Electronics International CGR-30P - Manual (Page 45)

47
6. Fill the fuel tank to the ¼ level. Set row #2 “Value” to
the ¼ tank value. Wait for the “Current Cnts” field to
stabilize. Use the “Use Current Cnts” field to transfer the
“Current Cnts” to the “Counts” field for row #2.
7. Repeat step 6 above for the ½ full fuel level.
8. Now you are going to find the maximum measurable fuel
for the tank. Start at the ½ fuel level and add two gallon of
fuel at a time to the Fuel Tank. Look for the “Current
Cnts” to change more than 5 counts. If the “Current Cnts”
change 5 or less, this is the maximum measurable fuel for
this tank and the last calibration point. Enter the current
fuel level in the “Value” field and transfer the “Current Cnts”
to the “Counts” field for row #4.
9. Be sure to save the Map by using the “Save This Map Data” field at the bottom of the
screen.
Important Information (Must Read):
- If the “Current Cnts” field decreases as you add fuel, start with row #7 and work up.
- Do not leave any gaps in the rows between the calibration points.
- The “Counts” column should increase 10 counts or more for each gallon of fuel added to the fuel tank.
- Some fuel sensor floats reach the top of the tank before the tank is full. If this is the case, the CGR-
30P will only display up to the measurable fuel level. The Fuel Tank reading on the CGR-30P will
hang at this level until fuel in the tank drops into the measurable range. This is a common issue with
many aircraft fuel systems.
- The CGR-30P can provide accurate fuel level readings for straight and level flight when the fuel level is
in the measurable range. By calibrating the CGR-30P to the fuel tank, nonlinearity in the tank’s shape
and nonlinearity in the Fuel Level Sensor will be compensated for. The CGR-30P can not correct for
inconsistent or non-repeatable readings from a Resistive Float Sender or the non-measurable range of
the tank. Unfortunately, many Resistive Float Senders (and in some cases even new units) exhibit
non-repeatable problems. If you find inconsistent or inaccurate fuel level readings (due to a defective
Resistive Float Sender), you must have the sensor replaced or repaired. Read the “Important Notice”
in the CGR-30P Operating Instructions. E.I. manufactures a P-300M Magnetic Float Sensor that can
replace a resistive float sender. See the E.I. price sheet for further information.
E.I. Magnetic Float Senders – These senders are accurate and repeatable. They have one moving
part (a magnet) and are not affected by oxidization or corrosion. This sender can replace a resistive
float sender only when used with the CGR-30P system. This sender can not fix a non-measurable
range issue.
E.I. Capacitive Probes – The CGR-30P system will accept E.I. capacitive fuel level probes (P-300C).
Generally these probes are difficult to adapt to a fuel tank incorporating a resistive float sender.