Absolute pressure measures the pressure relative to vacuum.
Pressure sensors can have different technologies.
Ceramic pressure sensors with thin layer.
They are made with a ceramic base and ceramic membrane following the piezoresistive principle.
The membrane has a Wheatstone bridge that It becomes imbalanced by deforming the membrane due to the pressure being proportional to the pressure deviation received.
Capacitive ceramic sensors
Are built with a ceramic membrane following the capacitive principle, in the pressure measurement occurs variation of capacitance due to deformation of the plates of a capacitor. The plate condenser is screenprinted on the membrane.
These sensors have a high rupture pressure and excellent chemical resistance.
Stainless sensors
Based on a pressure sensitive chip, incorporates a membrane of stainless isolation that allows direct application with aggressive fluids and oxidants.
Relative pressure transducers can be applied in a wide range of fields. SENSOTEC Instruments has devices or low pressure measurement with standard ranges between 0 to 0,1 mbar and 0 to 400 mbar. We also have transmitters like the DMP 331 or the DMK 331.
Pressure transmitters built with different are available with analogic output (0 to 10 v, 1 to 5 V, 4-20 mA, etc.) digital output (RS485, HART protocol, etc.).
It is also possible to have several process (1/4”, ½”, 1”, flanges, etc.) and electric connections (DIN, cable, M12, etc.) that suit most market requirements.
Regarding accuracy, we offer standard accuracy devices 0,5% FE up to 0,075%L.
Materials in contact with the fluid (stainless, PVDF, etc.) and the different bodies with protection IP65 to IP68 meet expectations for the most demanding applications.
Transmitters with local display
They are pressure transmitters incorporating an electronic display control on the same computer. They may additionally have alarm contacts becoming switches.
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 models are the DS200, DS201 and DS400.
Smart transmitters
We call smart transmitters to those devices controlled by microprocessor and that incorporate the possibility to programme by HART protocol.
The series XMPi (stainless sensor) and XMP Ci (ceramic sensor) have a programmable range in scale 1:10 with nominal range between 60 mbar and 600 bar.
Output signal 4-20 mA + HART protocol. Accuracy 0,1% FSO. Aluminium case with optional display. Threaded connection by flange or sanitary connections.
Available in ATEX EXia or Exd.