Sensors William Widjaja

What is a sensors

•A sensor is a type of transducer. Direct-indicating sensors. Other sensors must be paired with an indicator or display, for instance a thermocouple. Most sensors are electrical or electronic

What is today

•Due to the difference in the gravitational force in the lunar surface. Conventional Sensors methods do not work optimally. In this short presentation discuss about 4 measuring sensors

Why use sensors ?

• A continuous monitoring of liquid is essential for storage because it allows operators to control the fluid management better and detect contamination and control both temperature and pressure to maintain the health of the storage tanks

4 Pressure Sensors

1. Pressure Sensors

•Pressure sensors is the measure of pressure of gases or fluid. A pressure sensor generates a signal to signify the pressure imposed and usually conducted with electrical sensors

2. Strain Sensors

•Strain gauges are sensing devices that change resistance at their output terminals when stretched or compressed. They are bonded to the surface of a solid material to measure its minute dimensional changes when put into compression or tension.

3. Optical Sensors

•Optical Gauge Sensors concept is capable of determining fuel and oxidizer mass quantities in low to zero gravity applications utilizing wavelength of light for the optical attenuation measurement

•http://www.sbir.nasa.gov/SBIR/abstracts/04/sbir/phase1/SBIR-04-1-X6.05-8229.html

4. Compression Mass Gauge

•CMG employs a small bellows to periodically change the tank volume by a small fraction. The resulting change in fluid pressure is measured, and thermodynamic relations are used to compute the volume of gas (and thereby the volume of liquid), assuming that the bellows compresses the entire volume of gas uniformly

•http://www.swri.org/3pubs/IRD2000/18-9181.htm

Criteria for Sensor SelectionCriteria Strains Optical CMG Pressure

Accuracy

Complexity

Energy Required

Technology Readiness