PASCO ME-8932, Instruction Manual

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012–06734A Smart Timer
1
Introduction
The PASCO ME-8930 Smart Timer is an accurate, versatile digital timer and
measurement system for the student laboratory. The Smart Timer offers 0.1 ms timing
resolution and an easy-to-use memory function. The Smart Timer measures several types
of events detected with PASCO’s digital sensors, including speed and acceleration using
standard photogates. The PASCO ME-9387 Smart Pulley, the ME-9207B Free Fall
Adapter, the ME-6810 Time-of-Flight Accessory, or the ME-9259A Laser Switch also
work with the Smart Timer. The Smart Timer counts radiation emission events detected
with the SN-7927 G-M Tube/Power Supply or the SE-7997 G-M Tube. The Smart Timer
features two input channels and a 2-line, 16-character alphanumeric liquid crystal display
that indicates the operating mode and experimental results.
Features:
The Smart Timer’s memory function makes it easy to time events that happen in rapid
succession, such as a Dynamics Cart passing twice through the photogate, once before
and then again after a collision. The 0.1 ms resolution is especially useful in some
experiments, such as measuring velocity or acceleration during free fall. The Smart
Timer can calculate velocity before and after a collision between two carts using a single
timer. With the new fence design and sensing logic, parallax errors are eliminated and
timing accuracy is improved considerably over existing timing options. The Smart
Timer’s internal microcontroller also eliminates the problem of incorrect readings due to
multiple passes through the same photogate by “understanding” the type of measurement
selected and ignoring multiple passes.
The Smart Timer has many different options for timing and calculating values based on
inputs from a variety of sensors. The graphics on the keypad aid in the selection of the
appropriate timing mode. Options include One or Two Gates, Fence, and Pendulum
modes. These modes allow you to measure the speed of an object as it passes through the
photogate or between two photogates, or to measure the period of a pendulum. The
stopwatch mode lets you use the timer as an electronic stopwatch.
The Smart Timer can measure speed and acceleration for both linear and rotational
motion experiments. Alternatively, the time can be measured directly, and the speed and
acceleration can then be calculated by the student. The speed and acceleration
measurement features can be enabled or disabled using a switch inside the Smart Timer.
Use With Photogates:
The Smart Timer is optimized for use with PASCO’s ME-9204B Accessory Photogate
(available separately). These narrow-beam infrared photogates plug directly into the
Smart Timer and are used to provide the timing signals. An LED in one arm of the
photogate emits a narrow infrared beam. As long as the beam strikes the detector in the
opposite arm of the photogate, the signal to the timer indicates that the beam is
unblocked. When an object blocks the beam so it doesn’t strike the detector, the signal to
the timer changes.