Zeroing a transducer
Figure 3a. Three way tap connecting vessel in patient to transducer. The system is not zeroed yet and the measurement of the pressure is not accurate.
Figure 3b. To zero the line, the 3-way tap at the transducer is opened so that the transducer is exposed to atmospheric pressure. The ‘zero pressure’ button is pressed on the monitor (thus the monitor has a reference for pressure that equates to zero).
Figure 3c. The 3-way tap is then turned to read the patients pressure. This time the measurement is accurate because it is done after the system has been zeroed.