Monarch Instrument POCKET-TACH 100 - Manual (Page 5)

NON-CONTACT MEASUREMENTS
Preparation
To prepare a shaft for non-contact measurement of speed, carefully
clean an area of the shaft of all grease and dirt and apply a piece of
reflective tape to the cleaned surface. Typically, a half-inch square of
reflective tape is convenient. For smaller shafts, smaller pieces of tape
down to approximately 1/8 inch (3mm) in length may be used. Always
use the T-5 reflective tape supplied. Additional T-5 tape is available in
five-foot (1.5M) rolls (see section 8.0 Options and Accessories).
Aiming
The ergonomic design of POCKET-TACH makes the non-contact
measurement of speed extremely simple. Aim POCKET-TACH at the
reflective target using the sight bars on the top surface of the instru-
ment as an aid in locating the target. A visible light projects from the
underside of POCKET-TACH parallel to the top surface and in line
with the sight bars. This design allows you to view the target on the
rotating shaft and the display on the instrument simultaneously.
Measuring
To measure, press and hold the power button on the front panel and
aim the instrument at the reflective tape on the shaft until a steady illu-
mination of the “bull’s eye” symbol in the instrument display indicates
you are on target. For speeds above 200 RPM, wait for three updates
of the display for the instrument to stabilize. At lower speeds, a few
additional updates may be required for the instrument to initially “lock
on”. Once a measurement is complete, release the power button while
still viewing the target. POCKET-TACH will continue to display the
last reading for approximately 90 seconds and then automatically
shut off.
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For surface speed measurements, gently contact the side
of the concave tip flat against the surface of the object
to be measured.
NOTE: Only a moderate amount of pressure is required to keep
the contact tip in contact with the moving object. Un-
due pressure can cause erroneous readings and exces-
sive wear to the Contact Tip Assembly.
3. Hold the instrument in position, and press the power
button until the reading is complete. A steady illumina-
tion of the “bull’s eye” symbol in the instrument dis-
play will indicate proper alignment of the contact tip
with the moving object.
NOTE: Rotational speed measurements read directly in RPM.
Surface speed measurements read directly in inches per
minute (IPM). (The display will not actually say IPM.)
4. When the measurement is complete, release the power
button while still in contact with the equipment.
5. Remove the instrument from contact with the equipment.
POCKET-TACH will continue to display the last read-
ing for approximately 90 seconds and then automati-
cally shut off.
Detaching the Contact Tip Assembly
To detach the Contact Tip Assembly, pull the grip of each of the
Nylatch
® fasteners to release them from the back of POCKET-TACH.
Remove the Contact Tip Assembly by gently pulling it from the back
of the instrument.
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