The differential pressure indicates the pressure difference between two outputs irrespective of the line or static pressure. Its main characteristics are equivalent to relative pressure equipment except that it has two pressure connections. We must consider line or static pressure and the fluid to be measured because there are models that can only work with clean air and non-corrosive or oxidant gases (such as DMD341, DPS200 and DPS300) and others are compatible with a multitude of fluids such as DMD 331.
Transmitters with local display
They are pressure transmitters incorporating an electronic display control on the same computer. They may additionally have alarm contacts becoming presostatos.
This electronic allows us to visualize the pressure and in many cases adjust the value of the contact activating PNP or NPN signal to reach the set point.
The most common model is the MD831.
Smart transmitters
We call smart transmitters to those devices controlled by microprocessor and that incorporate the possibility to programme by HART protocol.
The model DPT200 a programmable range in scale 1:100 with nominal range between 10 mbar and 20 bar.
Output signal 4-20 mA + HART protocol. Accuracy 0,075% FSO. Aluminium case with optional display. Threaded connection + separators with flanged connection or sanitary process connections.