Leak Testing - Delfi P.T.S. Operator And Maintenance Manual

transducers is recorded at each of four set points, and these four calibration factors are used to correct the
signal from the pressure transducers during normal operation. The calibration factors are stored in memory.
EQUIPMENT REQUIRED:
•
Calibrated 0 to 500 mmHg pressure gauge.
•
Adjustable 0 to 500 mmHg pressure source.
•
Suitable pneumatic hoses and connectors.
CAUTION: The following steps must be taken in the exact order to calibrate the unit. Failure to do so
may result in incorrect pressure readings while the unit is in operation.
a) To enter the calibration mode, press and hold the 'INFLATE' and 'DEFLATE' buttons simultaneously, then
press 'ON/STANDBY' to switch the unit on. When the unit finishes its start-up sequence the unit will enter
the calibration mode and display "0" in the pressure display and alternating "CAL" and "0" in the time
display. This is to indicate to the user that the unit is now ready to calibrate. The time display indicates
the expected reference pressure to be applied to the cuff. The pressure display indicates the sensed
pressure.
b) With the hose connector on the P.T.S. unit open to atmosphere, press the 'PRESSURE + ' button to
indicate zero reference pressure is applied. The unit will adjust the transducer output corresponding to
zero pressure. The unit will then sound a tone to indicate that the reference pressure was taken.
c) Once the zero point is calibrated, press the 'TIME+ ' button to advance the unit to the next pressure level.
The time display will now be alternating between "CAL" and "50". Connect the P.T.S. to the reference
pressure source and gauge. Apply a calibrated reference pressure of 50 +/- 1 mmHg to the cuff port.
Once the pressure has stabilized, press the 'PRESSURE + ' button to indicate the reference pressure is
applied. The unit calibrates the 50mmHg point and sounds a tone when successfully completed. If the
reference pressure is more than 15 mmHg different from the sensed pressure, the unit shows "CAL" and
"Err" messages in the pressure and time displays respectively and halts the calibration routine. If this
happens, power off the unit and start over.
d) Repeat the preceding step for reference pressures of 250 +/- 1 mmHg and 475 +/- 1 mmHg. The unit will
not allow calibration points to be skipped.
e) Remove the reference pressure source and press the 'TIME- ' button three times to cycle the reference
pressure back to zero. The time display will alternate between "CAL" and "0". Press the 'INFLATE' and
'DEFLATE' buttons simultaneously to exit the calibration. The unit saves the new calibration values in
memory and displays "CAL" in both displays. Power off the unit by pressing the 'ON/STANDBY' button.

3.4 LEAK TESTING

Leak testing should be performed at least once every six months, or if leak alarms occur without an obvious
cuff or hose leak. The P.T.S. is capable of maintaining cuff pressure even with a substantial leak in the
system; however any leak may become worse and lead to loss of occlusion during a procedure, so it is
important to find and correct leaks as soon as possible.
a) Connect a leak-free Delfi Contour Lower Leg cuff, Contour Arm cuff, or a similar sized cuff to the P.T.S.
using the hose assembly.
b) Adjust the pressure set point to 475 mmHg.
c) Inflate the cuff and allow the pressure to stabilize.
d) Set the unit to standby as follows: Press the 'ON/STANDBY' button until the alarm message "CUFF NOT
DEFLATED" appears. Release the 'ON/STANDBY' button and within 5 seconds of the alarm
discontinuing, press and hold the 'ON/STANDBY' button again. Hold the button in for 10 seconds. The
unit will switch to standby. NOTE: During the 10 seconds, the alarm message will be displayed, the
alarm will continue to sound and cannot be silenced.
e) Wait for 10 +/- 1 minutes and turn the unit back on. Operation will resume with a "PRESSURE" alarm
(See 'Cuff pressurized during power up' condition, Table 2.1).
'PRESSURE+ ' button to cancel the alarm and display the new pressure set point (shown with a trailing
asterisk). The set point should be at least 400 mmHg.
Momentarily press and release the
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