A MAX1491 is a self contained DC Voltmeter that can drive an LCD display to 2000 counts.
Also, here in the US, you can buy inexpensive DC panel meters for about $10.00-$15.00 each.
I have used the following circuits to null out offsets on wheatsone bridge circuits. The first circuit just puts a resistor in parallel with one branch of the bridge allowing any offset to be adjusted out. R Offset value can be calculated by figuring out parallel resistance needed to compensate...
I have used the following attached schematic using a 7486 exclusive or (XOR) chip. It is basically a digital frequency doubler. It relies on the propagation delay of the second and third section to provide an output pulse. With Pin 1 High, the output (pin 11) will be High with a negative going...