in-line digital display. There are three counter
are exhaust gas temperature and engine speed. If
ranges--0 to 10,000, 0 to 5,000, and 1 to
the exhaust gas temperature is just a few degrees
119.4--for the respective scales. The components
higher than it should be, the turbine blade life is
of the RPM indicator are inside a solder-sealed
reduced as much as 50 percent. Abnormally high
metal container to prevent dirt from entering.
exhaust gas temperature resulting from excess
You can check indicator calibration by the
engine speed can cause premature engine failure.
master tachometer generator. Compare indicator
If the exhaust gas temperature is too low, jet
RPM or percent RPM indication to the reading
engine efficiency and thrust is reduced. Either of
on the RPM indicator of the tachometer tester.
these two conditions makes engine operation
For additional information on the operation
dangerous. By using the JETCAL analyzer, you
and service instruction of the TTU-27/E tester,
can detect or prevent these conditions.
refer to NAVWEPS 17-15CM-2.
You can more accurately check signs of fuel
system trouble, tailpipe temperature, and RPM
with the JETCAL analyzer than with aircraft
JET CALIBRATION (JETCAL)
gauges. With proper use of the JETCAL analyzer,
ANALYZER
you can detect malfunctions in these systems.
Of the many factors affecting jet engine life,
The JETCAL analyzer (fig. 2-34) is a rugged,
efficiency, and safe operation, the most important
portable instrument made of aluminum, stainless
Figure 2-34.-JETCAL analyzer.