190
5 Performance Measurement
The pump is connected to a suction reservoir with an 88.9 mm diameter pipe
and to a delivery reservoir with two 63.5 mm pipes. Upstream of the delivery reservoir are two bypass pipes that are opened when this reservoir gets emptied. The
pump then delivers directly into the suction reservoir. Suction and delivery pipes
are provided with control valves for adjusting the suction and delivery pressures.
The pump is driven by a DC motor with swinging suspended stator with lever arm
connected to a balance.
5.8.2 Measurements
The hydraulic power output follows from
• The suction pressure measured by a manometer in kgf/cm
2
(= 0.981 bar), read as
value below the atmospheric pressure.
• The delivery pressure measured by a manometer on each of the two delivery
pipes in kgf/cm
2
, read as value above the atmospheric pressure.
• The height difference between manometers at suction and delivery sides. The
manometers are provided with purge valves. Purging the pressure manometers
guarantees that the connecting pipe is filled with water. Purging the suction manometer guarantees that the connecting pipe is filled with air. A pressure manometer thus measures the pressure in the delivery pipe at the tapping point minus
the pressure corresponding to the height difference between the centre of the
manometer and the tapping point. The suction manometer measures the pressure
at the tapping point. The height difference to be taken into account between the
manometers is the distance from the tapping point of the suction manometer to
the centre of the pressure manometers. This amounts to 1.30 m.
• The flow rate by means of the calibrated delivery reservoir. The volume between
the gauge glass marks is 100 l. Choose the number of measured marks in proportion to the flow rate to be measured.
Mechanical power input follows from
• The rotational speed measured with an optical pulse tachometer (disc with holes).
• The torque on the driving motor with swinging suspended stator. The scale of the
balance is expressed in kgfm (= 9.81 Nm).
5.8.3 Measurement Procedure
• Select a rotational speed between 2000 and 2800 rpm. The driving motor is fed
by a direct current controller (right part of the cabin). The rotational speed is
5 Performance Measurement
The pump is connected to a suction reservoir with an 88.9 mm diameter pipe
and to a delivery reservoir with two 63.5 mm pipes. Upstream of the delivery reservoir are two bypass pipes that are opened when this reservoir gets emptied. The
pump then delivers directly into the suction reservoir. Suction and delivery pipes
are provided with control valves for adjusting the suction and delivery pressures.
The pump is driven by a DC motor with swinging suspended stator with lever arm
connected to a balance.
5.8.2 Measurements
The hydraulic power output follows from
• The suction pressure measured by a manometer in kgf/cm
2
(= 0.981 bar), read as
value below the atmospheric pressure.
• The delivery pressure measured by a manometer on each of the two delivery
pipes in kgf/cm
2
, read as value above the atmospheric pressure.
• The height difference between manometers at suction and delivery sides. The
manometers are provided with purge valves. Purging the pressure manometers
guarantees that the connecting pipe is filled with water. Purging the suction manometer guarantees that the connecting pipe is filled with air. A pressure manometer thus measures the pressure in the delivery pipe at the tapping point minus
the pressure corresponding to the height difference between the centre of the
manometer and the tapping point. The suction manometer measures the pressure
at the tapping point. The height difference to be taken into account between the
manometers is the distance from the tapping point of the suction manometer to
the centre of the pressure manometers. This amounts to 1.30 m.
• The flow rate by means of the calibrated delivery reservoir. The volume between
the gauge glass marks is 100 l. Choose the number of measured marks in proportion to the flow rate to be measured.
Mechanical power input follows from
• The rotational speed measured with an optical pulse tachometer (disc with holes).
• The torque on the driving motor with swinging suspended stator. The scale of the
balance is expressed in kgfm (= 9.81 Nm).
5.8.3 Measurement Procedure
• Select a rotational speed between 2000 and 2800 rpm. The driving motor is fed
by a direct current controller (right part of the cabin). The rotational speed is