Cussons P7300 Impulse Swirl Meter’s are designed to  measure swirl in the air flow drawn into an engine cylinder generated by the engine inlet port. Earlier methods of  measuring swirl such as swirl vane meters, were dependent
on the velocity profile of the air stream, whereas the  impulse type of meter overcomes this limitation by
responding to the total angular momentum flux in the  swirling air flow. The impulse swirl meter uses a swinging
honeycomb type matrix which is restrained from rotation  by a strain-gauged load cell to totally arrest the angular  swirl component thereby measuring the resultant angular impulse as a torque.

SPECIFCATION
The P7300 comprises a honeycomb matrix mounted within  a cylindrical housing, the dimensions of the individual cells
of the matrix being suitable for arresting the swirl of the  incoming air. The matrix is connected via a torque arm to a
strain gauge transducer which is calibrated by suspending  weights over pulleys either side of the torque arm.
The strain gauge transducer is rated at 220g, measured as a  positive or negative force; the length of the torque arm is  such as to enable torque values up to 1 x 10-1 Nm to be
measured. The unit can be arranged for flow in an upward  or downward direction and is supplied complete with  adaptor plate having a pilot bore of diameter 50 mm.
The P7302 display unit together with all the signal  conditioning boards is contained in a steel case complete  with carrying handle. If removed it can be mounted in a ½  rack case.
The front panel carries the 4 digit phosphorescent display, a mains on/off switch and zero and span potentiometers.

DESCRIPTION
The Aeroweb honeycomb matrix is suspended within a  cylindrical, aluminium housing with the skirt of the matrix
immersed in an annular oil reservoir in the base which  serves both as an air seal and a viscous damper. The matrix
is mounted on an axle in the frame and supported by precision ball bearings while the torque arm connected to the axle acts on a Wheatstone Bridge strain gauge transducer.
The unit is designed for blow or suction induced flow and can be assembled for operation in either the upward or downward mode, whichever is most convenient. A set of  weights is provided with the instrument to facilitate static calibration of the strain gauge with an accuracy of ±2%.
Cussons Display Unit P7302, used in conjunction with the swirl meter, is a mains operated instrument complete with power supplies, which converts the strain gauge measurement into a four element, LED digital readout.