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9.
OPERATING PRECAUTIONS
9.1 Non-Contact Measurements
(1) Measurement Distance
The maximum measurement distance of 30 cm as noted in the
specifications is applicable for a 12 mm×12 mm reflective mark
on a flat surface and light shone on the reflective mark perpen-
dicularly to the mark. Under the following conditions, the maxi-
mum usable measurement distance will be shorter.
① When the reflective mark is applied to a curved surface (e.g.,
when the reflective mark is applied to a shaft.)
② When the reflective mark is cut smaller than its normal size.
③ When the light is shone on the reflective mark at a angle re-
moved from the perpendicular.
(2) Method of Shining Light Onto the Reflective Mark
The HT-5200 measures r/min by the existence or lack of reflected
light. Detection will, therefore, not be possible if light is con-
stantly shone on the reflective mark. Shine the light from the HT-
5200 onto the rotating body so that during each revolution of this
body, there is a time in which the light is striking the reflective
mark and a time in which the light does not strike the reflective
mark.
Particular care is required when the reflective mark is applied near
the center of the axis rotation.
Red light
Reflective mark
Rotating body
Center of
rotation
[Proper Application]
(There is a time at which red light is
striking the reflective mark and a time
when it does not.)
[Improper Application]
(Light is always striking the re-
flective mark.)
