*** WARNING ***
When using the Pro-Tach Chronograph, it is your responsibility to provide safe
conditions for discharging your firearm. Proper eye and ear protection must
be used, along with a suitable backstop. Your firearm must be aligned with
the sight alignment targets supplied in order to avoid hitting the Pro-Tach
Chronograph and causing a dangerous ricochet. Deflection shields are NOT to
be placed in front of the Pro-Tach Chronograph, as they may cause a bullet to
ricochet toward the shooter or bystanders.
Velocity readings obtained with the Pro-Tach Chronograph should not be used to
obtain cartridge combustion pressure. In order to avoid possible injury when
using reloaded ammunition, make it a standard practice to watch for excess
pressure indications.
Competition Electronics, Inc. assumes no liability for any property damage or
personal injury which may result from the improper use of this product.
The recommended battery for proper operation of the Pro-Tach Chronograph is a
9-volt alkaline battery, such as the Duracell, or equivalent. The battery
compartment in located on the bottom of the Pro-Tach, and its cover is held to
the case with two #4 tapping screws. To install the battery, simply remove
the battery compartment cover and connect the battery to the battery snaps.
Replace the cover, and fasten securely.
The Pro-Tach Chronograph operates on the principle of measuring the time it
takes for a bullet to travel from the first bullet shadow sensor to the second
bullet shadow sensor. The sensors, mounted internally in the case, gather
light through the two slits in the top of the case. The shadow of a bullet
passing over each sensor generates a signal which the micro-processor detects,
converts the elapsed time between sensors to velocity and displays the
velocity on the LCD screen.
The Pro-Tach Chronograph may be mounted on a camera tripod or set up on a
table. The muzzle of a pistol should be 5-10 feet away from the Pro-Tach,
10-15 feet away with a rifle. The distance is not critical, but it may need
to be longer when using rifles in order to keep from bending targets with the
muzzle blast. Mount the supplied targets in the front and back slots located
on the top of the Pro-Tach case. On sunny or very bright days, the diffuser
hoods must be used to obtain accurate readings. Properly positioned, the
diffusers are directly over the bullet shadow sensors.
Shooting through the oblong holes in the targets assures correct alignment
with the sensors and greatly reduces the chances of hitting the Pro-Tach.
Line up the horizontal bars on the targets with your sights. The bars in the
middle of the oblong holes are for iron sights, which is also how high the
bullet should pass over the Pro-Tach. The upper bars are for scopes and allow
for a one inch difference between the scope and the guns bore line.
IMPORTANT: Check the bore line-to-scope distance, and aim the crosshairs on
the scope that much higher than the iron sight marking on the targets.
Turn on the Pro-Tach by moving the power switch on the side of the case toward
the display. The display should read “8888”. It is also normal for it to
read “00”, followed three seconds later by “ERR”. Move back 10 feet and fire
a shot. The display will show your velocity and will hold it on the display
until the next shot. If a duplicate velocity occurs, the period in the
display marked “dup. vel.” will appear. If the third velocity is also the
same, the period will disappear. The period will alternate on and off for as
long as duplicate velocities occur.
The Pro-Tach chronograph has a low battery indicator built into the unit. If
the battery is nearly dead, the period marked “low bat” will appear on the
display. The battery should last for about 20 hours under continuous use.
The Pro-Tach Chronograph will show the number of shots and provide an average
velocity reading per shot string. To do this, the unit must be reset prior to
each shot string. Reset is accomplished by turning the Pro-Tach off for three
seconds, then turning it back on. After the shot string has been fired, Pass
your hand (or finger) QUICKLY over the fro bullet shadow sensor in a front-toback motion. You may have to remove the front target to do this quickly
This will cause the Pro-Tach to display the number of shots fired for one
second, followed by a display of the average velocity for 1.5 seconds,
followed by the error indication “ERR”. Varying light conditions may prevent
these displays from appearing every time. Thus, it may be necessary to pass
your hand over the sensor again. In any case, the number of shots and average
velocity displays may be repeated as many times as you wish. Just remember to
reset the Pro-Tach before firing the next shot string.
The Pro-Tach unit provides error indication by displaying “ERR”. Before it
gives an error indication, however, it will show the number of shots fired and
the average velocity. “ERR” is displayed when the first bullet shadow sensor
detects a shadow, but the second bullet shadow sensor does not. The sun
shining directly onto the bullet shadow sensor “eye” can also cause an error
indication. To prevent this problem, be sure to use the diffuser hoods and
change the angle of the Pro-Tach to the sun. Muzzle blast is another common
cause of error. Moving back a few feet farther from the Pro-Tach will solve
the problem.
The Pro-Tach will operate indoors using tubular incandescent (filament) bulbs.
Fluorescent bulbs WILL NOT WORK, because they cause the Pro-Tach to
continuously show random velocity readings, or “ERR”. Strong fluorescent
bulbs used to light the room may also cause continuous random velocity
readings. The incandescent bulbs should be mounted approximately 18 inches
directly above the bullet shadow sensors in the case. The bulbs should be 25
watts of the FROSTED type. A simple structure made of wood serves well for
mounting the bulbs.
A blast shield mounted in front of the first bulb will protect the bulb
filament from being damager by the muzzle blast. Use the supplied targets as
described in the outdoor lighting section. If you experience any trouble, try
using the diffuser hoods and move the bulbs closer. Or, leave the bulb
distance the same, and use 40-watt tubular bulbs. An “ERR” reading usually
means too much light. Or the second bullet shadow sensor is not picking up the
bullet. No reading at all probably means you don’t have enough light.
The Pro-Tach Chronograph operates best on cloudy days. If you look up at the
sky through a rectangular tube, you see what the bullet shadow sensor sees.
On a sunny day, the amount of light coming through the tube is actually less
than on a cloudy day, because the clouds diffuse the light and redirect it
straight down into the bullet shadow sensor. This is the best condition for
the bullet to cast a good shadow on the sensor. The diffuser hood actually
simulates a cloud above the sensor. That’s why it’s advisable to use the
diffuser hoods on sunny days.
The second problem experienced with sunny days is the sun reflecting off the
bullet. These reflections can cancel out the shadow, as well as cause bad
velocity readings. Using the diffuser hoods can help eliminate reflection
problems. If reflection problems persist, the best solution is to operate the
Pro-Tach in the shadow of a building or opaque wall. Trees, however, do not
provide a good solid shadow. Make sure the bullet shadow sensors still have a
clear view of the sky, but the bullet path over the sensors is in the shadow.
This way, the sun can’t reflect off the bullet, but the maximum amount of
light form the sky is still available to operate the bullet shadow sensors.
When using sabots or gas checks, there is a chance they may depart from the
bullet path and hit the Pro-Tach. This usually damages the display.
For archery we recommend you do not use the cardboard targets. Stand about an
arrows length away from the Pro-Tach and, if possible, use a black tip on the
arrow. The arrow should travel approximately 4-10 inches above the unit.
Arrow length makes no difference, as the start of the shadow triggers the
shadow sensors.
For shotgun chronographing, use only the front target, and stand with the
muzzle of the gun about four feet back from the Pro-Tach. If you stand
farther away, the shot spreads out, causing inaccurate velocity readings.
Also, the wad will separate from the shot column and may hit the Pro-Tach or
the target.
Temperature Range: 32 to 95 degrees Fahrenheit
Velocity measuring range: 75 to 4500 feet/second
Accuracy: .5%
Please call us before you send the unit back. We may be able to tell you if
the unit is malfunctioning or if there is some operating consideration that
needs further explanation.
A pack of eight targets and two diffuser hoods is available. Poster board
available at your local art supplies store can be used to make your own
targets, if you wish. Just copy the outline of one of the supplied targets
for correct size.
The Pro-Tach unit may be cleaned using DuPont PREP-SOL, a product available at
automotive paint stores. PREP-SOL dissolves most bullet waxes.
Competition Electronics, Inc.
3469 Precision Dr.
Rockford, IL
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