Introduction – Fluke Biomedical BP Pump 2 User Manual
Page 39
Operation
Introduction
3
3-3
Introduction
The Tester contains a microprocessor that reads and controls the front panel
keyboard, the display, serial port, printer port, a diaphragm pump, two solenoid
valves, a step motor, a position sensor, and a pressure transducer (Figure 3-1).
Filter
Step
Motor
Home
Position
Sensor
Lead Scre
w
and Piston
Option
Rolling
Seal
Ring
St
u
d
N
.C. Solenoid
V
al
v
e
Front Panel
Press
u
re Port
V
ent/Zero Port
Internal Ad
u
lt
C
u
ff
V
ol
u
me
290cc
1
2
Ring
St
u
d
N
.C. Solenoid
V
al
v
e
1
2
Hi Acc
u
racy
Press
u
re
Sensor
Standard
Press
u
re
Transd
u
cer
Check
V
al
v
e
DC
Diaphragm
P
u
mp
fas14.eps
Figure 3-1. Tester Pneumatic Block Diagram
The diaphragm pump is used as a pressure source for the relief valve, leak, and
pressure source tests. The diaphragm pump pulls air through a filter and forces it
through a check valve into the main manifold of the instrument. This main
manifold has an internal volume of approximately 20 cc and is directly connected
to the pressure port on the front panel. Pressure in the manifold is measured by a
pressure transducer and can be released by a solenoid-operated valve. The volume
of the main manifold can be increased by approximately 290 cc, to simulate an
adult pressure cuff, by opening a second solenoid valve.
A stepper motor and lead screw move a piston into the manifold to decrease the
manifold volume, thereby creating pressure pulses to simulate a human subject. A
seal around the piston is maintained by a rolling diaphragm seal. The size and