The USLS from Antrix Corporation Limited is a Space Qualified Ultrasonic Liquid Level Temperature Sensor designed and developed to sense the level of the propellant in the tank during filling operation. It has an insulation resistance of more than 100 Mohm at 50 VDC. It has a test pressure of 15 bar and capacitance of 1000 ± 300 pF. This temperature sensor has crystal frequency 1.15 ± 0.10 MHz with an attenuation in air is more than 35 dB and an attenuation of water is less than 10 dB. It uses basic element materials like AISI 304L and supports a 5-pin Lemo electric interface. This sensor works on the ultrasonic principle and uses N2O4, UDMH & water as working fluids. This temperature sensor measures 22.5 x 125 mm (sensor diameter x immersion length) and has successfully flown in all launch vehicle missions.
