The phase difference (positive or negative)
between the signals from each of the two infrared
receivers (RX1 and RX2) depends upon the direction
of rotation of the moving rotor and therefore supply
the information of the direction of the air flow
(expiration or inspiration).
In detail, > 0 for expiratory flow, < 0 for
inspiratory flow.
The two pulse trains are squared by a Schmitt trigger
(LMV932MM on MiniFlowmeter) and then sent to
two input ports of the microprocessor (IC17
CP3BT26, pins 38 and 36).
The main microprocessor has the possibility to switch
all the peripheral ports on or off, including the
turbine.
3. MAINTENANCE
3.1. GENERAL
We recommend checking the Spirolab on an annual basis.
For cleaning of the Spirolab
and the accessories please see the User Manual.
3.2. TEST EQUIPMENT
For the repair and maintenance procedures of the Spirolab the following test equipment and accessories are required:
- Complete set of precision engineering tools (including 2.5 mm allen key and cross-screwdriver)
- Calibration syringe (3L is recommended)
- Digital multimeter, at least 3½ digits, accuracy better than 1%.
- Oscilloscope
- Digital Thermometer
- PC
- winspiroPRO Software Installation CD
- USB port connection cable
- Oximeter sensor (MIR code 919024)
- Hot Glue Gun
- 3 mm double-sided adhesive tape
- Welder
If a problem cannot be solved with the present equipment and suitable instruments are not available, please send the
Spirolab to the manufacturer to carry out the service.
3.3. CHECKLIST
The following procedures must be carried out during an inspection and/or after every repair:
• Modifications, if any, must be noted on the “Service Info” sheets. See Appendix B of this manual for further
information.
• Visual inspection. Check the electrical connection for safety and check that all components are properly fastened.
• Check that all accessories do not present any visible damage.
• Functional test (see Paragraph 3.3.1)
• File a copy of all service activities.
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