13 - Testing and fine tuning
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Testing flow transducer
• BROWN wire to positive of 12 volt battery.
• BLACK wire to negative.
• BLUE wire to multimeter positive.
1. Check the rotor turns freely.
2. Each vane in the rotor has a magnet in it with the pole facing out.
Check that the 4 magnets are present.
3. Use a magnet to check that every second magnet in the rotor has
the same pole orientation. The rotor magnets must be N- S - N - S.
4. Connect negative from multimeter to negative of battery.
5. Set multimeter to DC volt.
6. By turning the mill wheel slowly, this will register approx. 8.0 +/- 1
volt with the diode on and 0.3 +/- 0.1 volt with the diode off with
every second magnet.
Testing speed transducer
• BROWN wire to positive of 12 volt battery. BLACK wire to negative.
• BLUE wire to multimeter.
1. Connect negative from multimeter to negative of battery.
2. Set multimeter to DC volt.
3. Bring a metallic object (distance 3 to 5 mm) up to the transducer. This will register 1.4 +/- 0.2 volt and the diode will
turn on.
4. By removing the object, this will register 12.0 +/- 1.0 volt. Diode is OFF.