Operation; Selecting A Function; Photo Rpm Measurement - Extech Instruments RPM40 User Manual

Operation
Selecting a function
Press and hold the MEASURE button (7) and, while holding MEASURE, use short presses of the
FUNCTION button (8) to step through the modes. The available modes are: Contact RPM
measurement, Surface speed (m/min), Surface speed (ft/min), Surface speed (in/min), and
Photo RPM measurement (laser pointer will switch ON in this mode).
Note: When a function is selected it becomes the default mode of operation (even after the unit
is powered off) until another function is selected.
Photo RPM Measurement
1. Select Photo RPM measurement mode as instructed in the previous section.
2. Apply an appropriately sized square piece of reflective tape to the surface of the object
under test.
3. Press and hold the MEASURE button and align the laser pointer with the reflective tape.
Measurement distance should be limited to a distance range of 2 to 60" (5 to 150cm).
4. Verify that the Monitor Indicator (6) appears on the LCD when the reflective tape passes
through the beam.
5. Release the Measure button when the RPM reading stabilizes on the LCD.
6. If the rpm is under 50, apply additional squares of reflective tape. Divide the reading shown
on the display by the number of pieces of reflective tape squares to calculate the actual rpm.
NOTE: Bright ambient light may interfere with the reflected light. Shading the target area
may be necessary in some cases.
CAUTION: Rotating objects can be dangerous. Use extreme care.
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