Editor’s note: This is the second in a three-part series on air gauging. Engineer and inventor Michele Dechape has updated the seminal work on the subject by V. R. Burrows. Read part one here.

The circuit shown in figure 7a is a differential back-pressure circuit in which accuracy is maintained regardless of some variation in the regulator performance that controls supply pressure. This is now obsolete.

Figure 7b shows a differential back-pressure circuit with solid-state differential pressure transducer, which is the gold standard of differential back-pressure air electronic converters.

Figure 7a: Differential back-pressure circuit (Burrows figure)

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