Certifications &


Fuel Quantity Probes & Senders.

CiES CC-Series fuel senders are Technical Standard Order (TSO) certified to C55a and associated SAE AS405c.

View TSO-C55a | View STC/AML | View EASA STC

They have also met all the DO-160(F) and DO-254 DAL (Design Assurance Level) Level D requirements for the TSO.

Go to DO-160 Environmental

Note:  The conditions and tests required for TSO approval of this instrument are minimum performance standards. Those installing this instrument, on or in a specific type or class of aircraft, must determine that the aircraft installation conditions are within the TSO standards. TSO articles must have separate approval for installation in an aircraft. The instrument may be installed only according to 14 CFR part 43 or the applicable airworthiness requirements.

General Specification


Floats, arm lengths, and travel angles vary depending on tank dimension and application.

tso c55a general spec of the CiES fuel sender

Accuracy Range

Angular Travel Range of Sensor

0.18° CiES between angular steps.

1024 Discreet points over 180° swing.

fuel sender accuracy range through 180 degrees


Operating Temp Range

-55° to 85° Celsius (C)

-67° to 185° Fahrenheit (F)


Operating Voltage Range

9–28 VDC

Signal Output Options

Output TypeSignalRangeOutput RangeFormulaRise Time
TemperatureOutput to be the following:
Option 10-5 Vdc Square Wave-50°C to 50°C
-58°F to 122°F
FREQ 1,200Hz - 490HzTemp = 123 - (87,252.07 / Frequency)105nS
Fuel LevelOutput to be one of the following:
Opt 1 Frequency0-5 Vdc Square Wave5° - 175° Angular TravelFREQ 16,384Hz - 64HzFREQ (Hz) = 65,538 / (4 + (Deg * 5.6889))115nS
Opt 2 ResistanceResistance 0 - 280 Ohm5° - 175° Angular TravelResistance 0 - 280 Ohm
Opt 3 VoltageVoltage 0 - 5 Vdc5° - 175° Angular TravelVoltage 0 - 5 Vdc

Mounting & Installation

CiES Fuel Senders

CiES senders are designed to be a side or top mount configuration. Torque screws 18-22 inch-pounds (in lb) using a crossing pattern.

Warning: Over-torquing or using a circular pattern may cause “damage” to gasket and/or sender.

Note: Hardware is “NOT” supplied with senders unless requested. We recommend AN, AS, NAS, MS or equivalent hardware. 

mounting installation diagram of a fuel sender

SAE AS405c

CiES Fuel Senders
3.1.2Workmanship5.6Test Liquid
3.2Identification6.1Scale Error
3.3.2Humidity6.3Leak Test
3.3.3Vibration6.4Position Error
3.3.4Altitude6.5Power Variation
3.3.5Fire Hazard6.6Dielectric
3.3.6Seal6.7Maximum Operating Temp
3.4Radio Interference7.0Qualification Tests
3.5Magnetic Effect7.1.1Low Temperature
4.3Power Variation7.1.2High Altitude – Low Temp
4.4Power Indication7.3Vibration
4.5Tank Moving Parts7.3.1Resonance
4.6Filling Medium7.3.2Cycling
5.1Atmospheric Conditions7.4Humidity
5.2Vibration7.5Magnetic Effect
5.3Vibration Equipment7.6Sealing
5.3.1Linear Motion Vibration



The TSO article meets the minimum operation performance standard requirements (MOPS) for TSO C55a.

Environmental Qualification Per RTCA/DO-160(F)
4.0Temperature & AltitudeB2
5.0Temperature VariationB
7.0Operational ShocksA
8.0VibrationS (M)
9.0Explosive AtmosphereE1,2
15.0Magnetic EffectZ
16.0Power InputB
17.0Voltage SpikeB
18.0Audio Frequency SusceptibilityB
19.0Induced Signal SusceptibilityZC
21.0Emission of Radio Frequency EnergyL
25.0Electrostatic DischargeA

Next Generation Can Trust Their Fuel Gauges.

We’re committed to providing an accurate, safe and reliable fuel level reading, as well as providing you with the highest level of service. Once you have installed magnetic field fuel sensing, your fuel level sensing problems will be solved. When you see the difference, you’ll always choose us for your fuel and liquid level sending needs.