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CHRONOGRAPHING
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INTRODUCTION
This not only addresses some of the questions about chronographs and their
proper use, but also to inform players how "less than ethical players"
purposely circumvent safety rules. I realize that it may give people "ideas"
on how to cheat, but if everyone knows about these nasty techniques, maybe more
people will pick up on them.
A CHRONOGRAPH
A chronograph is a device which is designed to measure the velocity of a moving
object. The first type of chronographs were the "sensor type". The
chrono had two light-sensitive sensors which marked the passing of a projectile
as a change in light levels. The computer chip in the chrony uses the simple
Velocity- Equals- Distance-Divided-By-Time equation, to determine the speed
of the paintball. The first chronographs probably wouldn't fit in an average
size garage and tipped the scales at a couple of tons. They were designed to
aid in the research and development of firearms and ammunition.
The second type of chrono is the "radar type". A radar chronograph
uses "Doppler effect" radar which detects, and measures the speed
of, a moving object. It's the same technology used for police "speed guns"
and military target tracking systems.
THE IMPORTANCE OF CHRONOGRAPHING
Paintball goggles are stress tested to absorb an impact of around 320 fps.
Velocities over 300 fps tend to break skin and cause severe bruising. Higher
velocity paintballs have been known to cause concussions (when impacting on
the temple). We don't want people to get hurt, so the limit was set at 300 fps.
You can't "guess" a paintball's velocity by the sound of the paintmarker.
(Although more experienced payers have been known to approximate velocities
for the sounds of paintmarkers familiar to them--this doesn't replace chronographing).
You can't tell its velocity by the size of the splat it makes. The chronograph,
when used properly, is the safest, most accurate way to determine a paintmarker's
velocity.
NOTE: Paintmarkers which are at velocities of over 300 fps are said to be "hot"
or "shooting hot".
THE PROPER WAY TO CHRONOGRAPH
1.Sensor Type - The ideal position is as follows.
-The end of the barrel should be at least one foot away from the front of the
chronograph and at least six inches above it.
-The barrel should be parallel to the plane of the sensors.
2.Radar Type - Rest the end of the barrel on the mount provided.
There should be a clear space of at least five feet so the radar beam is not
interrupted by bushes, walls, tress and other obstacles.
Always remember, the chronograph is NOT and impact sensor, so don't shoot it.
IF THE MAXIMUM LIMIT IS 300 FEET PER SECOND (FPS) IS IT OKAY TO SET MY PAINTMARKER
TO 300 FPS?
ABSOLUTELY NOT! Due to ambient air temperature changes throughout the day,
the effect of rapid firing on pressure and temperature of the CO2, along with
a dozen other things, will effect the velocity by up to 15 fps. Set your paintmarker
at 300 fps first thing in the morning and you'll be shooting at least 315 fps
by noon, or sooner! Even stable systems like high pressure air and nitrogen
have had velocity spikes.
THE MOST COMMON MISTAKES THAT RESULT IN INCORRECT READINGS
LIGHT. The sensor-type chronographs rely on ambient light. If it is too bright,
or too dark, the chronograph will give erroneous readings, or none at all. Because
it detects changes in ambient light, if the muzzle of the paintmarker is too
close to the chrony, the expelled CO2 will also cause confusion in the reading.
SPACE. Radar chronographs don't suffer from any of these frailties. However,
the radar chrono needs space in front of it so the beam can be projected from
the chrono uninterrupted by obstacles such as trees, buildings and walls. They
operate on any light (or in complete darkness) and because the beam is projected
out away from the shooter, the ball naturally travels right into it. Don't worry
about being irradiated. The beam is projected away from you.
Besides, if you're standing in the beam, I'm sure the paintballs hitting you
will give you a subtle hint to move.
DIRTY BARRELS. Paint and shell fragments in the barrel will slow the
ball down to bring the velocity down as much as 10 feet per second (fps). Watch
the balls as they travel; if they're corkscrewing and hooking, you know the
person chronographing has a slimed barrel.
HOLD THE PUMP. With pump action paintmarkers, if you do not hold the
pump forward when you fire, the bolt usually blows back. This results in lowering
CO2 pressure in the barrel and lowering velocities as much as 10 fps.
AIR SOURCE SHUT OFF. If the tank is shut off, unscrewed (to close the
pin valve) or low on gas, the pressure is lower. This results in VERY low chrono
readings. Players can purposely cause this to happen. They charge the paintmarker
and then turn off the power source. There is still CO2 in the valve of the paintmarker,
allowing them at least one shot. To thwart this type of "mistake",
it's best to take several shots over the chronograph. Ensure remote systems
are turned on, you can still fire the paintmarker with a hose full of CO2. If
a player seems to be satisfied (or even happy) with a velocity of 220 fps on
their semi, you might want to keep an eye on them.
DIFFERENT BARRELS. Different barrel lengths and interior finishes will
give different readings on the same paintmarker. Shorter barrels give lower
readings than longer ones. Players could switch barrels after chronographing
and change their velocities, this can happen intentionally or out of ignorance.
Also if the interior, or bore, of the barrel is smaller than your paint, it
will slow the velocity as well (because of increased friction between the barrel
and the moving ball). Switching to a barrel which is of a larger bore (but similar
outward appearance) will result in a drastic raising of velocity. Sometimes
as much as 25 fps.
PAINT. Old paint, which has swollen slightly, will give slower velocities.
(Again, because of increased friction.) Load fresh paint and velocities start
to climb. Due to the fact that different brands (and even different lots of
the same brand) vary in diameter, always chrono with the paint you're going
to be using that day.
LIQUID OR GAS. Some paintmarkers run on liquid CO2; check to see if
the paintmarker has a siphon bottle. Those other CO2 systems that rely on gas
have to be checked too. Any paintmarker running on gas will have significantly
higher velocities if they manage to pull liquid. When you chronograph, you want
the worst-case scenario. Force the paintmarker to draw liquid (by tipping it
so liquid from the tank will flow into the valve and then firing a few shots)
and chronograph. A paintmarker chronoed a 260 fps on gas will go over 300 fps
on liquid. Paintmarkers with regulators and expansion chambers usually won't
go liquid, as long as you're not pounding the paint down- range like you're
trying to put out a forest fire. (More on that later.) Don't make markers like
the Automag take liquid, however, they could get damaged internally.
DISCONNECTED REMOTES. Disconnecting the hose from your remote set-up
will cause a drop in pressure in your paintmarker, resulting in lower velocities.
This is why in most tournaments you are not allowed to fire/disconnect after
you have been eliminated or the game has ended.
FRESH FILLS. A freshly filled CO2 tank will yield very low velocities.
I've seen velocities climb 100 fps as tanks warmed up! If the tank is frosty,
tell them to go get a warmer one. (Usually the field will lend you a tank, if
you don't have another one.)
WHAT TO LOOK FOR DURING A GAME
Listen to the paintmarker as it fires. If you hear a pop, pop, pop, KAPOW!
it's a good chance that last shot was hot (over 300 fps). Watch for players
with incredibly unbelievable range. If your paintballs are dropping at their
feet (and you're at 280 fps) and your opponent's are zipping straight past your
head, chances are he's hot. If the paintball REALLY hurts when it hits you at
longer ranges, ask the shooter to re-chrono.
"CHEATING" THE CHRONOGRAPH
All of the above mentioned mistakes can be done intentionally. Also there are
other deliberate methods.
1. A string of rapidly fired shots tends to cool the CO2 down. This results
in lower velocities. Watch for players shooting lots of paint just before they
chrony. Or especially if they seem to be shooting a lot of just air.
2. This is pretty much reserved for Autocockers, but other compatible operating
systems can be similarly modified. Basically, there is a hole about halfway
down the bolt that allows air to come up from the valve and then out the front
of the bolt. Some players have TWO holes, one on either side, of different diameters.
One hole will give low velocities, and the other will bring the paintmarker
over 300 fps. You chrono safely with one hole, and turn the bolt (easy to do
with a 'Cocker) and you've changed your velocity from 280 to 310 fps! This is
not something that happens by mistake.
WHAT WE DID BEFORE CHRONOGRAPHS WERE INTRODUCED TO THE SPORT
Well, we just listened. Some fields had you shoot at a tree at a certain distance,
if the splat was bigger than your hand, you paintmarker was shooting hot. Luckily
we discovered chronographs a few years after the sport's inception.
WHEN TO CHRONOGRAPH
Here is a quick reference list of when you should chronograph your marker.
MANDATORY
1. First thing in the morning, before play.
2. Just before lunch.
3. After lunch.
4. After adjusting, replacing or repairing internal components.
5. After changing barrels.
6. After changing your air source (putting on a new tank)
7. When requested by field staff.
8. When requested by another player.
9. Any time you feel you should, just in case.
FOR EXTRA SAFETY
1. After disconnecting, and subsequently reconnecting, your remote hose.
2. When the weather changes (cloudy to sunny, warm to hot, rainy to clear --
I'm sure you get the point).
In the event that you suspect someone is shooting hot, politely point it out
to them. Don't go accusing someone of cheating, even if you know they are. This
will only make the situation worse. If calmer heads prevail, even the intentional
cheater will comply and go and turn his paintmarker down. If you say, "You
should hold the pump when you shoot, to get a good reading", instead of
"Hey you cheating so-and-so, you're going to shoot my eyes out with that
piece of junk," the person in question will be more amiable to changing
their ways.
I have strong personal feelings about those who intentionally play with a hot
marker. As far as I am concerned, that's assault with intent to maim.
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