1. Title of the invention
Fixture to Test the Flow Sensor of Aircraft Oxygen System.
2. Field of invention
This invention is related to the manufacture, testing and quality assurance of Aircraft Oxygen System.
3. Use of invention
This invention is used to test the Flow Sensor of Aircraft Oxygen System.
4. Prior art
There was no previous test fixture available for the subject Flow Sensor.
5. Draw backs of prior art
Not applicable, as this is a new fixture developed for the first time.
6. Comparison between prior art and present invention
Not applicable, as this is a new fixture developed for the first time.
7. Aim of the invention
Aim of the invention was to develop a simple and effective fixture to test the -subject. Flow Sensor of Aircraft Oxygen System.
8. Summary of the present invention
Flow sensor is a part of oxygen system, and is fitted on Aircraft .The flow sensor provides flow indication to the pilot whether the oxygen supply flow, is ON or OFF. The test fixture is used to check the serviceability of the subject flow sensor by simulation.
9. Brief description of drawings
FIG. 1: View of Test Box
FIG. 2: Schematic Diagram of Test Box

FIG. 3: Set-up of Test Fixture
10. Statement of invention
This invented Fixture is useful to check the serviceability of subject Flow Sensor in Lab before fitment on the Aircraft.
11. Detailed description of invention
a) Flow sensor is a part of oxygen system, of an Aircraft The flow sensor provides flow indication to the pilot whether the oxygen supply flow is ON or OFF.
b) The test fixture consists of a wooden stand , a test Box, a flow control valve, a blinker and outlet hoses
c) Wooden stand provides the mean to hold flow sensor in vertical position and to integrate test box, flow control valve, blinker and flow sensor under test.
d) Test box consist of Supply on-off, switch Blinker On-Off. switch, 3 pin Connector, Connecting wires, Supply indicator and supply terminals for 28 V DC. .
e) Flow Control valve is used to control the flow drawn by the Flow sensor during test.
f) Blinker provides the indication of Flow.
g) Hoses are used to connect the Flow sensor from Pressure source and to the outlet flow-meter.
h) To test the Flow sensor, it is to be connected to the inlet of Flow Control valve
on wooden stand using a pipeline. , .
i) The Inlet hose is connected to Flow sensor to provide the Pressure input to the unit.

j) The Electrical connector of the Flow Sensor is to be connected to the 3 pin connector of the Test Box.
k) The Input Pressure supply is given to the Flow sensor by external source.
I) Electrical power supply of 28. V DC is provided to the flow sensor under test from a DC power Supply unit.
m)The Flow control valve is opened slowly and steadily and the blinker is observed. The blinker activates at a specified oxygen flow rate.
n) The oxygen flow rate at which the blinker activates is compared with the specification in test schedule.
o) The testing of flow sensor is completed in the above mentioned procedure.

Claims
1. Design of the test box with Flow indicator, electrical connection, DC Power supply ports and toggle switch.
2. Integration of the On-Off valve, Blinker and test box on the wooden stand to make a complete fixture.
3. Testing of the flow sensor with calibrated release of the flow through On^Off Valve to achieve the test results.