Electronics International US-8A - Manual (Page 18)

Operating Information
It is not uncommon for an aircraft engine to backfire on start. This is especially true when the battery is
low. If this happens and a fire starts in the carburetor, it can cause extensive damage before the problem
is noticed. The Ultimate Analyzer can detect this problem almost immediately.
Set the High Carb Temp Limit for 150’F. This is only a recommended limit. As you get to know your
engine’s normal operating temperatures you may want to adjust this limit accordingly.
B) Selecting the Lower Carb Temp Limit: You may want to set the Lower Carb Temp Limit for
37’F. This is just above the temperature where ice will form. There is, however, a disadvantage to
setting the Low Limit for 37’F. If you fly in very cold weather where ice cannot form, the Ultimate
Analyzer will show a “Temp Prob” and the automatic scan will stop until the Carb Temp is increased
above 37’F. If this is the case, you may want to use partial carb heat or disable the Lower Carb Temp
Limit. Setting a limit to 0000 disables that limit.
Operating the Ultimate Analyzer in Your Aircraft
1. Taxi:
During taxi most of your engine temperatures will be below the Lower Temperature Limits. Therefore, to
avoid any red “Temp Prob” lights, operate the Ultimate Analyzer in the Manual Mode. In the Manual
Operating Mode the Lower and Differential Limits are disabled.
2. Run Up:
During run up you may want to look at each of your engine temperatures by stepping the Ultimate Analyzer
through the channels manually. If you want the Ultimate Analyzer to diagnose your engine automatically,
place the Ultimate Analyzer in the Scan Operating Mode. A situation you may encounter by scanning during
run up is that some of the engine temperatures (such as EGT’s) may not exceed their Lower Temperature
Limits. If this is the case, you may want to check your engine using the Manual Mode or program the Lower
Temperature Limits to accommodate scanning at run up.
3. Takeoff:
Place the Ultimate Analyzer in the Scan Operating Mode during takeoff. For the first few seconds of the
takeoff roll you may get a red “Temp Prob” light until the engine temperatures exceed their Lower Tempera-
ture Limits. The Ultimate Analyzer will automatically diagnose your engine during takeoff. A red “Temp
Prob” light will alert you if the Ultimate Analyzer detects a problem during takeoff.
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Operating the Ultimate Analyzer in Your Aircraft