Simple and compact pressure measurement

The well-established Beckhoff Bus Terminal system is being expanded by the new pressure measuring terminals, KM37xx for recording differential and absolute pressures. In a similar way to electrical signal acquisition, pressure measurement is carried out using a “standard” Bus Terminal with a width of only 24 mm. The compact housing and simple connection system support a space-saving and rapid installation. Additional measuring instruments are not necessary.

The pressure measuring terminals record direct differential and absolute pressures and change the measured pressure into an electrical signal. This 16-bit value is available to the higher level controller independent of the fieldbus. The pressure measuring terminals have quick release mechanisms for connecting the measuring hoses. Standard commercial plastic hoses can be used as the measuring hoses. In addition to measuring, the Bus Terminals also execute other functions such as temperature compensation and avoidance of long-term drift.

Three different pressure measuring terminals are available:
– KM3701: The 1-channel differential pressure measuring terminal measures pressure differences up to an ambient pressure of
7,000 hPa (7 bar) between points.
– KM3702: The 2-channel absolute pressure measuring terminal records pressure values between 0 and 7,000 hPa (7 bar) at each hose connector.
– KM3712: The 2-channel absolute pressure measuring terminal records negative pressure values between -1,000 hPa (-1 bar) and 0 hPa at each hose connector.

Beckhoff pressure measuring terminals can be used in any situation that requires the measurement and monitoring of differential and dynamic pressures in nonaggressive gases, e.g. in pressure tanks, pressurized cabins, pneumatic and suction systems. They measure operating pressures, monitor filters and sieves, check the seal tightness of tanks and assist in position testing of construction elements or monitoring the level of liquids. If flow rates are calculated from the measured pressures, then the KM37xx can also be used for flow measurement. They can therefore be applied in areas such as process engineering, systems engineering, building services as well as heating, ventilating and air conditioning.

Pressure measurement directly in the Bus Terminal system: With the pressure measuring Bus Terminals of the KM37xx series differential and absolute pressures can be recorded directly in the I/O system – without further measuring instruments.

Courtesy of  Beckhoff