T77430-11
Airpax T77430-11 Tachometer | With Input 115 Vac ±10%, 50-60 Hz | 24 VDC (23-30 VDC), standard (750 ohm analog load) | 20-30 VDC with 600 ohm analog load, 10 watts maximum.
TACH-PAK 3 is a single-input industrial tachometer that measures the rate of events. Using various sensors, TACH-PAK 3 can measure events as simple as the speed of a rotating shaft, the rate at which paper passes through a press, or as diverse as the rate at which liquid flows through a pump.
A speed sensor placed near a target, such as a rotating gear, generates a repeating electrical
pulse. The rate of repetition is proportional to the rate of the event you want to measure
and represents the input frequency. TACH-PAK 3 measures this rate in number of pulses per
second (hertz). This input signal from the sensor is conditioned, analyzed by a microcom
puter and routed to the outputs.
TACH-PAK 3’s microcomputer uses a scheme of data acquisition called adaptive period
averaging, a unique frequency measuring method in which the number of periods averaged
changes with the frequency to obtain optimal accuracy. At input frequencies of 100 Hz and
above, the outputs are updated every 30 milliseconds.
TACH-PAK 3 provides three scaleable output types:
• 0-1 mA DC meter output
• 0-20/4-20 mA DC analog output
• Four Form C (SPDT) relay setpoints
To set up TACH-PAK 3, first determine how each output should behave in your application,
then enter the setup information as thirteen “constants” through TACH-PAK 3’s internal
control panel. (See Section 4.) The constants are stored in TACH-PAK 3’s electrically
alterable read-only memory (EAROM). They can be viewed and altered individually in much
the same way you set a digital watch