The FD-T Tachometer measures the rotational speed (RPM) of a propeller. A photoelectric sensor detects the propeller blades and the tachometer shows real-time RPM on a four-digit LED display. Pressing the button sets the number of blades on the propeller and obtains the maximum RPM value.

Operation:

1. Normal operation

After connecting the battery, aim the lens on the end of the tachometer at the propeller, keeping the distance between 5 cm and 15 cm. Continue reading the speed (RPM) until the displayed value is stable.

2. Using with propellers having more than two blades

Hold the key and connect the battery. The LED display will show a number increasing from 2 to 9. Release the key when the number on the display equals the number of blades on the propeller.

3. Reading maximum RPM

Hold the button while pointing the tachometer at the propeller. The display will show maximum RPM. Release the button to return to real-time display.

Note: The FD-T is designed for use in daylight!