Longacre 50370 Temperature Compensated Tire Pressure Gauge - Manual (Page 2)

TO TAKE TEMPERATURE COMPENSATED TIRE PRESSURES:
(compensated or corrected back to a standard temperature)
Connect the tire probe
included on the lower right side of the gauge. Note the wide
and narrow spades
(if connected backwards the unit will read backwards)
.
The wide spade is toward the top. Insert the probe into the
tire tread area much as you would if you were taking
temps off the track. Allow a few seconds to stabilize.
Now push the lock temp button. The display will
change as shown and the gauge’s microprocessor will
now compensate or correct the pressures as if the tire was
at 80
0 F
(this may not be the actual pressure at that point)
. Adjust the tire
pressure as needed. To do the other tires repeat the above
proceedure. Push lock temp to reset
(returns to TRUE FACTORY
Calibration)
, then use probe and lock temp again to lock
the new temp. If you are absolutely sure all tires are at the same
temp you can skip the probe and lock temp on the other tires.
To return to true factory calibration push lock temp button again.
True Factory Calibration will appear in the lower right of the display.
How TEMPERATURTE COMPENSATION Works
This Professional Tire Pressure Gauge will measure and store on the display 4 tire pressures and 12
tire temps in the traditional way.
It will also
(optionally)
compensate or correct tire pressures back to a standard temperature. The pres-
sures you set before the race determine the critical pressures on the track. The ultimate temperature
on the track will be the same regardless of the starting temperature. If you set starting pressures at
different temperatures you will get different and inconsistant track pressures. For example if you set
one at 32.3 psi at 80
0 and you later set it at the same 32.3 psi but at 95 0
(tires sat in the sun)
the pres-
sure, if it cooled down to 80 0 , would be 31.0 psi. Would that 1.3 psi make a difference on your
car? With this gauge you can measure the tire temp
(in the pits before the race)
and the gauge will
(optionally)
correct the pressures as if you set them all at the same standard temperature.
1/09
31.0
Press Comp
80
Temp Lock
95
Compensated tire pressure
(not necessarily true
actual pressure)
Pressure compensated
to this temp
current
tire temp
TRUE FACTORY
Calibration
is missing, indicating
Compensated Pressures
OTHER IMPORTANT NOTES:
• Adjustable probe tip - adjust probe depth as prefered & tighten lock nut against body. CAUTION: To read
temps quickly it MUST be small & delicate and can be broken easily. Use yellow protector.
• Low batt indicatorshows on display. Replace battery on back w. a quality 9 volt Alkaline. Battery life is
approx. 25 hours. An auto-shutoff shuts gauge down after 1 hour.
• Must say “TRUE FACTORY Calibration” on lower right of display for correct (uncompensated) readings.
• Backlite shortens battery life somewhat. See button to right of display. Auto-shutoff after 2 minutes.
• Keep clean and dry. Avoid strong magnetic fields (caster camber gauge magnetic adaptors?).
• 3 air bleed buttons - use just 1 or all 3 for faster bleed-off.
FOR METRIC CONVERSION:
• In normal pressure mode press
mode
and hold 5 seconds. Will stay until changed again.