109.The distance between top and bottom tapping in a drum for level measurement using DP transmitter is 1200mm. There are 600 mm apart from center of drum. The normal water level will be 250mm below the center line. The span of the level indicator is plus or minus 250 mm. What will be the calibration range of the dp transmitter?

The minus pressure from Drum minimum level to the constant column vessel middle is 4 mA.

 Ie., minus 1100 mm of WCL – 4 mA                                                                                  

The minus pressure from the drum maximum llevel to the contant column vessel middle is 20 mA.

Ie. Minus 600 mm WCL – 20 mA.