AETNA ENGINEERING Tach Tape TT-100 Specification Sheet

TT -100
Tach Tape
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INSTRUCTIONS
SPECIFICATIONS
Temperature range:
-30 F to +160 F. (-35 C to +70 C)
Gear pitch equivalent: approximately 7 dlametral pitch.
Maximumcontinuous len2th:
100 feet (30 meters)
Caution: Do not expose tape to strong AC or DC magnetic fields and use only with Dynalco
magnetic pickups.
FUNCTION:
Provides a convenient, simple and low-cost means to activate Dynalco magnetic pickups in
speed and frequency measurements.
USE:
An inexpensive substitute for large split gears, slots in shafts, drilled holes in flywheels,
etc., for magnetic pickup speed sensing.
DESCRIPTION & CHARACTERISTICS~
Dynalco Tach Tape is a strip of flexible magnetic polymer. bn one side it has a pressure-
sensitive adh€sive protected by a peel-away backing. This adhesive will adhere to a wide
variety of surfaces, including most plastics and metals.
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Because of its unique magnetization and arrangement of slots, a series of alternate magnetic
poles are generated along the length of the tQpe. A Dynalco magnetic pickup becomes
activated when placed perpendicular to the tape surface.
Figure 1 demonstrates that the tape performance is better than an a-pitch gear when the
air gap is larger than .050 inch (1.2MM). This is especially welcome in cases where a
small air gap is difficult to maintain or space is too restricted. to install split gears
because the Tach Tape-Dynalco pickup combination is so well suited to large air gaps.
Because of centrifugal forces acting upon the tape when rotating, a safe maximum speed shoulq
be observed (shown in Table 1). If greater speeds are required, a fiberglass reinforced
plastic tape (such as one inch wide strapping tape #ST-40, Superior Insulating Tape Company)
may be wrapped over the magnetic tape (two layers as shown in Figs. 2&3), which quadruples
the maximum safe speed. (Pickup senses through reinforcing tape)
The tape should not be @xposed to strong AC or DC magnetic fields and should only be used
with Dynalco magnetic pickups to prevent possible de-magneti~ation.
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This table assumes the Tach Tape has been applied according to the instructions which
folJow.
TABLE 1, MAXIMUM SAFE SPEED
SHAFT DIAHETER
WITHOUT REINFORCED TAPE
WITH REINFORCED TAPE
3 IN
(7.5 cm)
2500 RPM 10,000 RPM
6 IN (15 cm) 1800 RPM
7,200 RPM
9 IN (23 cm) 1500 RPM
6,000 RPM
12 IN (30 cm) 1200 RPM
4,800 RPM
24 IN (60 cm) 900 RPM
3,600 RPM
36 IN (90 cm) 700 RPM
2,800 RPM