Describe ratio metric conversion in brief.
Diagram:
Discription: It is a signal conditioning method applicable with DAS. It includes an analog voltage divider to which an excitation voltage is given as the input. The output of it is given to an instrumentation amplifier and then to A to D converter. The output voltage of the divider is the ratio of the amplifier output voltage and the excitation voltage. Thus by this method the output of the signal amplifier will be a voltage proportional to the input parameter only and independent of the input excitation voltage. Hence the system accuracy improves since variation in the excitation voltage does not affect the sensitivity of the system