0.01mV. But i seem to go out of range (overload) before reading any weight change. do i need to get a 0V average signal first, and put this into the LIA? the 4 strain gages are in a full wheatstone bridge configuration. The 10V 1kHz signal is sent to the bridge and to the LIA 'reference' input, 5mV 1kHz bridge output sent to to LIA signal in. I adjust the LIA phase for max output, zero the signal with the internal LIA offset, and increase sensitivity until i overload. then i back off the sensitivity so theres no overload. at this point i see no change in output with change in weight. the LIA sensitivity is generally 30mV at this point, whereas the signal I want to measure is 0.01mV or less, so it seems natural i wont get a change in output. the only thing i can think of is i must 'balance the bridge' to get 0.00V output, and amplify this to higher levels e.g. at the 0.01mV level. is this right?