>What is zero suppression and elevation in differential pressure measurement?
I think what you are referring to is biasing the signal to account for a zero offset.
An example would be using a DP transmitter to measure the level of a steam condensate tank, lets say its 120" tall. Typically you would connect the HP tap to the bottom of the tank and the LP tap to the top of the tank.
What happens is the steam condenses in the LP sensing line to give you a negative DP of 120" WC when the tank is empty so the zero is elevated 120" to read 0" WC as the tank fills up it then reads the correct level.
This is just one of many applications where you need to elevate the zero. another would be where you are trying to measure the density in a tank.
It used to be a real issue, sometimes you had to connect the transmitter backwards to get them to work but modern transmitters make it much easier.